GB_Amateur

12 hours ago, Tortuga said:

Like Steve said Fistfuls of Gold is a great read. It took me a while to finish it, was slow getting through some of the hardrock chapters etc. but I wanted to read the whole thing.

Most other books out there just have brief chapters on nuggetshooting (look for bedrock) or aren't really up to date on some of the newer metal detecting technologies. 'Fistfuls' pretty much sets the bar covering all aspects of gold prospecting that you'd need to know about.

I like to read a lot on the metal detecting subject: internet, magazines, and books of which I have a decent collection.  As you say, Tortuga, many books are pretty basic and say the same things.  They are for beginners (even some with, IMO, misleading titles that imply they aren't).  However, Chris's book is clearly not (just) for beginners.  It is the textbook for the geology of gold.  For someone who does not have an education in geology it is a deep read.  In fact, make that plural because this is one of those manuals that can't be absorbed in one reading -- some sections (for me, anyway) require more like 3 or 4 coverings to really get full value.  I'm in my 2nd (and some cases 3rd) time through the book right now.  Chris does the same detailed writing in the ICMJ where he is (at least in the issues I've read) the #1 contributor.  BTW, anyone who wants good reading material on metals geology, prospecting, and mining with emphasis on gold should definitely subscribe to this journal.

I get mildly annoyed when titles of books use words like 'bible', 'encyclopedia', 'manual of', when they really should state 'introduction to...' or 'elementary basics of...' or 'beginner's guide to...'.  IMO, Chris's book (whose title uses none of the above words) is certainly qualified to wear one of the stronger words/phrases.  It's far more than an introduction, at least from what I've seen of its competition.

23 hours ago, Cabin Fever said:

Last week I dug a 1921 D Mercury dime and a 1931 S penny on the same day.

Could you give an estimate of how many hours you spent digging last week, and how many total coins you dug?  I'd like to be able to estimate how rare such an occurrence is.  The number of coins dug is the more important one.

The word 'impressive' doesn't begin to do this justice.  If those are nearly independent events (that is, we're not talking about someone stealing a coin collection and then dumping it in the local park) this is approaching astronomical.  I recall an article in Coin World newspaper back in the the 60's where an estimate was given of the number of hours searching through bank rolls it would take to find various scarce and rare Lincoln Cents.  Wish I could find that article.

On 4/24/2016 at 3:06 PM, auminesweeper said:

It takes a while on this site to figure out who is who and where each resides.  With that moniker and kangaroo image, for the longest time I figured you were from Australia and from your posts I surmised possibly California.  Is it really United Kingdom?

Finding a US Silver dollar in the home county is a lifetime achievement even for a very accomplished coin hunter.  Obviously the reason isn't the signal it gives, and it isn't so much the age (although, except for some special collector non-circulating editions, the last business strike occurred in 1935).  The biggest reason is that they didn't circulate.  I know there are quite a few Nevadans who read and post on this site.  The history of the US silver dollar is intimately tied to Nevada.  If you ever get bored at bedtime, get one of Q. David Bowers's books that cover the U.S. silver dollar.  Basically the vast majority of U.S. silver dollar minting was driven by the Comstock Lode discovery and silver recovery thanks to their aggressive U.S. Senator.  The problem was that the impetus was supply-side driven.  That is, the laws passed to mint a large number of these (supply) wasn't met by an equivalent desire (demand) for them to be minted.  They were physically heavy, they represented quite a significant investment (a dollar was a lot of money in the late 1800's and early 1900's), and they had some competition from paper money.  As a result most went into bank vaults, especially U.S. Treasury and U.S. Federal Reserve vaults, unlikely to ever see the light of day.  Not surprisingly (and likely known to many of you Westerners) the primary geographical area of circulation for U.S. Silver Dollars was the U.S. West.  Even then they didn't trust banks (to keep their valuables) nor the government (i.e. those worthless paper promissory notes)!

There were significant meltings of these coins in the early 20th Century.  But many survived in mint condition in these underground storage havens.  One of the great coin collecting coups of all time occurred in the 1960's and 1970's when the mint released a lot of these hidden treasures (for, at the time, premium prices).  That was both a boon (to the wanting collectors) and bust (to those who held rare editions, only rare because of the few that were ever circulated).

But as far as silver dollars in the ground?  Yes, there are some cache/hoards still out there.  But just think about it -- if you dropped a silver dollar, how likely were you to notice when it happened?  Given its size, how likely that someone else didn't find it sitting on top of the ground?  And when you realized you just lost something on the order of or greater than a day's wage, wouldn't you retrace your steps multiple times to try and recover it?  None if this could occur if you didn't have the means to possess one of these beauties in the first place.

