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Articles on metal detecting and gold prospecting. Forums about metal detecting for coins, gold, relics, jewelry plus equipment reviews and more.

  • Steve Herschbach
    This page is a free service to help people find mining claims for sale or lease in Alaska. Listings here may be deleted after 6 months but in general the ads are left up until you notify me that you want them removed. To have your ad listed here,?email your ad?with details.?Use the existing ads as your template. Note that since I am a prospector it can take a week or more for listings to be posted.
    VERY IMPORTANT!?DetectorProspector.com and Herschbach Enterprises take no responsibility for the accuracy of the information presented here. A listing on this page is in no way an endorsement or recommendation of the property listed. Contact the person listing the claim if you want more information. Research all claims thoroughly before purchase. Read?Investigate That Claim Before You Buy. Also see?Gold From Water and other mining scams?(look for Free Downloads pdf link). If you have any doubt about what you are doing consider hiring a qualified person or company to validate a potential claim purchase. If you know of a listing here that you believe to be fraudulent in any way please alert us at the email address above.
    Ruby Mining District?- Added 6/24/20.?Two 40-acre state mining claims in the Ruby Mining District including equipment. I have been running the old timers’ tailings with consistent results over the last 4 years. AK620507 & AK620506 are located along Midnight Creek (great water). There is over 1000 linear feet of tailings along the creek which are anywhere from 20 to 50 feet tall (lots of material). ?Sale includes Ford 750 Back-hoe-loader, 6-inch water pump, Shaker wash plant, clean up equipment, 1995 Ford E-350 Cube truck, Keene 5-inch suction dredge with 3 stage sluice and air, various tools, hoses, generators, spare parts. Reason for selling is that I am getting older and just can’t work as hard as I used too (Desk job last 26 years). ?The last several years I have taken about 2 weeks off from my job to work the tailings with the following results:?
    ? ? ? ? ? In 2017 I fed wash plant for 23.5 hours and recovered 3.7 ozt of gold?
    ? ? ? ? ? In 2018 I fed wash plant for 9.0 hours and recovered 1.1 ozt of gold?
    ? ? ? ? ? In 2019 I fed wash plant for 15.3 hours and recovered 2.1 ozt of gold?
    Serious inquires only please.?You can email me for more information and pictures at cessnadrivergus@yahoo.com?Cell: 612-201-9372 please leave a message if I don’t answer (too many Scammers & Spammers).?$29,500 for the claims and equipment. Here are a few links to video of my mine:?
    https://www.youtube.com/watch?v=-95kXz3V0WI
    https://drive.google.com/file/d/1amiSFI-sPsDn0ORAxl_XJac7PXah6hs9/view?usp=sharing
    Cherry Creek?- Added 6/7/20.?I have 7 claims on Cherry Creek ?South of Boundary,?Alaska. There is road access to both ends of the claims they are still mining above these claims ?there are 6 virgin claims and one that has been mined but needs to be mined again . It produced over 200 oz when it was mined in 1990. I am asking $20,000 per claim,?they are very good ground and they are all state claims if interested contact me at ? websterscrap@yahoo.com
    882 Acres on McWilliams - Gold Trail w/Patented Placer Claims? (Estate Sale)
    Click on Lot Links for Approximate Mid-Locations of Listed Lots.? Lots start from Headwaters of Claim and continues 7 miles downstream.? (HINT: Lot J-22 is farthest, upstream lot and list continues downstream to end lot.)? Lot J-22, Lot J-21, Lot J-20, Lot J-17, Lot J-31, Lot J-18, Lot J-16, Lot J-15, Lot J-1, Lot J-30, Lot J-2, Lot J-3, Lot J-4, Lot J-5, Lot J-6, Lot J-7, Lot J-8, Lot J-9, Lot J-10, Lot J-11, Lot J-12, Lot J-13, Lot J-14, USS 6070, Lot J-25, Lot J-27, Lot J-28, Lot J-26, Lot J-24, Lot J-23, Lot J-32, Lot J-33, Lot J-34, Lot J-35, Lot J-36, Lot J-37, Lot J-38, Lot J-39, Lot J-40, Lot J-41, Lot J-42, Lot J-43
    Includes any and all abandoned buildings and equipment, without warranty of any kind, 41 Contiguous Claims and USS 6070, encompassing 881.96 acres of Private, U .S. Patent Land running mostly on both sides of John's Creek and Chunilna Creek.? Ground Access:? 36 mile trail from the loading docks of the Alaska Railroad to the J-2 Claim.? Air Access:? 2,800' airfield off J-14 and area of USS 6070.? (RUNWAY CURRENT CONDITION UNKNOWN)?
    Past Placer Mining Activity Over 6,749.84 Au recovered troy oz. from 361,413 cu. yd. with 5,093 hr. worked.?Virgin ground believed to still exist.? Value of minerals not given a value in sales price.? Title Insured in the amount of the Sales Price.? Future Land Individual Sales Forty-one (41) Individual lots approx. 19-20 acre lots already subdivided into 2 Mining Claims; MS224, or 282.84 acres, and MS2252, or 519.14 acres; plus one 79.98 acre lot, USS 6070, all which can be divided into 42 individuals lots, allowing for easier divesting of this investment, in the future.?List Price:? $1,400,000?Contact Greg Erkins (907) 562-3382 gregerkins@hotmail.com or gerkins@gci.net?
    Greenstone Creek?- Added 4/13/20. In the Ruby Mining District. For sale 13 State of Alaska claims enclosing 760 acres of placer and lode claims. The hillside placer ground is very shallow to bedrock. I deal for a small placer operation and hardrock exploration. The extensive list of equipment includes dozers, excavator, loader and many more items. 767 troy ounces of coarse gold was mined in two recent seasons. A potential resource of >900 ounces from 35,000 bank cubic yards of pay gravel (0.03 oz/bcy) has been outlined by test pitting for production in 2020. Fully permitted through 2023. The portable camp ?of three trailers and one RV motorhome and can comfortably accommodate up to 7 persons. Small generators provide electricity to all buildings. Start mining or detecting gold nuggets this summer. Complete purchase required. Motivated seller. Asking $1,000,000 for the placer, lode, camp and all equipment. Contact Jim Halloran (agent) at augeojim@yahoo.com for more information.
    Hansen Gold Claims Near Nome?- Added 2/26/20.?Budd Creek, Windy Creek, Million Creek, Gold Run Creek group North of Nome, Alaska.?34 State of Alaska, 40 acre?claims for sale on 2 adjacent streams on the American River north of Nome. Approximately 9 miles of stream placer. Access is from the end of the Kougerok Road ?then along established trail for approximately 25 miles. 4,000' runway at end of Kougerok Road.?Historic Bucket Line Dredge (Walter Johnson) on Windy Creek. (1914 intermittently until 1929). Estimated 85%of valleys are virgin.

    All claims are shallow (running 3 - 12 ft. to bedrock) Some areas of permafrost because of 2-4 ?of overburden. No timber on claims. Plenty of Water to work. No anadromous streams.?Some ground worked by hand during the gold rush. An exploration program conducted in 2018 with a small backhoe found samples to 0.1 oz/yd. and average of all tests from top of gravel down averaged 0.03/yd.?Most tests did not reach bedrock and only a few claims were tested. Sale or lease to qualified Placer Miner. All claims sold as a group.?Call or e-mail for more information. Jim Hansen ?eaglejim39@yahoo.com 907-707-1090 or 907-304-1756
    American Creek / Game Creek?- Added 2/10/2020. Seventy?miles north of Nome, six State of Alaska 40 acre claims next to old Massey dredge American Queen. Main cabin, tool shed, 2x old bunk houses, water pipe about 35 yards from the main cabin. ?There is quite a bit of equipment and some fuel on site. Previous owner 4-wheeled in from Salmon Lake parking. There is another route that the old tractor trail/railroad used. 2x Landing strips near claims. ?Military family now unable to work claims due to family situation.
    https://drive.google.com/open?id=1at0JMLXd3A3twCGiT-hl9-uFx1LtA10V
    For Sale $50,000 OBO. Please call or email for more information: Sonny 907-406-5122??outlaw13a@gmail.com
    Porcupine Creek - Updated 2/26/20.?PARTNER FOR JV IN 2,700 ACRE gold mining claims in South Central Alaska located N. of Glennallen in a Porphyry Belt and Critical Minerals Belt. Airborne Surveys are done. Documents on request. Partner may do due diligence and after drilling can earn up to 80% interest in the claims. Email?turmacmact@msn.com or call Cell: (520)709-0601

    Porcupine Creek Information - click or double-click for larger view
    Valdez Mining District - Added 5/15/19.?Roosevelt Lake Area 13 claims for 1720 Acres. Active mining adjacent to claims. Several test runs through a high banker show $20 to $30 a yard. Mostly virgin ground.?Windy Creek Canyon, a few miles to the South. 13 claims for 640 acres. I have found gold and silver in good quantities. $15 to $40 a yard on tests.?All virgin ground.?The claims can be driven to in the summer. 4wd preferred, but not necessary. Prefer to be sold as blocks, but individual claim sales may be negotiated. ?Contact Claude at 907-394-2552 or email at akclaude2009@yahoo.com
    Petersville Area - Added 5/15/19.?Four forty acre claims located near Poorman and Cottonwood creeks. Road access. Two creeks drain into Cottonwood. Have info of area and geologist report. Asking 150K motivated to sell, serious inquires only. Contact Michele Stevens 907-345-9655 or email: goldengirl@petersvillemining.com website: http://www.petersvillemining.com Thank you for looking.?
    Valdez Mining District - Added 5/15/19.?Roosevelt Lake Area 13 claims for 1720 Acres. Active mining adjacent to claims. Several test runs through a high banker show $20 to $30 a yard. Mostly virgin ground.?Windy Creek Canyon, a few miles to the South. 13 claims for 640 acres. I have found gold and silver in good quantities. $15 to $40 a yard on tests.?All virgin ground.?The claims can be driven to in the summer. 4wd preferred, but not necessary. Prefer to be sold as blocks, but individual claim sales may be negotiated. ?Contact Claude at 907-394-2552 or email at akclaude2009@yahoo.com
    Petersville Area?- Updated 5/15/19.?Six State of Alaska mining leases totaling 2,690 acres. State of Alaska Mining Leases are a 20-year lease with the State of Alaska which I own the lease and the lease has 14 years remaining and are renewable. Also available are 25 forty-acre claims with 6 buildings and 3 airstrips. Located in historic and present Petersville/Yentna Mining District area, that has seasonal road access to all claims and leases. Located in Talkeetna C-2 Quadrangle north of the Peters Hills and all above tree line on Cottonwood, Poorman, Pass, Willow, Little Writer, and Peters Creeks where very limited mining of present alluvium has occurred. Drill logs, sampling, and certified geophysical information are available. Owner would like to see the property brought to commercial production. Prices have been dropped and owner is motivated to sell. Leases can be subdivided and sold as smaller leases if need be. Serious inquiries only. For more information contact Michele Stevens @ 907-345-9655, website: http://www.petersvillemining.com?or email:??goldengirl@petersvillemining.com Thank you for looking.?
    Valdez Creek - Added 4/24/19.?I have 40 acres in the upper Valdez creek valley near Tenas lake. Active mining on both sides of claim. $35,000 obo. ?I also have 600 plus acres on Gold creek across the hwy from Valdez creek. Shallow bedrock. Surrounding area claimed by large mining corp. Easy atv access but last few miles of road need repaired to drive a pickup in. Very good potential for commercial mining. I need to sell it. Only $50,000. I also own 240 acres of hard rock claims on top of Gold Hill. Make me an offer on it. Call 907-768-1137 I am gone often so leave message and I'll call ya back.?
    Manley Hot Springs - Added 2/23/19.?Alaska placer mine for sale 50 state claims located on Little Boulder Creek, Salt Creek, Trail Creek and West Fork 30 miles from Manley Hot Springs, AK on Tofty Road.?Can access claims by road ?some older equipment and camp.? 83 yrs young time to sell . ?email miningwild@gmail.com
    Fortymile River - Added 1/24/19.?Fortymile River mining lease for sale. Includes 10 claims, campsite with 2 storage sheds, an 8” & 6” suction dredge, 22’ riverboat for springtime hauling gear and a new 1652 Lund jon boat located 17 miles down river from the lower bridge.

    Fortymile River Mining Lease area
    Rental fees to state are only 375.00 a year for all 10 claims since it is a lease. ADL 588388 asking 40,000.00 obo. Call Royce at 907-317-0335
    Fortymile River - Added 9/30/18. I have nine claims I want to sell for?$3000.00 each. Also have a brand new Keene 8 inch suction dredge, and a new 6 inch dredge. A full camp site with everything you need from tents to wood burning stoves, showers, gold pans, etc. Call and make me an offer I?can't refuse for the whole package together, or may sell separate. 941-416-8839. Don.?
    Fortymile River?- Added 6/12/18. North fork of the Fortymile River, there are 8 river bottom gold claims for sale at?$2500.00 each. Want to sell together if possible.

    Fortymile claims, camp, and equipment
    Approx. 9 miles upriver from the North fork bridge. Accessible by boat or hovercraft. Gold average size is 20 mesh with a couple of pickers each day. Average 2-3 grams of gold per hour with a 6" dredge. Gravel bar avg. 2-1/2' of overburden down to bedrock to over on the river channel side is bedrock outcropping. Call 907-227-3850 or?lowrielp@aol.com
    Babe & Vault Creek?- Updated 9/30/18.?For Lease.?We have 440 acres containing almost 2 miles of virgin permafrost placer ground for lease 13 miles N. of Fairbanks. Babe and upper Vault Creek drain a gold rich belt that extends from Ester Dome NE to the Ft. Knox mine. Lower Vault Creek was extensively drift mined in the early 1900’s and was a major producer. One small drift operation was located on Babe Ck. but no production records have been found. There are several old prospect shafts on both creeks that indicate gold values at a MINIMUM of 1oz/30 yds of gravel. One such shaft was cleaned out and taken to bed rock which was at roughly 65’. I recently put down a 6’x6’ shaft and hit bed rock at 60’. Pay gravel is approximately 10’ in thickness. This mining season I’ll be cross drifting the valley to better determine the values to expect both up and downstream. Any operation undertaking the mining of these claims needs to not be deterred by significant overburden which varies from at least 30’ to 70’. An extensive drilling program would be needed. The history of lower Vault shows 1/3 of the gold recovered was 1 penny weight or better. There is good indication that the width of the pay could easily be 150’ to 200’ with the richest pay streaks being around 50’. The two creeks combined typically run enough water to supply a washing operation especially if ponded. There is a large spring that adds significantly to the water available. Contact: Kurt Blumberg e-mail:?flintgd@aol.com?or phone: 303-507-9502 for additional information.
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    Fairbanks Area?- Updated 10/2/18. Thirteen gold, silver and antimony claims. Accessible by highway and adjacent to the historic Nordale mine. Located below Cleary Summit in Fairbanks area (picture below).

    Claims were recorded in early 1920's with only a single corporation. These are placer and hard rock claims. Aging stockholders wish to sell. Contact Patrice Gapen at 307-631-0601 in Mountain Time or email?flypatr@yahoo.com
    Cooper Landing?- Added 5/8/18. 160 acre gold claim. Four 40 acre claims all connected. Good gold, easy access dedicated road and good camping area, good water.

    Cooper Landing claims and gold
    There is a creek running through the claims. Claims are located in Cooper Landing, Alaska 70 miles south of Anchorage.?$190,000 obo?email?barnesminingempire@gmail.com
    Coldfoot Area?- Added 4/11/18. 500+ acres placer gold mining claims, 17 miles south of Coldfoot with road access. Comes with drill logs along the Middle Fork of the Koyukuk river. You just have to go get the gold.?$145,000 or best offer. Mining equipment on site for sale (see below), if needed. For more information e-mail?kkdeill@gmail.com
    Mining equipment for sale near Coldfoot: double deck 5' x 14' wash plant, 320 and 235B excavators, D9G and D8H dozers, 966C loader, 55KW and 20KW gen sets, box trailers, tools and supplies. For pricing e-mail?ddkeill@gmail.com
    Alfred Creek (behind Sheep Mountain)?- Updated 7/3/18. Mining camp for sale on Alfred Creek near Sheep Mountain 123 miles from Anchorage. Over 2,400 acres in sixty State of Alaska mining claims. Mining camp is 12 miles off Glenn Highway (mile 123) and has road drivable by truck or 4 wheeler in the summer and snow machine in the winter. There is also a 2000 foot airstrip at camp. Six buildings include a heated main house with kitchen, bedroom, shower with hot water on demand, and storage area. Caretaker's cabin has a heated kitchen and bedroom. Also has modern outhouse, tool shed, an old miner's cabin and shelter.

    Alfred Creek camp
    Equipment includes a 6x6 truck, a 5 ton army cargo truck, 6x6 duce and half fuel truck, 6x6 duce and half cargo. All you need is heavy equipment, Mining records for '09 available. Water rights and exploration records available on most claims. Ideal business for suction dredging, metal detection work, panning, high banking or recreational use. Great area for hunting for moose, caribou, sheep, wolf and fox. Price reduced to $300,000 for package. For more details contact Ed DeWitt (907) 563-1822 or Cell(907)227-0801. email: eds@ak.net
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    Platinum, AK?- Updated 10/2/18. We have approximate 2000 offshore acres of State of Alaska mining claims available. Research: USGS, USBM and Thomas Oommen PhD. Geologist completed 2 studies,?one in 2006?and?one in 2008. Goodnews Mining Co. recovered 650,000 ounces in a 41 year time frame with a dragline and a bucket line dredge within a 6.5 mile stretch of the Salmon River. We are offering six (6) - 40 acre claims and eleven (11) - 160 acre claims, which total 2000 acres of State of Alaska offshore mining claims.?Asking $15,000 US dollars per 40 acre claim, $50,000 US dollars per 160 acre claim, OR $250,000 US dollars for all claims listed above.?Please reply to this ad via email at?GoldenMooseMining@gmail.com
    Placer Gold in Alaska?- Updated 10/1/18. On five miles of river claims. Gold grades average of 18 large samples is $44 per cubic yard at the grass roots, huge volume of gravel. Airstrip, trails, professionally surveyed and sampled claims with mineral report. Historic mining, but 99% unmined. Adequate water, water rights and cabin included. Complete buyout preferred.?Asking $2,500,000. Contact: Jim Halloran?augeojim@yahoo.com
    Valdez Creek / Grogg Creek?- Added 1/21/18. Selling 720 acres / 18 claims (40-acre claims) of state of Alaska placer mining claims. Along the east bank of the Susitna River, the claims are located on Valdez Creek. Creek is a historic gold bearing location and a leading producer. All the claims are state of Alaska claims, they are not patented. In the 80’s Valdez Creek (Cambior) became the largest placer gold operation in North America for about 10 years and in the best year it produced over 100,000 ounces of raw gold. The claims are about 212 miles from Anchorage at the confluence of Grogg Creek and Valdez Creek, in the Talkeetna Mining District. The area is reached by vehicles via the Denali Highway which connects Paxson on the east with Cantwell on the west. At about Mile 79 (measured from Cantwell) a gravel road heads north along the east bank Susitna River and goes through the old mining camp of Denali and up in back of White Creek and on the confluence of Valdez Creek and Grogg Creek. 4 miles up from Cambior Mine. You can drive to the claims with a 4x4 or 4-wheeler in the summer.
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    Valdez Creek claims and goldThese claims have huge potential. No mining equipment on site. Placer gold exploration permits. Great area for hunting caribou, sheep, wolf and fox. (Mile 69 Denali Hwy) At $450/oz. gold samples assay up to $15.00 a yard. (Reference sample, 1885, Mike Balen / Jerry Hannio U.S. Bureau of Mines). Excellent ore values. 0.0369 fine ounces per cubic yard of fine grained and flakey gold. Ft Knox ADL No. 539731 Downstream Cambior company’s, A channel, was a 15-foot-thick pay stream that ran 10 ounces per cubic yard.?Asking $200,000?- the claims will not be sold separately. Contact Peter if interested or with questions. Email:?indigoenterprises@gmail.com? Call: 206-501-6379
    Falls Creek?- Updated 10/1/18. I have three claims for sale in the Cache Creek Basin (Dutch Hills). They are on upper Falls Creek. I have held them since the late nineties. I am getting a little long in the tooth now and hope someone will be interested! The asking price is $12,500 for one, $10,000 each for two ($20,000 for two) and a great deal, $9000 each for three ($27,000 for three). Please e-mail me with questions / or interest?Niallix@aol.com?with the word CLAIM in the subject line.
    Kougarok River?- Updated 10/1/18. Seward Peninsula, approximately 100 miles North of Nome. 8.5 miles of continuous Alaskan State claims on the Kougarok river. 36 forty acre claims, all claims have the river running through them with several very interesting benches . We've prospected these claims over the last 8 seasons using a suction dredge w/ several paystreaks located (98% virgin to suction dredging). Three cabins on the downstream claim (2 miles from end of road), remote ( claims start at 2 miles from end of road and extend upstream for 8.5 miles), ATV, cat trail access.

    Kougarok River claims
    We found quite a bit of coarse gold on the lower claims, up to 7 oz nugget with gold running up into the bench from the river. This bench is roughly 35 acres and has an old timers cabin on it which I think they only built a cabin to mine rich ground. The upper claims have a paystreak of smaller gold that extends for at least a couple of miles (we haven't fully determined just how far this extends but have got as high as 2ozs/6 hr dredging session). There is an old cabin that could be fixed up or moved closer to the claims in the upper area. Downstream from there about 3 miles there's a large bench and a terrific campsite on the river. The bench carries colors and heavies (looks to me like an ancient channel). On the lower claims we found a nugget paystreak that probably extends 300' or more (we've established the upper end of this paystreak, then 200' down stream is where we found the 7oz nugget and at that time we covered the downstream ground with tailings so we know that the paystreak extends downstream, possibly for several hundred yards. All the claims are Alaskan State claims which means less problems... no BLM & the Kougarok river doesn't have salmon. Our Bottom line for the whole group of claims is 60K ?or ?we could break up the claims and if so we'd ask ?60K (bottom 10 claims), and the other 26 claims starting at $2500/claim respectively...the top 6 claims w/ the established paystreak I'd ask $22,000 if sold separately. ?If you purchased the whole 36 claims the price is roughly $1600/claim (which is a very good deal for I see several 40 acre claims in the general area for 40K or more per claim). I can't over emphasis the fact that we've prospected up there for the last 8 seasons...we know where we didn't hit any gold...we know where we hit some gold but not enough to pay with our 6" dredge... we know where there are existing paystreaks.... we know hidden trails for access.... we know of 4 separate benches that we've panned gold on.....and can give advice as to camping etc ... all this information is very valuable and should be taken into consideration. (most of the claims I see advertised don't have much positive information available). GPS coordinates : downstream boundary is 65.4589N, 164.6878W and upstream extends to 65.5671N, 164.7390W....ADL # 554358 thru 554390 plus 705584 and two other claims .... Fineness of the gold is 90.5 to 91%.......Age forces sale.....Contact: Jim at 530 626 8753 (10am to 5pm Mon thru Sat) or Jan at 360 427 5367 ..... email jansiks@yahoo.com
    Kenai Gold Claims?- Updated 10/1/18. Fifteen 40-acre state claims in two groups of placer ground with great access and off the road parking. All the claims would be great for suction dredging and high banking. Some of the claims have enough low bench ground for heavy equipment operations. They have not ever been mined to any significant degree. They have been held for decades in speculation, but they have a mining history. Hope-Sunrise Mining District. Good gold on every claim. No equipment and no permafrost.?Thirteen thousand dollars per claim or a better rate on groups of claims.?Sold in two or more claim groups only. About 70 highway miles from Anchorage. Contact:?augeojim@yahoo.com?for more information.
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  • Steve Herschbach
    These are reviews on metal detecting and prospecting equipment I have personally used over the years. In the last 45?years I have used a lot of metal detectors and prospecting gear! A lot of items are not made any longer but may be found used. In each instance my goal is to provide details and commentary not found anywhere else. If you see information here that is in error or wish to add something email me here with details.
    For more user reviews of metal detectors visit the new?Metal Detector Database. Do not miss Steve's Guide to Gold Nugget Detectors for honest opinions on gold nugget detectors updated on a regular basis. Visit the Detector Prospector Forums for expert advice. User Guides & Catalogs here.