No, U.S. silver dollars aren't nearly as rare as U.S. gold coins.  Find one of those and you should be nominated for the metal detecting Hall of Fame.  But silver dollars are very rare finds and if you didn't celebrate when you found that one, please invite me to the party when you do.

Nice review -- very professionally done.

I will point out a couple minor inaccuracies.  Garrett pans have had mounting holes in the edges for nearly 40 years.  I still have one of their original "Gravity Trap" versions.  I can't say that every pan they've ever produced has a hole but recently I bought their Super Sluice and it has one.  Also the Super Sluice has the angular transition from flat bottom to conical side that you compliment the new Minelab for having.

I didn't catch you mentioning the cost but I recall from an earlier thread it was supposed to be competitively priced.

18 hours ago, argyle said:

Being a depth of sliver thread that Eklawok started, and seeing already a couple of coins that have been found by detecting have been posted up, (geez they didn't leave much room on the Liberty Dime for the full date) it would be nice to see a few more pics and explanation of type of coin, depth found and with what type of signal initially made you dig, the rarity of it ect.

I appreciate people posting still pics and videos, as on YouTube, of detecting.  The videos there I like are the ones that show the actual detecting.  Then the viewers can experience important things such as the sound, the ID on the meter, and not least I'd like to know "what were the settings on the detector?"  How deep did the object turn out to be?  Was its orientation such that it gave an unexpected signal for the type object it was?

The videos that skip all the detecting (and digging) and simply show the find might as well just be photo albums of still pics.

19 hours ago, 1515Art said:

Hi GB_Amateur, I'd never try and judge a swamp person by his cover, I bet most of them could McGiver us out of a tough spot with some shoe strings and tin cans if we were in a jam, but they do put on quite a show...

 

Yeh, I probably overstepped my bounds.  Thanks for keeping me honest.  I really wanted to refer to Porter Ridge which is a cable TV show that was taped just about 20 miles from where I live but didn't make it past the first mini-season so I figured no one would know what I was talking about.  At least there I would be deriding my own people, which isn't as bad as picking on someone who isn't next of kin.  I was also likely harsh criticizing the local gold prospecting club.  They mean well.  But it just amazes me how ignorant (too strong?) they are about the rest of the prospecting world.  E.g. my sister belongs to a metal detecting club in Denver and they have a 20+ page, well laid out monthly newsletter with finds, etc., monthly group hunts, and many monthly meetings they have interesting speakers (e.g. one of the 'stars' of the TV show Gold Rush).  I asked our club president if they ever have speakers here.  His response:  "Why would we do that?"  I pressed further:  "Well, for example, we could get a geologist to give us advice/hints/etc. on where the best places to find gold are around here."  He retorted: "Oh, we already know that!"  Now I hope you are starting to understand my frustration.

I emphasized out west, but most of you know there is gold in the southern Appalachians.  Still, we don't have BLM or National Forest land where you can just drive+walk on and (after making sure you aren't claim jumping plus doing other research) start swinging a detector.  Prospecting & searching for gold is illegal in our Indiana state forests with one exception, and there (I'm told) all you are allowed to use is a pan and small scoop.  I'm definitely going to ask if using a metal detector is OK there (that state forest also is within 30 minutes of my home) but I'm not optimistic they'll say 'yes'.  Again, I asked the local club members if they thought it was OK and they said "why would you want to do that?" 

7 hours ago, Eklawok said:

Wow....so much good information here. When I posted this thread I didn't realized how much good "searching" information that I would receive. It really is inspiring to me to go and really look in the older areas where I live. I just pawned my kiddo off on the grandparents tonight for the weekend and may have to do as such tomorrow. In the spirit of this thread,  I have snapped a few pictures of a dime that I had found a few years ago in some pocket change. It is a 1940 something. The last number of the year has rubbed off. It appears to be a 1946. I have actually kept it separated in one of my gold pans. I think that it would be cool to find a buffalo nickel or another older coin just because it would be older than what I am (being born in 77). Kinda funny too now that I think of it, I haven't seen a bicentennial 1976 quarter in a while either. I m8gbt have to check my change jar for one. I remember them as being quite common at one point when I was a kid.

 

Nice.  Note the mintmark (looks like an 'S' for San Francisco) on the reverse down by the base of the torch.  Very likely a '46 since that was the first year and that last digit doesn't look much like a 7, 8, or 9.  Yep, finding one like this would make my day.

If I haven't bored everyone (and of course you can just quit reading), I think I shortchanged the Lincoln Cent a bit.  For starters the Wheat reverse ran from 1909-58, not 57 as I stated erroneously.  This should be easy to remember if you realize that 1809 was the year of Lincoln's birth and/or 1909 was the first Lincoln Cent (commemorating the centennial of his birth) and they changed the reverse exactly 50 years later, adding Washington DC's Lincoln Memorial to replace the wheat.  (I haven't kept up but I'm guessing 2009 is when they replaced the Memorial.)