    Fists Full of Gold - Perhaps the best prospecting book available! Fisher CZ Models - Some old favorites. Fisher CZX - Speculative new detector model.... Fisher F19 - General purpose VLF detector with prospecting mode. Fisher F75 - Flagship VLF model with prospecting mode. Fisher Gold Bug 2 - Dedicated VLF prospecting detector, extremely hot on small gold. Fisher Gold Bug Pro - Excellent value general purpose VLF prospecting detector. Fisher Manta - New pulse induction beach detector in the works at First Texas. Garrett AT Gold - Excellent value waterproof VLF prospecting detector. Garrett ATX - High performance pulse induction beach and prospecting detector. Garrett Infinium LS - Pulse induction beach and prospecting detector. Minelab Equinox 800 - General purpose detector with prospecting mode. Minelab Eureka Gold - Dedicated VLF prospecting detector, three selectable frequencies. Minelab Gold Monster 1000 - Dedicated VLF prospecting detector, extremely hot on small gold. Minelab GP 3000 - High performance pulse induction prospecting detector. Minelab GPX 4500 - High performance pulse induction prospecting detector. Minelab GPX 5000 - High performance pulse induction prospecting detector. Minelab GPZ 7000 - New high performance professional prospecting detector. Minelab SDC 2300 - Pulse induction prospecting detector, extremely hot on small gold. Minelab X-Terra 705 Gold - General purpose detector with prospecting mode. Nokta/Makro AU Gold Finder - Dedicated VLF prospecting detector, extremely hot on small gold. Nokta/Makro FORS Gold - General purpose VLF detector with prospecting mode. Nokta/Makro FORS Gold Plus - Excellent value VLF prospecting detector. Nokta/Makro Gold Kruzer - General purpose waterproof gold prospecting detector. Nokta/Makro Gold Racer - General purpose gold prospecting detector. Nokta/Makro Impact - Flagship?VLF detector with prospecting mode. Nokta/Makro Racer - General purpose detector with prospecting mode. Teknetics T2 - Flagship?VLF detector with prospecting mode. Tesoro Lobo SuperTRAQ - General purpose VLF prospecting detector. White's GMT - Dedicated VLF prospecting detector, very hot on small gold. White's GMZ - Dedicated VLF prospecting detector, hot on small gold. White's Goldmaster 24K - Dedicated VLF prospecting detector, extremely hot on small gold. White's MXT - General purpose VLF detector with prospecting mode. White's MX Sport - General purpose waterproof VLF detector with prospecting mode. White's TDI - Pulse induction beach and prospecting detector. White's V3i - Flagship VLF model with prospecting mode. XP DEUS V5 - Flagship VLF model with prospecting mode. XP ORX - New model from XP with an emphasis on gold prospecting. Comparison Reviews
    Garrett ATX vs Minelab GPX 5000 Waterproof Pulse Induction Detectors Compared For more user reviews of metal detectors visit the new?Metal Detector Database.
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  • Steve Herschbach
    This is my latest "Nugget Detector Guide", now published for over fifteen years, updated May 2020?with some of the latest model information. Each model has a short description, followed by a very PERSONAL OPINION. Copyright 2002-2020?Herschbach Enterprises - Please do not reuse or repost without my express permission.
    This is offered as a simple guide for those wanting a general comparison of the various nugget detectors available new with warranty, along with some kind of real opinion about them. That's all it is, folks, so take it or leave it for what it is worth. It's just that listing specs is of little help to people, and so I take my best stab at providing some guidance for those newer to detecting. These are only my opinions based on my experience with various detectors over the years. While I do have a lot of experience, I must throw in the caveat that I have not used all detectors under all conditions. What may be considered a good detector at one location may not be so good at another location due to differences in ground mineralization and the gold itself. Detector performance is site specific and so your mileage may vary. Never forget that when reading comparisons on the internet.
    Although many detectors sold today can potentially find gold nuggets, I've chosen to only list current models from major manufacturers that are sold and marketed primarily as prospecting detectors or that at least have a specific prospecting mode. I no longer list general purpose VLF detectors running under 18?khz because they are just too common and that being the case they offer nothing special to the potential gold prospector.?If you are interested in other general purpose detectors that might make good prospecting machine but are not listed here, look at my more comprehensive reviews list. Many discontinued prospecting detectors are also listed there.
    The list below has over twenty models listed and still may be too much for some people. In recognition of this I have made my best shot at picking three possible options I am calling?Steve's Picks. Click the link to jump there at the end of this page.

    Various popular VLF gold nugget prospecting metal detectors
    Please, if you own one of these detectors, and I call it like I see it, don't take offense. Any nugget detector made will find gold in capable hands, and the owner is far more important than the detector model. I'll put a good operator with almost any detector on this list up against a novice with whatever is deemed "best" and bet on the experienced operator every time. The person using the detector finds the gold. The detector is actually one of the less important factors in nugget detecting success or failure.
    A quick note to those who know nothing about these machines. These are metal detectors. There is no such thing as a "gold only" detector. These detectors will also find lead, copper, aluminum, and other metals. These units are best used to look for relatively larger pieces of gold at relatively shallow depths. Concentrations of gold dust are not detectable. Some of these units can hit gold that weighs as little as a grain (480 grains per ounce) or less but only at an inch or two. Only the larger nuggets can be found at depths exceeding a foot. Only world class nuggets weighing many ounces can be detected at over two feet. The vast majority of nuggets found are found at inches, not feet.?About Long Range Locators (LRLs)
    WARNING ON COUNTERFEIT DETECTORS - The market for nugget detectors far outsells coin and relic detectors worldwide, with huge sales in third world countries. This has made many of the models below very popular with counterfeiters. Here are some?Fisher?and?Minelab?examples. If you shop these models there are two simple rules. First, you are safe if you stick with approved dealers. Second, if the price seems too good to be true, beware! All legitimate dealers have a limit on how low they can advertise, the Minimum Advertised Price (MAP). Review prices at the approved dealer list, and if you find the detector advertised as new at a significantly lower price by somebody not on the list, the odds are very high you are looking at a counterfeit detector. Legitimate dealers are prohibited from advertising?at those kind of prices, and a price too good to be true is your number one warning you are about to be ripped off.
    The detectors are listed in order based on the lowest price normally advertised on the internet as of the date below.
    Steve's Guide to Gold Nugget Detectors - Updated May 2020
    Fisher F19 ($449, 19 kHz) - This detector is a?later, more advanced version of the Fisher Gold Bug Pro (see below), with added?features. There is an excellent threshold based all metal mode plus a dual tone discrimination mode. The F19 has both ground grab and manual ground balance, plus adjustable tone break, just like the Gold Bug Pro. Extra features are added to enhance the coin, relic, and jewelry capability, such as notch discrimination with adjustable notch width, volume control, separate ferrous tone volume, and a LCD meter backlight. These extra features may even find use while gold prospecting. The Fisher F19 can use any Gold Bug compatible coils plus those made for the Teknetics G2 series, providing for a huge number of possible accessory coils. This detector can be had with several stock coil options, including a 7" x 11" DD coil, or 5" x 10" DD coil.?Weight including a single 9V battery is 2.6?lbs
    Steve's Opinion - First Texas, the manufacturer of Bounty Hunter, Fisher, and Teknetics metal detectors, sells quite a few identical or near identical metal detectors under different brand names and model names. Due to oddities in their marketing scheme, some more powerful models are often available at lower prices than other less capable models. Currently the 19 kHz Gold Bug name carries a premium price, while other identical or more capable models sold under other names can often be had for less money. That is currently the case with the?19 kHz Fisher F19 models and the identical Bounty Hunter Time Ranger Pro model. The bottom line is this. If you can find a Fisher F19 with 5" x 10" elliptical coil for under $500 at a legitimate dealer (see counterfeit note above) it is easily my current recommendation for an extremely capable entry level VLF nugget detector with general purpose capabilities. I recommend this detector over the Fisher Gold Bug and Gold Bug Pro models below, not only because of the extra capability, but because it can be had stock with the 5" x 10" DD coil, the best general nugget hunting coil for the FT 19 kHz series. It can only be had as an accessory coil on the Gold Bug models, driving their out of?pocket cost even higher. A Steve's Pick. If you want a real deluxe set of extra coin and jewelry detecting features, see the equally capable Minelab X-Terra 705 below for only $50 more.
    Fisher Gold Bug ($449, 19 kHz) - Not to be confused with the Gold Bug from the 1980's, this new model runs hotter than that old model, and offers full LCD target identification. The target ID makes the Gold Bug good for more than just nugget hunting, and it finds favor also with jewelry and relic hunters. This model normally comes with a 5" round DD coil to enhance the sensitivity to small gold but other stock coil options are available. The Gold Bug features an easy to use ground balance "Grab" function. Do not confuse this detector with the Gold Bug Pro (see below), a nearly identical detector that adds a manual ground balance control.Weight including a single 9V battery is 2.5 lbs. Many accessory coils are available for the Gold Bug.
    Steve's Opinion - It used to be that this basic 19 kHz model was desirable for it's low?price. Now, you can get the Fisher F19 above with a better coil and far more capability for the same price. Pass.
    Minelab X-Terra 705 Gold ($499, 3, 7.5, 18.75 kHz) – This detector has a unique design feature. The standard unit comes with a 5" x 10" DD 18.75 kHz coil. Accessory coils are available not only at 18.75 kHz, but also at 3 kHz and 7.55 kHz. You can literally change the frequency of the detector by changing the coil! The X-Terra 705 has a large number of features and operating modes making it suitable for almost any type of metal detecting, be it for coins, jewelry, relics, or gold nuggets. Weight including four AA batteries 2.9 lbs. Over ten accessory coils are available for the X-Terra 705 (Minelab, Coiltek).
    Steve's Opinion - I like the X-Terra 705 very much indeed. It has a very powerful all-metal Prospecting Mode. The X-Terra 705 offers both ground tracking and manual ground balance; I like having both options. I particularly like its very compact and lightweight design. What really sets the X-Terra 705 apart however is all its other features. The X-Terra 705 is a good choice for somebody who wants all the coin and jewelry detecting options important to urban detectorists. It has discrimination and tone options equaling far more expensive detectors. This is the machine for somebody who really wants all the features a top end detector offers and still have a good prospecting detector. 2020?Note - a new lower internet price of $499 (down from $699) makes this detector an alternative to the Fisher F19 above. For $50 more the X-Terra adds quite a few extra bells and whistles for the coin, jewelry, and relic hunter, especially in the realm of target tone id options. It is likely this detector will be discontinued by Minelab when current stocks run low, replaced by the new Vanquish coin detectors.
    ?
    Nokta/Makro Gold Racer ($509, 56 kHz) -? The Gold Racer is based on the original Racer model released in February 2015. The Gold Racer at 56 kHz was unique when released in having all the features normally associated with coin and relic detectors yet it's running at a very high nugget detecting frequency. This makes it more of a general purpose detector than a dedicated nugget detector. The Gold Racer comes with a 10" x 5" DD coil and has three accessory coil options. The weight including four AA batteries is 3.0 lbs.
    Steve's Opinion - I like the Nokta/Makro Gold Racer as it really is something new instead of just another mid-frequency do-it-all detector. The compact lightweight design appeals to me as does the high frequency sensitivity to small gold nuggets. It is the only machine in it's class that can run a large (15" x 13.5" DD) high frequency coil and as well as having a concentric coil option. Best of all it offers a full range of discrimination features not seen in other high frequency nugget detectors, all at a very aggressive price. Worth a very close look, especially if a large coil option is important.

    Fisher Gold Bug Pro ($549, 19 kHz) - Essentially the same as the Gold Bug above with the addition of manual ground balance. The target ID makes the Gold Bug Pro good for more than just nugget hunting, and it will find favor with jewelry and relic hunters. The manual ground balance gives expert operators the control they desire to get the best depth possible. This unit normally comes with a 5" round DD coil to enhance the sensitivity to small gold but other standard coil packages are available. Weight including a single 9V battery is 2.5 lbs. Many accessory coils are available for the Gold Bug Pro.?
    Steve's Opinion - The Pro is the final version in this series which saw several early variations including the Gold Bug above. It is a excellent choice for prospecting, relic, or jewelry detecting and does fine as a coin detector also. However, you are now paying a premium for the Gold Bug name, and the more capable Fisher F19 at the top of this list can be had in a better configuration at a lower price. Unless you just want the name, pass.
    Nokta/Makro Gold Kruzer ($636, 61 kHz) - Nokta/Makro started shipping?the new Gold Kruzer model?in June 2018. The Nokta/Makro Gold Kruzer is a variant of the Nokta/Makro Gold Racer above that has been boosted to 61 kHz from 56 kHz and put in a waterproof housing good to 5 meters (16.4 ft). The Gold Kruzer comes with a 10" x 5" concentric coil and a 4" x 7.5" DD coil. The weight including LiPo batteries is 3.0 lbs. There are four coils available for the Gold Kruzer.
    Steve's Opinion - The Nokta/Makro Gold Racer has been one of my favorite detectors because until recently there was nothing running in this frequency class that had full target id and other options normally seen only in coin detectors. The Gold Kruzer takes it all to the next step by being waterproof in excess of ten feet. There are no other detectors running at a frequency this high that are fully submersible with built in wireless capability and therefore?this detector may find favor with freshwater jewelry hunters as well as prospectors. The Gold Kruzer is worth keeping an eye on and is a better value than it appears at first glance due to the dual coil packaging. Note 2020: the Nokta/Makro Gold Kruzer package has been reduced from $749 to $636, dropping it just under the AT Gold in price. This aggressive price drop?in a waterproof 61 kHz dual coil package makes this model very hard to resist. I would not even consider a Garrett AT Gold personally compared to the Gold Kruzer at this price.
    ?
    Garrett AT Gold ($638, 18 kHz) - A totally new concept in metal detecting from Garrett Electronics. This full featured detector has everything you would expect from a dry land detector - LCD display, full control set and functions, speaker, interchangeable coils, and light weight. But it is submersible to 10 feet! Even the speaker is waterproof. Note that the unit itself may be submerged but if you want to put your head underwater you will need optional submersible headphones. Weight including a four AA batteries is 3 lbs. The stock coil is a 5" x 8" DD elliptical. Many accessory coils are available for the AT Gold.
    Steve's Opinion - The Garrett AT Gold was an innovative option when it was introduced, and the only waterproof nugget detector option at the time. The industry has caught up and even surpassed Garrett now and unless the AT Gold comes down in price it's hard to recommend for somebody interested primarily in a nugget detecting VLF. Only for Garrett fans really, otherwise newer models like the Nokta/Makro Gold Kruzer above are better deals.
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    Nokta/Makro AU Gold Finder ($679, 56 kHz) - The Nokta/Makro AU Gold Finder came out in 2016 and is basically a Nokta/Makro Gold Racer (see above) put into a different housing that emphasizes simple knob controls. The housing is IP56 dust and water resistant. The AU Gold Finder comes with a 10" x 5" DD coil plus a 5" round DD coil. The weight including four AA batteries is 3.1 lbs.
    Steve's Opinion - The AU Gold Finder is an interesting option in that it specifically is made to look and handle more like older style analog detectors for those who prefer such things. The simple knob design is intuitive and putting everything in a sealed box allows the detector to be chest or hip mounted, a rarity in today's detectors. Since the AU Gold Finder is basically a Nokta/Makro Gold Racer in a different housing?they can actually share the same coils. However, the coils that come with the AU Gold Finder have much longer cables to allow for use when the control box is hip or chest mounted. Gold Racer coils work but the shorter cables only make them suitable for use on the Gold Finder when it is rod mounted. Bottom line, a good prospecting detector and a good value with two coils, overlooked by many due to a very limited number of dealers stocking the unit.
    ?
    Fisher Gold Bug 2 ($699, 71 kHz) – The Gold Bug 2 is the highest frequency detector on the market, for extreme sensitivity to the smallest gold nuggets. In moderate to low mineral conditions, no detector will pick up a smaller nugget than the Gold Bug 2, especially if it is paired with its 6.5” accessory coil. The lightweight and tough hip mountable design is great for rough terrain. The Gold Bug 2 is a manual ground balance unit. Weight including two 9V batteries 2.9 lbs. The unit can be purchased stock with either the 10" elliptical coil or 6.5" elliptical coil, or both. Two accessory coils are available for the Gold Bug 2.
    Steve's Opinion - An excellent example of a niche machine that excels at one task. The Gold Bug 2 has extreme sensitivity to small gold combined with what I feel is the best physical design of any nugget detector on the market. Lightweight, tough, and convertible from rod mount to chest or hip mount. Its main drawback is that it gets poor depth on larger gold in mineralized ground. As in poorer than any other nugget detector listed here. It is also a harder for beginners to learn than newer units since it has no automatic ground tracking or ground "grab" options. The GMT above is a better choice for all around performance. But if mastered and paired with the small 6" coil no detector will hit smaller gold. The Gold Bug 2 has a particularly effective "Iron ID" mode that not only rejects iron targets but many iron hot rocks. I consider my Gold Bug 2 my "go to" detector if I simply want to find some gold. I can hit tiny pieces weighing less than 1/10th grain with the 6" coil.