I never minded the Memorial -- kind of attractive, IMO -- but what happened in 1982 burned me.  Prior to that year all Lincoln Cents (with the exception of the 1943 Steel issues) were 3.11 grams total weight of which 95% was copper.  The other 5% apparently varied over the years as some combination of tin and zinc (but not necessarily both).  So 146 pennies weigh a pound and ~153 pennies contain a pound of copper.  The high price of copper in 1982 (many of you recall the high price of precious metals at that time) was such that the penny cost way more to make than its face value.  So they switched to a core of zinc (mostly) alloyed with a smidge of copper and then plated that with pure copper.  Both compositions (old and new) were used in 1982.  The new penny was lighter (2.5 grams).  Worst was what all detectorists in this country know -- if one came in contact with damp soil it started to deteriorate due to galvanic action.  In other words the mint was making batteries!

Ironically the price of zinc went up to where the new pennies weren't cost effective to make either, but they kept doing it anyway.  Now zinc is down to $0.86/lb but copper (much lower than its of $4.62/lb on Valentine's Day 2011) is still at a reasonable(?) $2.28/lb.  I once asked a metals salvage dealer if he was bothered by the fact that it is illegal in the US to melt circulation coinage.  "Only if I get caught." 

11 hours ago, 1515Art said:

i was 8 years old in school lunch line one day and we had been collecting for a couple of years now so I knew even then the key dates I had asked the lunch lady if I could check the dates of the coins in the till box and spotted an 1893s Morgan in the till. With the innocence of an 8 year old I explained this was a key coin we were missing and asked if I could use my lunch money for the coin instead of lunch that day, she declined my request.

Oh, 1515Art, I feel your pain!  Your knowledge/skill made her a whole bunch of money, if she believed you.  And all you got was this lousy story.  An 1893-S Morgan I could only dream about and you almost had one in your collection, at the age of 8.  Sometimes the stories are worth more than object, but I don't see that being the case here.

Having been alive and coin collecting in the magic year of 1964, I think I can add a bit of perspective here.  As most of you US residents (should) know, all dimes, quarters, and halves were 90% silver in 1964 and prior.  What you might not know is that in 1965 there was an attack in the US Congress against coin collecting.  In their infinite wisdom the Congress decided that coin collectors were a menace to the US economy.  In 1965 (and for the following few years) they did everything they could (which was a lot) to hinder coin collecting.  Prior to 1965, coins carried mint marks indicating at which location they were minted.  That was stopped in 1965 (but soon later restored in 1968).  Related, but likely driven by other concerns such as the cost of the base metal required to make coins, silver was rejected and a copper core plus copper-nickel faces ("clad") replaced the makeup of dimes, quarters, and halves in 1965.

Ironically, in the late 90's and following, Congress decided that coin collectors (and hoarders) actually added to the value of the national treasury and minted collector coins, such as the popular state quarters!  But that is a sidelight which is of minor or no relevance to coin hunting detectorists.

Let's step back a bit.  Coin collectors in the purest sense know which dates and mintmarks are scarce/rare/valuable.  The charlatans of the hobby only recognize gross features.  "Wheat cents" (1909-1957) were easily recognized because of their reverse design.  Buffalo/Indian nickels, and their predecessors (Liberty or 'V' nickels) even more obvious, as were other mintages of Indian Head pennies, Mercury dimes, Standing Liberty Quarters, and Walking Liberty halves (throw in the Barber designs pre-1917).  So whenever the public heard that a particular design might be valuable they vacuumed them up in short order (being a few years, typically).

The 1964/65 transition from 90% silver to clad wasn't quite as easy for the numbskulls to figure out, but both the edge (copper center of the clad coins) and overall color of the faces (white silver vs. dull off-white cupro-nickel) made the 1964 and earlier coinage fairly easy marks.  In my observation the clads replaced the silvers in about (or less than) five years.  The Wheaties hung on longer, and the Jeffersons, with no clearly defined marker, were the last holdout for true coin collectors desperately grasping the previous simple practice of searching pocket change and bank rolls for keepers.

Putting it all together, 1970 was pretty much the death knell for silver coins in US circulation.  (On a side note, Canadian coins had a similar timeline.)  That's 46 years ago.  If you find a silver coin in the ground in the US you can be 99% confident it was deposited at least 45 years ago.  If you're hunting a park, schoolyard, churchyard, ballfield, etc. which was at best a farm field 45 years ago you are very unlikely to find silver, no matter how deep your detector can see.  (Obviously the exceptions occur when prior to being public places those locations were frequented by humans dropping pocket change.)