    White’s GMT ($729, 48 kHz) – The GMT has exceptional small gold capabilities with its high 48 kHz frequency. The GMT features automatic ground tracking for ease of operation, and also has manual ground balance for those wishing full control of their detector. The GMT also has one of the most advanced iron discrimination systems available in a dedicated nugget detector. Weight including eight AA batteries 3.9 lbs. Four accessory coils are available for the GMT.
    Steve's Opinion - The GMT features both automatic ground tracking or fully adjustable manual ground balance, your choice and a real plus on the GMT. One of the most common problems people have with detectors is in getting the ground balance right. There are also areas where wildly varying ground mineralization makes constant manual retuning a chore. The automatic ground balance on the GMT lets a beginner get up and running quickly. It offers the pro the ability to deal with rapidly varying ground. And yet for those times when you need manual ground balance to really tweak the detector, the GMT has it also. The GMT always tracks the ground conditions, even when in manual mode, and so while in manual adjusting the ground balance can be as simple as hitting the "Grab" button. The LCD based "iron probability" readout offers more subtle iron discrimination than the all or nothing audio id on other units. The GMT rivals the Gold Bug 2 on small gold, and clearly outperforms it for depth on larger gold in highly mineralized ground. If you are looking for a combination of superb small gold capability combined with good depth on larger gold plus ease of operation the GMT is an excellent choice.

    White's Goldmaster 24K ($729, 48 kHz) - The new White's Goldmaster 24K was announced for 2018 and started shipping to customers in September of that year. This followup to the popular White's GMT adds increased power, advanced ground tracking (patent pending), target id information and more. The Goldmaster 24K comes with the 6" x 10" DD search coil. Weight including eight AA batteries 3.5?lbs. Three?accessory coils are?available for the Goldmaster 24K.
    Steve's Opinion - One of the newest models on this list, this is a very hot detector, with voltage to the coil boosted by 54% over the GMT. This makes the Goldmaster 24K a little bit more sensitive to small gold than the GMT while the new XGB ground tracking system helps offset the extra sensitivity with multi-point ground balancing. I ran the Goldmaster 24K and particularly liked how it felt and performed with the 6" round concentric coil. Other reviews are appearing now and?all are very positive - looks like White's has a winner!? This is now my preferred high frequency VLF nugget detector due to its ease of operation combined with advanced control options, and a great coil selection.?A Steve's Pick.
    XP ORX ($748, 14, 28, 56, 80 kHz) - XP has just released this new product for general sales.?The new XP ORX emphasizes gold prospecting and coin detecting in the promotional material. The XP ORX?appears to be a version of the "Africa only" Depar DPR 600 made for sales in Europe, the U.S., and elsewhere. The Orx has been refined from that early effort by the addition of the ability to use the new X35 coils.
    Steve's Opinion - With XP switching the old low frequency coil models over to the newer X35 coil series it appears that XP intends for the ORX to be the high frequency option with an emphasis on gold prospecting, and for a lower price than the Deus model. The coils are the same as those used by the Deus and I expect the performance on gold nuggets to be identical also to what the Deus offers with the high frequency coil option. This machine is available with wired headphones for $649 and well worth considering at that price, but I have listed it here with the popular wireless headphone option. I think the ORX is a great little nugget hunter personally (I love the compact design), but it seems to be overlooked my most serious prospectors and getting more attention as a low cost alternative to the XP Deus for coin and relic detecting.

    Minelab Gold Monster 1000 ($849, 45 kHz) – The Minelab Gold Monster 1000 came out in 2017. The model is replaces the Minelab Eureka Gold as a much lighter and less expensive detector. Main features are a hot 45 kHz frequency combined with automatic ground tracking and even an automatic sensitivity option. The Minelab Gold Monster comes with both 10" elliptical and 5" round DD coil plus rechargeable and standard AA battery packs (AA batteries not included).
    Steve's Opinion - I have been a little surprised how I took to the Gold Monster 1000. This has been based more on its grab and go simplicity than anything else. It has?excellent sensitivity to small gold and and dual coil package for a good?price.?The main issue for beginners is to resist over-driving the sensitivity which can lead to false signals. The big?selling point for the Gold Monster is the minimum control set and almost totally automatic operation. Some professionals however may chafe at the lack of audio threshold and the very same limited amount of control?that appeal to others. I’m personally do not like the?screw together rod at all, a stand out flaw for an otherwise excellent detector.
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    Minelab Equinox 800 ($899, 5, 10, 15, 20, 40 kHz plus Multifrequency) – The Minelab Equinox 800 has just been released and is only now becoming available in quantity. It includes a dedicated Gold Mode with up to 40 kHz operation and offers the first true multifrequency nugget detecting capability.
    Steve's Opinion - The Minelab Equinox 800 and the Equinox 600 to a lesser degree are proving to have some major sensitivity to gold nuggets in mineralized ground. I have been very impressed with what I have been able to make the Equinox do as a gold prospecting detector. The stock 11" coil is less than ideal for nugget detecting, but the new 6" coil is proving to be very stable and have extreme sensitivity to very small gold. I am not recommending all prospectors run out and get an Equinox. It is primarily a general purpose detector. However, if you want a capable general purpose detector that is quite capable of finding gold nuggets, the Minelab Equinox has serious possibilities. It's actually my go to machine for VLF gold prospecting at this time as I enjoy exploring all the options the machine offers.?Equinox nugget detecting tips.

    White's TDI SL ($1049, Pulse) – This detector from White's Electronics is a variation on the original TDI. Nugget detecting was a main focus of its design although it has other uses as well. Weight including battery is only 3.5 lbs. with the 12" coil. It uses industry standard coils. Over 100 accessory coils are available for the TDI SL (White's, Minelab, Coiltek, Nugget Finder, Razorback)! And more coils are being released every year. See the new TDI Special Edition variant.
    Steve's Opinion - ?The TDI SL has a unique set of features and performance at a very reasonable price point. The fact that it is compatible with the large base of existing Minelab PI prospecting coils is a huge plus. I honestly like the TDI SL a lot because of its light weight and aggressively low price but I wish it had more horsepower. In moderate to low mineral ground I think the White's GMT is the better option, with the TDI SL only really showing its stuff under severe ground conditions. Be aware that a good VLF may serve as well for less money than a PI detector - see the note below.

    A note on PI detectors. It is important to note the TDI is a pulse induction (PI) unit, like the Garrett ATX and the Minelabs below. This means it has rudimentary discrimination compared to VLF units. It is best to view PI units as all-metal, dig-it-all detectors. They do have some limited discrimination capability, but it is not why you get a PI unit. Depth in extreme mineralized ground and an ability to ignore difficult hot rocks are the selling points. In addition, some PI units have poor sensitivity to small gold compared to VLF units, and so someone with less expensive VLF unit can run circles around someone with a PI unit at low mineral locations. I tend to consider PI units as elephant hunting guns, best used when larger nuggets are known to be lurking in an area. New PI detectors are challenging my perception in that regard however. Some areas demand PI detectors regardless of gold size due to extreme mineralization and/or hot rocks. My basic recommendation for most people is use a VLF when you can, and use a PI when you have to. You first clue to when this will be is when you basically can't get your VLF to work properly due to ground and hot rock conditions. In much of the US a good VLF is perfectly suitable and often a better choice than a PI. However the western US and most of Australia has places where a PI is an absolute necessity.

    XP DEUS ($1299, 4 kHz, 8 kHz, 12 kHz, 18 kHz plus 14 kHz, 30 kHz, 55 kHz, 80 kHz) – The XP DEUS is a new detector from France that is seeing rapid adoption in the U.S. It can be operated in any one of four different frequencies and has perhaps the fastest recovery time between targets of any detector made today. The DEUS is noted for being completely wireless with the coil independent from the control units and headphones. The detector is exceptionally light at only 2.2 lbs. and with the wireless control box dismounted the rod and coil only weighs 1.96 lbs. The stock coil is a 9" DD round. Two accessory coils are available. Several versions of the detector are available from $1069.00 to $1899.00. Price listed here is for DEUS with FX-02 wired headphones + remote + 9" coil.
    Steve's Opinion - The XP DEUS has a dedicated prospecting mode called the Gold Field Program. It is a fantastic piece of technology, programmable for many detecting tasks, and groundbreaking in its use of wireless technology. The XP DEUS is currently regarded as one of the best detectors available for working exceptionally trashy locations and for this reason it may be good from extracting gold nuggets around old camp sites and other locations littered with nails and other junk. The extreme light weight certainly appeals. The Version 4 update added improvements to the Gold Field program and the option of two additional High Frequency (HF) coils running at 14 kHz, 30 kHz, 55 kHz, and 80 kHz. The DEUS outfitted with one of these new coils will give the best VLF prospecting detectors a run for the money. Unfortunately adding one of these coils also adds about $400 to the price above. The DEUS is not a detector I would buy specifically for gold prospecting - If all you want is a prospecting detector there are other VLF options for far less money. If you want a DEUS anyway however (for coin, jewelry, and relic detecting) and want to use the new HF coils to search for gold, rest assured the DEUS can do the job as a VLF prospecting detector. My real hope has been for a version sold specifically as a gold prospecting detector with the HF coil as stock at a much lower price - see the new XP ORX above.

    Garrett ATX ($2120, Pulse) - This new model takes the AT series to a new level with pulse induction. It features an extremely compact military grade housing submersible to 10 feet. Even the built-in speaker is waterproof. Note that the unit itself may be submerged but if you want to put your head underwater you will need optional submersible headphones. The ATX features a unique collapsible/folding design for stowing and backpacking. It is powered by eight AA batteries. The ATX comes with a newly designed 10" x 12" DD coil and weighs 6.9 lbs. Two accessory coils are available.
    Steve's Opinion - The ATX is a great addition to my working collection of detectors. The ATX is a very versatile detector and fully capable of almost any task a person wants to use it for. The ATX is a superior beach detector and one of the better pulse induction nugget detectors currently available. It is sensitive to gold nuggets weighing as little as 0.1 gram and yet has very respectable depth on larger gold nuggets. I think the ATX has a performance edge over the TDI SL but at twice the price and twice the weight it has not set the prospecting world on fire. The main problem is the heavy waterproof housing driving the price up so high that in Australia the ATX does not compare favorably to the much more popular Minelab models. In the U.S. it has settled into being most used for beach and relic detecting. Mine goes along as a backup for my GPZ 7000 while gold prospecting but it actually sees more use with me as a beach detector. I have tried for years to convince Garrett to make a light weight less expensive dry land version of the ATX but so far to no avail. At this point unless having a waterproof detector is critical to your needs, spending the little more money to get a Minelab GPX 4500 makes more sense.
    Minelab GPX 4500 ($2699, Pulse) - This Pulse Induction (PI) unit essentially ignores ground mineralization and most hot rocks. The GPX 4500 is designed specifically for nugget detecting and so it has many adjustments for mineralized ground not available on other PI detectors. The 4500 weighs 5.3 lbs. not including the harness mounted battery, which weighs another 1.7 lbs. The detector comes with both an 11" round DD coil and 15" x 12" mono coil. Over 100 accessory coils are available for the GPX 5000 (Minelab, Coiltek, Nugget Finder)! And more coils are being released every year.
    Steve's Opinion - Minelab just reintroduced the GPX 4500, a prior model to the GPX 5000 below. Currently it is being offered with two coils for only $2699 which represents a fantastic amount of performance for less than half the price of the GPX 5000. The main thing lacking on the GPX 4500 that the GPX 5000 offers is the Fine Gold timing. This is a setting that eliminates the most troublesome hot rocks and ground while still getting most of the gold. You also get the Salt Gold and Coin/Relic timings plus the Enhanced timing has been improved on the 5000. However, $3000 more for these differences is a bit much and in my opinion the GPX 4500 now represents the best "bang-for-the-buck" option available for those wanting a powerful pulse induction prospecting detector. 2020 note: it appears Minelab is discontinuing the GPX 4500. There are available still and Minelab still lists them on their website as a current model, but dealers are saying it's going away. That would remove an great value choice for prospectors and I for one hate to see it happen. Grab one while you still can.
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    Minelab SDC 2300 ($3799, Pulse) - This model is unique as Minelabs first waterproof pulse induction metal detector. A key feature is that the detector is physically packaged in the proven F3 Compact military housing that is waterproof to ten feet and folds down into an incredibly compact package only 15.7" long and weighing 5.7 pounds including four C cell batteries.
    Steve's Opinion - I have used the Minelab SDC 2300 for a over a year now and I must say I am very impressed. The waterproof compact design is perfect for hardcore backpack style prospecting. The main thing however is that the SDC 2300 comes as close to VLF type performance on small gold as you can get while being almost impervious to the ground mineralization and hot rock issues that plague said VLF detectors. In fact, the SDC 2300 will find gold nuggets smaller than most good VLF detectors can detect even under favorable conditions. The SDC 2300 is also one of the simplest detectors to use and master on the market. The main caveat is that the detector is optimized for small gold with the hardwired coil and so other ground balancing PI detectors are a better option for large nuggets at depth. It is also nearly twice the price of the Garrett ATX above and so you are paying quite a premium for a little better performance on small gold. Still, for novices in hot ground that can afford the price, the SDC 2300 is almost impossible to beat if the goal is just to go find some gold, any gold at all.

    Minelab GPX 5000 ($3999, Pulse) - This Pulse Induction (PI) unit essentially ignores ground mineralization and most hot rocks. The GPX 5000 is designed specifically for nugget detecting and so it has many adjustments for mineralized ground not available on other PI detectors. The GPX 5000 is the culmination of over 10 years of innovation in pulse induction technology. The GPX weighs 5.3 lbs. not including the harness mounted battery, which weighs another 1.7 lbs. The detector comes with both an 11" round mono coil and 11" round DD coil. Over 100 accessory coils are available for the GPX 5000 (Minelab, Coiltek, Nugget Finder)! And more coils are being released every year.
    Steve's Opinion - It is simple. The Minelab GPX 5000 is the safe choice for best all around pulse induction gold prospecting performance. It has been out for many years, is well proven and reliable, and has a vast selection of coils and accessories to cover almost any situation. Despite the new GPZ 7000 below this is still the unit most people should be looking at though the even lower price GPX 4500 above should also be considered. A Steve's Pick.

    Minelab GPZ 7000 ($7999, ZVT) - The new Zero Voltage Transmission technology from Minelab promises to take gold prospecting to the next level. The new platform represents a break from the past SD/GP/GPX series in more ways than one, with a new weatherproof housing design based on the Minelab CTX 3030. The GPZ 7000 weighs 7.32 lbs. and comes with a waterproof 14" x 13" coil. There is one accessory coil available at this time.
    Steve's Opinion - The GPZ 7000 represents the future and I am convinced it offers a performance edge when compared to the earlier Minelab PI detectors. For this reason I have sold my GPX 5000 and switched fully to the GPZ 7000. The only weakness the machine seems to have at this time is an inability to deal quietly with wet saturated salt or alkali ground and certain volcanic hot rocks. That said I have not regretted for one second selling my GPX 5000 due to the overall advantage I feel I get with the GPZ 7000 in my ground and on my gold.

    If I can offer one final word of advice, it would be to pay particular attention to what experienced nugget hunters are using in any particular region. Do not assume you are going to outsmart them and find some model they have not already tried and set aside as less than optimum. Serious prospectors in any particular location will end up focusing on certain units that do the job. In areas of extreme mineralization this is usually a PI detector. In areas with less mineralization and lots of ferrous trash VLF units often are preferred. If you can discover what models the locals prefer it will give you a head start in knowing what to use yourself. Above all, whatever detector you finally choose, dedicate yourself to mastering it. It takes at least 100 hours of detecting to become proficient with a detector model. Any less, and you are still practicing. Knowing your detector well is more important than what particular model of nugget detector you own.
    Steve's Picks
    I decided to add something new to this page. The list above has grown so much over the years that even it is really too long for some people. So I have decided to just pick my favorites in the three essential categories that I think every new prospector should consider:
    1. The super hot VLF
    2. The medium frequency VLF
    3. The ground balancing pulse induction (GBPI).
    The explanation that follows gives some rationale for my picks, but a huge factor is a good proven history in the field by many people under a wide range of conditions. Just being the latest new thing does not do it for me as much as being tried and true when it comes to my recommendations for others. It is very wise to wait about 6 months to a year after any new detector is introduced to see how others fare with it in the field before committing your hard won dollars. Widespread dealer support and service options are also very important.
    Finally, and this is most important. This short list is aimed at beginners. I assume the more knowledgeable folks don't need this kind of guidance. I am specifically assuming the reader is a first time buyer looking for the best value in a proven nugget detector. Along with that I lean towards simplicity of operation and focus on the task at hand as opposed to overwhelming control options. So these machines are not a list of the three "best" machines but instead a list of what I think are solid options I would advise a person new to nugget detecting to consider.
    Category one is the hot induction balance detector for finding tiny gold nuggets no other detector can find. These would be detectors running over 30 kHz. Contenders are the Fisher Gold Bug 2 at 71 kHz, Makro Gold Racer at 56 kHz, Makro Gold Kruzer at 61 kHz, Minelab Gold Monster at 45 kHz, and White's GMT and Goldmaster 24K at 48 kHz. This is a tough one because so many of these detectors get the job done so well. My pick at this time is the new White's Goldmaster 24K. This new detector is easy for beginners but has room to grow with features professionals will appreciate, good ergonomics, and a great coil selection. I have one myself, so there you go.
    Category two is the medium frequency VLF. The main goal here is to have a detector that can punch deeper on large nuggets in bad ground than the super hot VLF detectors and do a good job of discriminating out ferrous trash. These would be the good detectors for working trashy campsites and tailing piles. They are also the detector for a person wanting more versatility for other detecting tasks than offered by the dedicated high frequency detectors. The potential contenders list is very long - see above. My pick at this point in time is the Fisher F19, a more capable Gold Bug Pro variant available stock with the 5" x 10" DD coil, and at a lower price now than the Gold Bugs, which carry a higher price simple due to the name. An excellent alternative for those wanting a truly deluxe do-it-all machine with all the bells and whistles is the Minelab X-Terra 705 for just $50 more.
    Category three is a detector to handle the worst hot rocks and bad ground. For many serious prospectors this will be the primary unit, the one to find gold with. The obvious choice here (for me anyway)?is a Minelab GPX 5000. This detector is the culmination of years of development by Minelab and it has incredible aftermarket support in the form of coils and other accessories. For those with the money and a desire to be on the cutting edge of new technology the Minelab GPZ 7000 is an alternative but the GPX 5000 is a safer choice for a wider range of conditions. Those who want a GPX 5000 and who can't quite afford it should instead consider the GPX 4500 at half the price. If a GPX is too intimidating, then the Minelab SDC 2300 may be just the ticket.
    Steve's Short List of The Prospecting Metal Detectors May 2020
    1. White's Goldmaster 24K?(category 1, small gold sniper)
    2. Fisher F19?(category 2, basic general purpose prospecting)
    3. Minelab GPX 5000 (category 3, ground balancing pulse induction)
    In my opinion a well equipped prospector needs two detectors. One a high power GBPI for most nugget detecting and a VLF for trashy areas and as a backup. A GPX 5000 plus a F19?or Goldmaster 24K would be a hard combination to beat.
    A special note of the Minelab GPZ 7000. This detector represents a fourth category, the "hybrid" detector that uses continuous wave technology like a VLF but also employing time constants much like a PI detector. These detectors act like a "Super VLF" with the ability to detect gold missed by GBPI detectors but with the ability to get depths on par or exceeding those previously seen only with GBPI detectors.?I hesitate recommending it over the GPX 5000 to just anyone because of the high price tag, weight, and lack of coil options. The GPX 5000 in my opinion is the safer choice for overall versatility, at half the price.
    So there you are. Hopefully this helps some people out. I can be found daily on the Detector Prospector Forums and would be pleased to answer any questions you have on metal detecting and prospecting. Also check out Steve's Guide to Metal Detecting for Gold Nuggets.
    Sincerely,
    ~ Steve Herschbach
    Steve's Mining Journal
    Copyright ? 2002 - 2020?Herschbach Enterprises - Please do not reuse or repost without my express permission.
    ?

  • Steve Herschbach
    I have added two new sections to the website that cross link to each other. The first is a Metal Detector Database with User Reviews. Most current name brand metal detectors are listed with basic specs like price, weight, water resistance, etc. You can sort the listing by these basic specifications and you can leave your own review of each detector. Discontinued models are now being added. The new area is accessed in the menu under "Reviews"
    The second area is a revamped Downloads Area. Various manufacturer catalogs are collected there for historical reference to models, specifications and prices. More importantly, each detector in the Reviews database has it's user guide listed for download plus any other pertinent documents like sales flyers.
    Basically the Reviews area links to the Downloads area and vice versa. This is all under construction still and will be for some time as regards discontinued models. I am adding cross links and new listings almost daily. Hopefully this will allow people easier access to information and manuals now scattered across the internet. Please do your part by leaving reviews of any metal detectors you have used. Thanks!


  • Steve Herschbach
    I recently treated myself to a metal detecting holiday to the area around Colchester, England. This was a reprise to a trip I made to the UK in 2010?in search of Celtic gold. Gold was not in the equation for that trip, but I did find the oldest coins and artifacts I have ever found.... as in 2000 years older than anything I have found before!
    Colchester has history reaching back into prehistoric times, and is generally acknowledged as the location of Britain's first city. Celtic tribes were active in the area, leaving behind many Celtic gold coins to be found by modern day detectorists. The Romans were also very active in the area, as were other invaders, leading to finds from many cultures across the centuries.
    I made a return visit to Colchester in 2018, this time relying heavily on the new Minelab Equinox metal detector as my detector of choice. I also had the opportunity to use the new Minelab Equinox 15" x 12" DD coil while on this trip. Not only did I have a very successful trip, but I got to observe other great finds made by the other detectorists in the group. All in all this was a very exciting metal detecting experience that I enjoyed thoroughly. The links below outline both my own experiences and the same trip told from the perspective of another person on the same adventure.
    Steve's 2018 UK Adventure?by Steve Herschbach
    My UK Trip .... Double Ancient Gold!?by Ill Digger

    Steve Herschbach finds ancient UK gold!
    ?

  • Steve Herschbach

    XP Orx

    By Steve Herschbach, in Steve's Reviews,

    The XP metal detector company has announced a new model for late 2018 called the XP ORX. This new model appears to be a refined version of the XP manufactured Depar DPR 600. The DPR 600 was made to take advantage of the African gold rush by offering a model designed primarily as a gold prospecting detector with other uses taking a back seat. I personally think the Depar DPR 600 was used as a proving ground for the new high frequency (HF) coils while also offering an opportunity to fine tune the Gold Field program. My expectation all along is that XP would eventually release a similar model for sale outside of Africa. It looks like after almost two years that new refined version of the DPR 600 is available for purchase as the XP ORX.
    This introduction is so new that information at this time is limited - everything here is subject to change as new details emerge. For now what we know for sure is that the XP Orx will be available in two configurations. The versions are basically the same, with a wired headphone version for 700 Euro, and a wireless headphone version for 800 Euro. U.S. pricing is unknown at this time but $799 and $899 is probably in the ballpark. You can choose either the 9" round HF coil or 5" x 9.5" elliptical HF coil. There is no exact word on availability yet, but presumably we will be seeing this model available for purchase in early 2019.

    XP ORX gold prospecting metal detector
    It is possible hints about the new XP Orx can be gleaned by reading the DPR 600 User Manual. One main difference is in the User Modes. The DPR 600 and XP Orx both have four preset programs plus two user custom program slots for saved programs. The programs on the DPR 600 are designated as 1. General 2. Large Gold 3. Fine Gold 4. Iron Discriminate. The XP Orx is designed for a bit wider appeal, and so it looks like the General and Iron Disc modes have been recast as coin hunting modes. The modes on the XP Orx are 1. Gold 2.?Fine Gold 3. Coin Fast 4. Coin Deep
    ORX Key features:
    HF coil technology (21 Frequencies ranging from 13 to 81kHz). Extreme sensitivity to small targets with high frequency 50kHz and 81 kHz. 4 factory programs: Gold Prospecting (x2) – Coins and Relic (x2), + 2 user. Trusted XP fast wireless technology: Coil – Remote – Headphones – MI-6. The all new “WS Audio?” compact wireless headphone receiver. Re designed ultra-light Telescopic “S” stem. The lightest machine on the market at only 770grs (remote hip mounted). Easy to operate with a user-friendly interface. Wireless connectivity to the MI-6 pinpointer + advanced remote settings. Lithium batteries, giving up to around 20 hours of detecting. Easy to charge with any certified USB charger or via computer (XP USB charger optional only) Available with a choice of HF coils – 22cm (9") Round or 24/13cm (9.5"x5") Elliptical. Compatible with the X35 coil range (22, 28, 34/28cm). Software Update (remote control via USB cable). Go terrain mobile app compatible (coming 2019). 5-year warranty – Made in France. Affordable price – Suggested maximum retail price: 699€ including taxes – 799€ including taxes with wireless headphone (WSA). Note that the upper armrest area of the rod has been redesigned and is different than the existing Deus rod assembly.

    XP ORX Controls & Settings
    ORX settings:
    99 levels of sensitivity 21 frequencies (13 kHz to 81 kHz). 99 levels of discrimination + 5 levels of IAR Discrimination in Gold programs. 20 levels of Threshold. 4 levels of Reactivity. Iron Tone with Pitch audio (ON/OFF) Ground balance: manual adjustment from 60 to 90 or automatic (fast grab). Salt mode ground rejection: 00-25 4 factory + 2 user programs. Target ID/ Iron probability. Pinpoint function with target zoom. Go-Terrain compatible (smartphone app coming soon).? ads by Google...


    XP ORX MI-6 Compatibility
    Advanced remote settings when the ORX is paired with the MI-6 pinpointer:
    50 levels of sensitivity Audio tone from 120 Hz to 1582 Hz 2 audio modes: PITCH or PULSE 3 factory + 1 user program Recover a lost MI-6 (even when switched off) Target zoom screen Battery life indicator I don't think there is much mystery here except for how many people will opt for this new model versus the new X35 coil based Deus models. In my opinion by extending the top end frequency of the new X35 coils to 28 khz has inadvertently removed some of the demand for this higher frequency version. Small gold sensitivity gains over 30 khz are quite minimal and with the extra features the Deus offers many people may continue to prefer it as their detecting solution. A lot may boil down to the price difference between a 9"?round X35 Deus package and the 9" round HF Orx package.
    No matter what I am very confident this new high frequency XP model will do very well for gold prospecting. I do not expect performance to be any different than that I observed while testing the XP Deus with elliptical HF coil on small gold.
    XP Orx Data & Reviews
    XP Orx Owner's Manual
    Forum Threads Tagged "xp orx"
    XP Metal Detector Forum
    XP ORX Technical Specifications*Internet Priceestimate $649 wired headphones or $795 wireless headphonesTechnologyInduction Balance (IB)Frequency14, 28, 56 kHz (round 9") or 14, 28, 70 kHz (elliptical)Autotune Mode(s)Multiple "Reactivity" SettingsGround RejectionGrab, Manual, TrackingSoil AdjustNoDiscriminationVariable, Visual ID, Tone ID, NotchVolume ControlYesThreshold ControlYesTone AdjustYesAudio BoostYesFrequency OffsetYesPinpoint ModeYesAudio Output1/8" headphone socket & speaker, wireless headphonesHip MountYesStandard Coil(s)9" round DD or 9.5" elliptical DDOptional Search Coilsnew X35 coil seriesBatteryBuilt In RechargeableOperating Time20 hoursWeight2.0 lbsAdditional TechnologyWireless coils, control box, headphones; firmware updates via internetNotesProbably based on "Africa Only" Depar DPR 600*Notes on Technical Specifications - Detailed notes about the specifications listed in this chart.
    ?

  • Steve Herschbach
    White's MXT Engineering Guide
    David E. Johnson, engineering consultant
    This Engineering Guide is written to provide dealers and customers greater insight into what kind of product the MXT is, from an engineering perspective. It does not attempt to provide complete information on the features and use of the MXT: for that, please consult the MXT user's manual.
    A BIT OF HISTORY
    In January 1998, White's decided to develop a true multipurpose metal detector, with the kind of sensitivity it takes to be a real gold prospecting machine, and with computerized ground tracking for ease of use. White's in-house engineering staff was tied up on the project which eventually became the DFX. Therefore, in February White's asked me if I might be interested in taking on a new protect. I had a good track record on gold machines so it seemed like a good fit. I agreed.
    A month later at a dealer seminar in Sacramento, California, Jimmy Sierra announced the project, and said if the engineer didn't deliver, the engineer would have to go into hiding in Mexico. I was sitting in the back.
    We ran into one problem after another along the way. Jimmy, good chap that he is, didn't sic the thugs on me, though there were periods he was frustrated enough that the thought must have run through his mind. Although the project took longer than we expected we got two products out of it - the GMT and the MXT.
    The first major hurdle was to get the basic circuit and software system running, with a first class ground tracking system. The system architecture was totally new, not a revision of the existing Goldmasters. In early spring of 1999 an ugly prototype was up and swinging, and Larry Sallee became involved in field-testing. By April the ground tracking system was working so well that since that time very few changes have been needed. At that point we knew we had a solid foundation, so work began on the display, discrimination and target ID features.

    During the fall of 1999, we decided to tackle the problem of desert heat head-on. A lot of gold prospecting is done in desert heat in full sun. I set up a crude but effective, thermal engineering laboratory, measuring the temperatures reached inside housings of various configurations and colors in full sun. Then began the task of finding an LCD, which would handle the heat. Because the LCD display is an important feature of the MXT, we revisited the whole issue of display. The manufacturers of LCD display had expanded their product offerings. We found a larger one, and changed the mechanical design of the MXT to accommodate it. A FSTN 0160 F was selected, (there are more to choose from nowadays, so we used a bigger one than the GMT in the MXT.)
    In early 2000, White's decided to bring out a new Goldmaster based on the work that had already been done, while development of the multipurpose unit continued. So we modified a prototype to work with the Goldmaster search coil at about 50 kHz, and you know the rest of that story - the GMT "tracking Goldmaster" was introduced in early spring of 2001.

    As work continued on what eventually came to be called the "MXT", we spent a lot of time on the discrimination and target ID system. There are many different ways to do discrimination and ID, each with its own advantages and disadvantages, which aren't always known until you've had the thing in the field being tested for a while. A lot of work got thrown out as we found deficiencies in what had already been done, and discovered ways to improve things. As the project got closer to production, more people became involved with it, and offered their own ideas to improve it. The reason the MXT is as good as it is, is because of that long process of field-testing and revisions.
    While the MXT was still under development, the DFX was introduced. The MXT design was then revised to run at about 14 kHz in order to take advantage of the DFX loops.
    When it was finally time to call it "good" in June 2002, the MXT went into production quickly and smoothly.
    CIRCUIT DESIGN
    The circuitry of the MXT is almost identical to the GMT, which has already been on the market for a year and a half and has proven to be rock-solid.
    The GMT's circuitry broke a lot of new ground. It uses a reactive impedance transformation network to boost transmitter voltage for higher sensitivity. It uses an active transmitter regulator to keep transmitter voltage constant even when the search coil is moved over black sand that would blow an unregulated machine off the air. The differentiator-filter circuits usually found in metal detectors are eliminated. Those functions are now done in software, which is made possible by the use of a high-precision 16-bit A/D converter used in a way that makes it equivalent to 17 1/2 bits. All the controls are digitized, their function actually performed via software rather than in circuitry. The audio system is temperature compensated in software to eliminate threshold drift.
    For the MXT, we chose an operating frequency of 13.889 kHz. This is high enough to give good sensitivity to gold, low enough to give good target ID on typical coin, trash, and relic targets, electrically compatible with search coils derived from the DFX and halfway in between power line harmonics to minimize electrical interference.
    SOFTWARE
    The MXT uses a Microchip PIC 16C76 micro controller, chosen for its low power consumption and its set of features, which was a good match for this application. The software that runs in this chip is based on that in the GMT, but almost all of it is new or has major revisions, except the device drivers and the ground tracking system. Much of the new software is for target ID and discrimination, features that were not present in the GMT. Even the iron probability and VSAT systems in the MXT are new, despite their apparent similarity to the GMT.
    The MXT/GMT does as much of the signal processing as possible in software rather than in circuitry, using what we call "low-speed DSP architecture". The demodulated signals are digitized, and processed and analyzed in software. Control positions are also digitized and made part of the data in software. The desired audio signal is computed, and then converted back to voltage using a 12-bit D/A converter. The circuit board communicates with the LCD and trigger switch in the "pod" via a custom-designed serial link.
    In the MXT the filters, differentiators, and sample-and-hold functions are performed in software, not in circuitry. This eliminates the problems of channel mismatch and drift, which are often encountered in such circuits.
    The discrimination system is a second derivative ("two-filter'') design for quick response over a broad range of sweep speeds. The analysis system for determining what kind of target is present has special features which reduce interference from ground minerals, and which automatically scale target ID confidence according to the mineralization level.
    GROUND TRACKING SYSTEM
    The ground tracking system comprises two subsystems: a ground analysis engine, and a ground balancing system. The ground analysis engine continuously monitors incoming signals?to determine whether the signals probably represent ground, or may be something else such as metal targets or electrical interference.

    Signals, which seem to be ground only, are put into a data analysis subsystem, which analyzes the data for a number of variables. Then it can be determined what the balance point of the ground matrix is and how fast that balance point is changing. It'd be nice to describe all this in detail?but we'd rather not teach our competitors how to do it.
    The ground balance system does the actual balancing of the signals, doing in software somewhat the same job as a ground balance knob does on a manually balanced machine. When the TRAC toggle is in the "ground" or "salt" positions, the ground balancing system follows the output of the ground analysis engine. When the toggle is in the center "lock" position, the ground balance subsystem stops following the output of the ground analysis engine, which is still chugging away in the background continuing to gather ground data.
    The ground analysis engine can do a good job of telling the difference between ground matrix and anomalies such as hot rocks and metal targets. In order to tell the difference, it has to see matrix by itself during at least part of the sweep. When you're not in "lock", keep your sweeps broad, and don't loiter over the top of a target when checking it out. Otherwise the analysis engine may lose the ground matrix and start tracking into the target. However, if the target is strong enough to register on the VDI readout, the target ID system will tell the analysis engine to halt, allowing you to check the target without tracking into it. In all three programs, pulling the trigger to pinpoint a target also tells the ground analysis engine to halt. Some users will hunt with the tracking toggle in "lock", occasionally updating the ground balance by flipping into "ground" or "salt" momentarily when they start hearing too much ground noise.
    The resolution of the ground balancing system is 1 part in 4,000, and most of that resolution is concentrated in the range where high mineralization occurs. Therefore, the individual resolution steps are below audibility under all conditions.
    THE VSAT SYSTEM
    The VSAT system on the MXT is similar in a general way to the one on the GMT. The VSAT function is done entirely in software. Up to about 2/3 rotation, the SAT is of the conventional (first derivative or auto tune) kind, giving a "zip" sound on a nugget and a "boing" sound on a negative hot rock (cold rock).

    As you approach maximum rotation, the MXT goes into "HyperSAT". HyperSAT is a completely different type of SAT system with different sounds and target responses. The background threshold sound is a little rattier, but nuggets are crisper, the ground is quieter, and negative hot rocks vanish when you slow down your sweep. For all but the most experienced users whose ears are calibrated to hear every little nuance of a regular SAT signal, HyperSAT gives more effective depth in bad ground than normal SAT.
    THE DISCRIMINATION CONTROL
    The discrimination control does pretty much what you'd expect. Unlike some discriminators, when the control is at zero, there is no discrimination at all -?i.e., "true zero discrimination" - and all targets will be detected. Below about 2, the discrimination is based on a combination of both signal phase, and signal strength relative to the strength of ground mineralization. This feature allows the user to get good rejection of shallow iron with minimal loss of deeper targets.
    THE GAIN CONTROL
    The gain control knob controls two things at once: the preamp circuit gain, and the software gain. The following is a simplified explanation which is not technically correct in all its details, but will serve to give a general picture how the gain control works.
    As you advance the gain control from 1 to 10, the preamp circuit gain steps through five levels of gain: xl, x2, x4, x8, and x16. On most machines (depending on minor variations in search coil alignment) you can hear a momentary blip as the machine switches from one gain level to the next. The recommended preset (marked by the triangle) corresponds to a preamp gain of x8.
    In mild ground conditions where there is no electrical interference, you may want to advance the gain control into the crosshatched region. In this region, the signal data in software is multiplied by successively larger numbers, increasing the loudness of the signals. It is somewhat similar to the "audio boost" function found on some other models of metal detectors. It's particularly useful if you're using the speaker rather than headphones and there's a lot of noise from traffic or wind, or if you're demoing the machine to someone else.
    BASIC SENSITIVITY PERFORMANCE
    Since this is a multiple-purpose machine, a U.S. Nickel coin is the most appropriate standard test target. With the gain cranked up, and in the absence of electrical interference, a nickel will typically "air test" beyond a foot using the standard 95O search coil. Your actual "air test" distance will depend on your hearing, the sweep speed, what search coil is used, how much electrical interference is present, and how you have the controls set.

    In comparison to other machines in this price range, the MXT is extremely hot on low-conductivity items. On gold, it's right in there with the more popular gold machines, being especially hot on the larger, deeper nuggets. It will compete with all comers on low-conductivity , relics and on nickels. On high?conductivity coins such as quarters and silver dollars, it is still an excellent?performing machine, but there are several other products in the same league for sensitivity.
    GROUND TRACKING PERFORMANCE
    The ground tracking system is nearly identical to that in the GMT, which is widely regarded as one of the best tracking systems on the market. Compared to most other trackers, the MXT has superior resolution, tracks faster, "jumps" into new ground more quickly, has greater resistance to tracking into targets, and tracks over a wider range of soil conditions. The MXT allows tracking to be inhibited if desired.

    DISCRIMINATION PERFORMANCE
    All discriminator designs are compromises. Here's how the discriminator in the MXT stacks up against other machines.
    AIR TEST "DEPTH": generally well beyond 10 inches, because of high sensitivity, with effective discrimination to within 0-3 inches of the basic air sensitivity of the target. Most discriminators will discriminate in air to within 0-3 inches of the target air depth on most targets, but most don't have the sensitivity of the MXT.
    QUICKNESS & TARGET SEPARATION: among the best, because of medium-speed second derivative ("two-filters") design. Initial field reports indicate that the MXT's mixed-mode tone system gives indication of adjacent ferrous/nonferrous targets, superior to that obtainable through discrimination.
    IRON REJECTION: Because of its high sensitivity and a slight preference in the software for not losing questionable targets, it'll be a little chattier than some less sensitive machines. Reducing sensitivity by cutting back on gain, or by reducing the threshold control setting to minimum, will help quiet it down when necessary.

    DEPTH IN MINERALIZED GROUND: Although the MXT is a two-filter system, it incorporates special techniques which reduce ground interference and which reduce the "chopping & popping" which plague most other two-filter machines. This, together with its high basic sensitivity, makes it an excellent machine from the standpoint of discrimination depth.
    FAST SWEEPING: Many discriminators tend to lose good target signals, even shallow ones, when quickly sweeping the search coil. The MXT is tolerant of moderate search coil sweeps, that is to say good at both faster and slower search coil paces.
    SUMMARIZING: The MXT has the responsiveness and sensitivity of a first-rate 2 filter machine, combined with the discrimination accuracy of a first-rate 4-filter machine.
    TARGET I.D., ETC.
    With its small medium and large blocks on the target ID screen, the ID system in the MXT bears a superficial resemblance to the "Signagraph" of the Spectrum XLT.

    It should be realized that the traditional White's Signagraph system is typically (optionally) set to accumulate data over multiple passes over a target, and displays the accumulated average. The MXT displays fresh data on each pass and scales the size of the block according to how strong the signal was relative to the ground conditions on that specific pass over the target.
    The visual ID system on the?MXT is fast, easy to read, generally more accurate than the discriminator, and gives a visual indication (via block size) of how reliable the identification is. It is going to change the minds of many beeper enthusiasts who previously thought visual ID to be of little practical use outside typical coin shooting.
    CASCADE
    THE CASCADE OF EFFECTS OF GROUND BALANCE SETTING: In order to know what the ground balance setting is; flip momentarily to the gold program if you were in another mode.

    Electronic ferrite material and most "negative hot rocks" (cold rocks) will usually read in the 75-88 range. Most soils will read somewhat lower. Readings will almost never go below 25 except in salt or moist alkali soils. When readings indicate smaller numbers than 50 you may notice some reduction in sensitivity. Below 35, some rusty iron may give unpredictable responses. Below 25, iron objects may give unpredictable responses and/or may disappear entirely and the sound on nonferrous objects may become slightly more abrupt.
    MANY THANKS
    To Kenneth White and Alan Holcombe for having sufficient confidence in me to put food on my table through the good times and the rough times on this project. To Jimmy Sierra for having the patience to argue with me about all the stuff that needed arguing about, for being so passionate about the need for this product, and for being willing to compromise when that's what it took to keep the project moving. To Larry and Sue Sallee, for their personal hospitality and for field?testing prototypes. To Keith Zorger, Randy Smith, Mike Brighty who field-tested and helped develop the MXT. To Bob Canaday, for being such a competent technical/engineering liaison, doing a lot of not glorious but necessary work well and managing the project during its sometimes difficult phases. To Rick Maulding, for overseeing the project, for technical contributions to the discriminator and to the salt system, and for committing White's engineering department's finest minds to engineering review during the "slow SAT isn't hot enough" crisis, which led to a major system revision that made the whole machine better. To John Earle and Dan Geyer, for diligently hacking away at problems until they became non-problems. To Steve Howard and Pam Godell of White's. There were other people involved in this project whose contact was primarily or exclusively with White's and not with me. The risk of printing credits is that one may inadvertently omit a name that belongs there; so, if I missed someone whose name belongs on this list, I'm sorry, it was an unintentional oversight. - D.E.J.
    P/N 621-0468 published 8/2002 by?White's Electronics
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  • Steve Herschbach
    The Chisana area of Alaska was the site of the last major gold rush in Alaska in 1913. As a young man researching areas to look for gold I found a reference to this remote location in the Wrangell St. Elias Mountains. It is accessible only by air and for short periods of time each year. I started visiting this area in the early 1970's and then off and on again over the decades that followed.
    The area is high above treeline and frozen for most of the year. It was mined with simple shovel into sluice box type operations along the creeks followed up by hydraulic mining on bench deposits. The remote location,?lack of water, short season, and generally small area of the gold deposits meant this district never saw anything more complex than hydraulic mining operations. In later year operations have been confined to smaller scale hand operations plus gold dredging and metal detecting.
    I told a couple stories about this area as part of my?Steve's Mining Journal?but kept fairly low key about the location. This was mostly because the claim owners were not looking for publicity. However, the mine owners decided to sell a couple of their claims. They had?to advertise them to sell them. That in turn gave me the excuse to finally tell more about my visits to the place over the years, and to share the many photos I have of this rather unique part of Alaska.
    I am telling the tale as part of an on-going episodic thread on the Detector Prospector Forum - The Chisana Story?- check it out!

    Steve Herschbach with gold creviced from bedrock at Chisana, Alaska
    ?

  • Steve Herschbach
    This section focuses on gold prospecting for individuals and small time operators. Equipment used may include metal detectors, suction dredges, gold pans, and sluice boxes. You will find articles here to help you for both beginners and pros. There is location?information,??equipment reviews, and more.

    Steve's Mining Journal?- Real life gold prospecting and metal detecting stories spanning over 40 years.
    Gold Prospecting & Metal Detecting Guides?- Basic information to get you started.
    Recreational Mining Sites, Parks, Museums, etc.?- Locations available to the public to look for gold and other rocks & minerals.
    State Specific Information?- General gold locations, geology, and history.
    Mining Claims For Sale in Alaska?- Mining claims and leases in Alaska that are being offered for sale.
    Gold Prospecting & Metal Detecting Library?- Online books and other reference material about gold prospecting and metal detecting.
    Steve's Guide to Gold Nugget Detectors?- updated now for over 20?years, Steve gives honest opinions regarding various metal detectors past and present.
    Steve's Reviews?- Equipment reviews focused on metal detectors for gold prospecting, much more in depth than the previous summary.
    Detector Prospector Forums?- Forums on metal detecting for gold, gold panning, rocks & minerals, gold dredging, geology, plus coin, relic, jewelry, and meteorite detecting.
    Links To Other Websites?- Links to other websites and forums with relevant?information.
    Metal Detector Database -?Metal detector feature and specifications database with user reviews.
    ?

  • Steve Herschbach
    The White's Goldmaster 24K has been announced and has just started shipping to customers. The Goldmaster 24K is an alternative to the White's GMT updated for the 21st century, with advanced ground tracking technology and increased power.?XGB technology?is a patent-pending automatic ground balance system. It is purpose-built for operating a high-frequency VLF gold nugget detector in the worst ground conditions. Traditional VLF detectors struggle to balance rapidly changing ground mineralization. Historically this has been where Pulse Induction machines fared much better.
    With XGB technology, the Goldmaster 24k is able to track small changes in soil composition as well as longer-term shifts in both ground phase and strength. This allows it to operate in ground that traditional VLFs struggle in. Users have extended control over the range of XGB in the Goldmaster’s All-Metal mode. Simply enable Iron Cancel to expand the ground filter in moderate soils. In very challenging soil conditions, hold the Iron Cancel button and select the 2-bar setting for maximum performance in variable ground.
    New 9/12/18 -?Detailed Review Of White's New Goldmaster 24K

    White's Goldmaster 24K metal detector - new for 2018
    The new White's Goldmaster 24K also features a full backlit LCD target id screen and control suite. The potential target id is displayed on the screen whenever possible - the higher the number, the better the chance of a non-ferrous target. There is dual tone capability that reports a low tone for ferrous objects, and a high tone for all non-ferrous targets.
    White's Goldmaster 24K Features
    SENSITIVITY - Set the sensitivity at a level that does not result in false signals from the ground. Very strong ground may result in the symbol on screen and a loud sound - this means the sensitivity is too high. GROUND BALANCE - With the default setting, the detector will use XGB to automatically ground balance. Tap to lock the ground balance to the current setting. Tapping when the ground balance is locked will update the current ground setting to what is under the coil. GROUND SCAN - Hold to put the detector into Ground Scan mode. The top bar displays the ground strength and the two digit numbers display the ground type (phase). Useful for tracing paystreaks. IRON CANCEL - Tap to silence hot rocks, trash and mineral changes in both audio modes. Hold to select the Iron Cancel setting (1 bar is default). Note that this setting may decrease the detector’s sensitivity to very small gold, but is necessary in difficult ground conditions. VOLUME and THRESHOLD - Tap to adjust the volume with the up and down buttons. Hold to adjust the threshold with the up and down buttons (“th” displays on screen). Set these to a comfortable level for your hearing and preference. AUDIO MODE - With the displayed on screen, the detector is in “BEEP” audio mode (high tone = good target, low tone = bad target). The default setting (without on screen) is a traditional All-Metal audio mode with greater sensitivity to small targets. SAT - SAT can smooth out ground inconsistencies. Hold to adjust it (“Sa” displays on screen, 2 is the default setting). PINPOINT - Hold for non-motion pinpoint mode. In difficult ground this mode may be affected by mineralization. BACKLIGHT - Tap to enable the backlight (this reduces battery life). FREQUENCY SHIFT - Hold when turning the detector on to shift frequency (useful when there is EMI). Power off to save the selection. FACTORY RESET - Hold when turning the detector on to perform a factory reset. Not only does the new White's Goldmaster 24K features a new ground tracking system, but the gain has been boosted with an increase of voltage to the coil. From the Advanced Guide (link below):
    "When our engineers set out to build the GM24k, the goal was simple: improve the user’s chance to find gold without hurting their wallets. The obvious way to achieve this goal is increased sensitivity. The GM24k features a 54% increase in coil voltage over the GMT. You will see this in increased sensitivity to small nuggets. While testing this machine in Brazil, this was shown in a tiny, 0.4 grain crystalline nugget we found encased in quartz. In some cases this much power can be counter-productive if the ground is very challenging, so use it with caution! Even at lower gain settings the GM24k is an extremely “hot” machine on small gold and specimen nuggets."
    The new White's Goldmaster 24K comes with both rechargeable batteries and a holder for AA batteries. The GMK comes standard with the 6" x 10" DD search coil. Currently the is one accessory coil available, a 6" round concentric coil. Both a 14" x 8" DD and 6" x 4" DD coil are possible in the future but have yet to be offered for sale as of March 2019.

    White's Goldmaster 24K display and controls
    Here is a video released August 8, 2018 that goes over the basic features and operation of the Goldmaster 24K...
    Official White’s Goldmaster 24K Page
    White's Goldmaster 24K Quick Start Guide
    White's Goldmaster 24K Owner's Manual
    White's Goldmaster 24K Color Flyer
    White's Goldmaster 24K Advanced Ground Tracking Explained
    Detailed Review Of White's New Goldmaster 24K
    White's Goldmaster 24K & GMT Compared
    Forum threads tagged "whites 24k gmx"
    White’s Metal Detector Forum
    White's Goldmaster 24K Technical Specifications*Internet Price$729TechnologyInduction Balance (IB)Frequency48 kHzAutotune Mode(s)Variable Self Adjusting Threshold (V/SAT)Ground RejectionTracking & Fixed w/Grab function, Ground Balance OffsetSoil AdjustNoDiscriminationVisual & Audio Ferrous IDVolume ControlYesThreshold ControlYesTone AdjustNoAudio BoostYesFrequency OffsetYesPinpoint ModeYesAudio Output1/4" headphone socket & speaker (Headphones Included)Hip MountShaft Mount OnlyStandard Coil(s)6" x 10" DD Coil standardOptional Search Coils6" round concentric coilBatteryRechargeable NiMH plus Eight AA Pack IncludedOperating Time20 - 40 hoursWeight3.5 poundsAdditional TechnologyXGB Ground Tracking Technology, Ground Scan mode for tracing black sand deposits, Meter backlightNotesIP54 Rain & Dust Resistant*Notes on Technical Specifications?- Detailed notes about the specifications listed in this chart.
    ?
    From this thread:
    GOLDMASTER 24K WHITE'S?PAPER
    XGB - A New Way To Ground Balance
    The biggest challenge we face as electronic prospectors is highly mineralized ground. Simply increasing the gain on the current VLF platforms might help prospectors in very mild ground conditions, but what about more difficult areas with concentrations of black sand, maghemite, serpentine, or alkali salts?
    On a trip to Brazil we witnessed a combination of these conditions, with soil that ranged from red to black to purple, and exhibited a combination of ferrous and alkali properties within a 4 ft square section. We saw first-hand VLFs from each manufacturer fail to balance out the combination of minerals. Even the top-of-the-line pulse induction machines struggled in this area - machines which cost the garimpeiros (the local term for gold miners) several years’ wages.
    Our goal was simple: a nice even threshold in challenging ground conditions without giving up sensitivity. The theory is that the main battle most electronic prospectors fight is being able to discern a potential gold signal from ground noise. A smooth threshold would allow users to use more gain and increase their odds of finding small gold where it likes to hide - in mineralized ground.
    The issue with other VLF detectors on the market is that they were tracking a single ground balance point. When the ground type changes quickly, the machine gives off a false signal. For a user the result is ear fatigue, frustration, and less positive signals dug. One easy way to mask variable ground is implementing an auto-gain feature ?that automatically numbs the detector. This does not solve the issue, only hides it.
    The Goldmaster 24k’s XGB is a new automatic ground tracking system that works by tracking multiple ground points simultaneously and quickly. Where other VLF’s track one ground balance point, the Goldmaster 24k?tracks several, and can determine an optimal “ground window” based on ground history and strength. This is very useful in rapidly changing ground conditions, where other VLF machines may struggle to track the mineralization changes. Combine this with the speed at which the Goldmaster 24k is able to grab ground samples, and you have a superior ground balance system for a prospector’s VLF.

    XGB Ground Balance versus legacy methods
    With any automatic process, there are some concessions. Take vehicles for example - manual gearboxes are still preferred by car enthusiasts. That’s why we felt strongly about including a TracLock? ground option. When used with the Ground Grab, a locked ground balance setting allows users to set the ground balance in an area and lock it until they need ?to re-ground balance. For users after the tiniest bits of gold, this option allows for the maximum sensitivity to small signals.
    One technique we observed from field testers was allowing the XGB to automatically track, and ?then ?after getting a solid hit or finding a patch, locking the ground balance for target location and retrieval. For ?many users this combination will be the best of both worlds - the strength of XGB, but only when you need or want it.
    ?
    The net result of an overhauled automatic ground balance system is a VLF gold nugget detector that ?can ?be ? used ? in wider variety of ground conditions with a nice stable threshold. Operating a machine with a smooth threshold allows for a user’s ears to tune into those slight variations that just might be the next nugget. Our goal is that our customers are able to have success with the Goldmaster 24k in areas that other VLF’s struggle, and at a price that allows more people to get a taste of electronic prospecting.
    Tom Boykin
    White's Project Manager

    Gold nuggets found with new White's Goldmaster 24K - smallest under 1/10th grain
    ?

  • Jim Hemmingway
    Benchtesting Rocks & Minerals with an F75 Metal Detector
    Introduction
    From the earliest time when we were aware of our surroundings, most of us looked for pretty rocks. We wondered what interesting or valuable minerals might possibly comprise them. Now as adult hobbyists, I doubt if any of us hasn’t benchtested an interesting rock from curiosity, and wondered what actually produced the signal.?
    Although a sensitive benchtest usually has little in common with how marginally conductive rocks and minerals respond to metal detectors in the field due to ground effects, we can learn and become familiar with how rocks and minerals in our respective areas respond to metal detectors in a benchtest. A sensitive metal detector’s electromagnetic field penetrates rocks, usually generating either a positive or a negative signal in response to whatever material is in the rock. We can sometimes determine whether such signals should be investigated further, or whether worthless iron minerals produced them.?
    I’d generally describe my benchtest results as worthwhile and informative, but that notwithstanding, I look forward to doing a benchtest because I think it is an intriguing study on its own merit. That said, how do you conduct a benchtest? I’ll describe my methods and hopefully we’ll see what you think about it.

    Benchtest Requirements and Techniques
    Benchtesting ideally requires a visually displayed, fully calibrated, manually adjustable ground balance that covers the entire (soil) mineral range from salt to ferrite. As a minimum, the detector should feature a threshold-based true motion all-metal mode, and preferably an additional true non-motion all-metal mode for significantly improved sensitivity to borderline samples. Visual displays in either of the true all-metal modes are essential for target ID, Fe3O4 magnetic susceptibility and GB readouts.?
    I prefer a small (concentric) coil to promote detector stability and improve sensitivity to the rock sample, to ensure uniform sample exposure to the coil, and to minimize EMI (electromagnetic interference) especially if benchtesting at home. Elevate the sensitivity control as high as possible while maintaining reasonable detector stability such that you can clearly hear changes to the threshold.
    To check for a target ID, move the sample back and forth across the coil at a distance that produces the best signal but does not overload the coil. To determine ground balance and Fe3O4 readouts, advance the sample toward the coil, back and forth to within an inch or two (depending on sample size and signal strength) of the coil’s electrical sweetspot. Ensure your hand does not come within detection range of the coil to avoid creating false signals. If you extend your fingers to hold the sample, this is not an issue when testing larger samples. If necessary use a plastic or wood food holder that can firmly grasp small samples.

    Benchtests should be conducted utilizing a minimum of two widely diverse GB control adjustments. Initially I prefer the same GB control adjustment that is typically required to keep my detector ground-balanced to the substrates in my prospecting areas. It’s a personal preference that works for me. That particular GB control point (F75 / GB86) is more likely to improve any rock or mineral sample’s signal strength compared to using a more reduced (more conductive) GB compensation point.
    The next step is to use a dramatically reduced GB control adjustment (F75 / GB45) as suggested by Fisher Research Engineering. This setting ensures that (obviously weathered) oxidized samples do not generate a positive signal from any type of non-conductive iron mineral inclusions, particularly maghemite mineralization that may be present within such rocks. It follows that this second benchtest will, if anything, slightly subtract from the sample signal strength, particularly with low grade and otherwise marginally conductive samples, compared to the first step of the benchtest at GB86.?
    As a general rule, I do not recommend the F75 / GB45 compensation point for benchtesting (non-oxidized) mafic samples that are dominated by constituents such as common magnetite or other black minerals that normally support highly (non-conductive) elevated GB readouts. Such samples can produce strong negative threshold responses at the reduced GB compensation point. It will be difficult or impossible for the signal from a marginally conductive substance to successfully compete with those negative threshold signals. For non-oxidized samples Fisher Research Engineering suggests using F75 / GB65 rather than the F75 / GB45 compensation point, since obvious iron mineral oxidation should visually be absent from such samples.
    With the above discussion in mind, extremely fine-grained, unweathered magnetite that occurs in pyroclastic material (for example volcanic ash) can drop into the GB45 range, but it is extremely rare. Unweathered volcanics do frequently drop into the GB70's due to submicron magnetite, but the recommended F75 / GB65 compensation point will eliminate those positive signals.?

    The arsenopyrite sample depicted above is a good example of a commonplace mineral that we encounter in the silverfields of northeastern Ontario. Generally field examples could be described as marginally conductive and many are low-grade. A good many react with only a mild positive signal, and sometimes not at all to a benchtest depending on which GB compensation point is used.?
    The high-grade, solidly structured sample above produces a strong positive signal in either zero discrimination or true motion all-metal mode with the ground balance control adjusted to the GB compensation point required for our moderately high mineralized soils. As noted, that’s approximately F75 / GB86, although in the field, of course, it varies somewhat depending on location and coil type / size employed.?
    The response is not as strong as a similar size and shape metalliferous sample would produce, but it does generate a surprisingly strong benchtest signal that would be readily detectable in the field. Even with the GB control dramatically reduced to more conductive values (F75 / GB45), to ensure that any positive signals produced by non-conductive iron mineral inclusions should now only produce a negative threshold signal, it is no surprise that this (non-oxidized) specimen continues to generate a strong signal.?

    For those readers unfamiliar with detector responses to such minerals, the same general response scenario described above with arsenopyrite applies to other marginally conductive minerals such as galena, pyrrhotite and to a lesser extent even iron pyrites. Ordinary iron pyrites is generally innocuous, but maghemitized pyrite, pyrrhotite, and the copper sulfide ores, particularly bornite and chalcocite, can be a real nuisance in the field due to magnetic susceptibility, magnetic viscosity, and / or electrical conductivity, just depending on what minerals are involved.?
    Such variable responses from arsenopyrite and many other mineral and metalliferous examples clearly infer that signal strength and potential target ID depends on a sample’s physical and chemical characteristics, including the quantity of material within a given rock. These factors include structure, size, shape, purity (overall grade), and magnetic susceptible strength of iron mineral inclusions. Moreover, the VLF detector’s sensitivity, the GB compensation points employed, the coil type and size, and the sample profile presented to the coil further influence benchtest target signal strength and / or potential target ID readouts.?
    Incidentally, neither of my PI units will respond to the arsenopyrite sample depicted above, even with a TDI Pro equipped with a small round 5” mono coil, the GB control turned off, and a 10 usec pulse delay to deliver its most sensitive detection capability. That result is typical of most, but certainly not all sulfides and arsenides that occur in my areas. Higher grade and solidly structured pyrrhotite, an unwelcome nuisance iron sulfide, and collectible niccolite, a nickel arsenide, are commonplace mineral occurrences here that do respond strongly to PI units, although their respective VLF target ID ranges are quite different.?
    As a related but slight diversion, the photo below depicts a handsome example of the widely occurring mineral sphalerite. It forms in both sedimentary beds, and in low temperature ore veins. It is interesting to collectors because it possesses a dodecahedral cleavage which means that it breaks smoothly in twelve directions, and it is usually triboluminescent, meaning that it gives off a flash of light when struck sharply. Like many desirable minerals lurking in prospecting country, unfortunately sphalerite doesn’t react to metal detectors.?

    A Final Word
    The foregoing is intended to illustrate that sensitive metal detectors can be utilized as a supplementary tool to assist with evaluating rocks and minerals. There is no question that the benchtest has serious limitations, particularly if trying to distinguish positive signals produced by some types of iron mineral inclusions from weak conductive signals.?
    That notwithstanding, a positive signal that persists below the F75 / GB45 compensation point cannot be confused with iron mineral negative threshold signals produced at that same compensation point. Therefore a positive signal merits further investigation. Such signals are almost certain to be generated by a marginally conductive mineral or a metalliferous substance.?
    On the more interpretive side of a benchtest, we need to point out that weak positive signals from lower-grade samples of minerals such as arsenopyrite, galena, pyrrhotite, chalcopyrite, and doubtless a few others, may disappear well before the GB control is reduced to the F75 / GB45 compensation point. We learn early that benchtests are frequently equivocal and require interpretation based on any further evidence that might support the benchtest result. Look for iron oxidation in addition to structural or other physical evidence as described above that could explain why a sample reacts as it does to a metal detector.
    Jim.
    This article was?promoted to an article from a forum thread. Additional information may be found there in follow up posts.
    ?

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