Give credit to those who have noted here that there are many variables that lead to the depth of silver coins.  Not the least of these are seasonal freeze/thaw heaving which can push coins deeper but also pull them closer to the surface.  On an opposite point, the idea that "all of the good coins have already been found" implies giving previous searchers credit for careful, systematic, thorough ground coverage and digging.  That simplistic view ignores the sloppiness/laziness of human nature.  Throw in the fact that as detectors get better they find things even the best of previous generations were unable to find due to the technological limits of their equipment and the improvements today.

Personally I'd rather spend all day resulting in finding a single common date silver Roosevelt dime than one resulting in a bagful of clad quarters.  For me it's not the total value at the end of the day but the thrill of the specie.  Silver, you may be only a prince compared to King gold, but you are still royalty.

You guys out west (especially in the Sierras) don't know how good you have it.  Look at all the GPAA shows in the Rockies and west.  And the ground you have to search dwarfs all of that.  I subscribe to the ICMJ and read it voraciously each month, but it's not the same being an armchair prospector.

Here in the US Midwest we're lucky to have a metal detecting club within 4 hours drive and what passes for a prospecting club looks like the lower half of the IQ scale from the TV show "Swamp People".  Most of the nearby club members don't even know what a metal detector is and the ones who do tell you "it won't work around here".  One 'expert' told me there were no nuggets around that a metal detector could possibly pick up and then in the next sentence told me he found the largest nugget (with his dredge) anyone had ever found in the area.  Yeh, figure that contradiction out!

I'm going to try and plan a vacation around an ICMJ conference in the next couple of years.  That's a lot of travel expense and nights in hotels, but you'll make it worth it.

Plan B (maybe I'm supposed to start a new thread...)

Thanks to the responses, particularly Geotech's, I'm abandoning the plan to modify the Garrett BFO coil for use on the TDI/SPP.  There are just too many required tweaks and, worst, when it works it doesn't work very well.

I have four coils as of now, maybe more soon .  12 inch White's stock (open structure, circular) "Aussie Mono", 6 inch (closed, circular) Super Pulse 150 (mono), 5in X 9in (closed, elliptical) Miner John folded mono, and 3.5 in X 6.5 in (closed elliptical) White's(?) mono.  The 12 in and 6 in rounds were sold by Jimmy Sierra with the original package.  As of now the latter two small coils are going to be my go-to dry land coils with the 12 in for quiet, flat ground.  That leaves the SP-150 as the weak sister, so....

I started this thread wanting a neutral (or even negative) buoyancy coil.  My current plan is to modify the SP-150 to become just that.  I started out by cutting it open -- actually easy since it is a two piece case, sealed around the belly with silicone -- so I just cut the silicone with an Exacto knife.  I did have to disconnect a ground wire soldered and taped to the bottom piece.  Pretty simple inside and lots of strong, tough epoxy holding most everything in place.

I don't really want to turn this into a bitch-fest, but I've got to wonder why this enclosure was used.  The lower piece is way too deep -- by 1/2 inch -- than it needs to be.  The first issue here is that it results in dead volume (leading to extra buoyancy).  But worse, it keeps the coil -- specifically the windings which are the real coil -- an extra 1/2 inch off the ground.  I can't count the number of pieces of advice I've read that say "make sure to keep the coil as close to the ground as possible.  Scrape the bottom across the ground for best signal penetration."  So they build a coil housing that wastes 1/2 inch of useful depth.  (scratching head...)

First goal is to find a replacement lower section -- effectively a 6.5 inch diameter low profile(!) coil scuff cover.  Then I need to find some small, non-conductive weights to put inside before sealing it up.  My measurements + calculation say I need about 240 g of mass (so about 1/2 lb weight).  Note that placing it inside the enclosure is the most efficient (least amt of weight) way to do this.  Putting anything on the outside of the coil (e.g. sandbag) adds to the overall volume and thus the buoyant force.

Now here's where the geologist's advice is requested.  Most dense materials are conductive.  Non-conductors tend to be low density.  Most rock has specific gravity in the ballpark of 2.7.  I have some marble (metamorphosed limestone?) right at 2.7 which I can probably break/cut and epoxy inside.  But is there something better, because the volume of marble required is going to make this a tight fit.  Any non-conductive, non-magnetic (oh, and affordable) materials out there that anyone here knows about with higher densities than typical rock?

George, that's some serious info I would have struggled mightily to figure out (best case).  It's sounding like the Garrett BFO coils just aren't going to make the grade.  What do you think about the Garrett Sea Hunter 8 inch mono that Rick mentioned worked on your Crossbow?  Does that have a shot on my TDI/SPP?  Just to be clear, I'm not really doing a science fair project as an existence proof but rather trying to get a cost effective solution that works about as well as could be expected from a factory coil.  Right now (AFAIK) the White's coils and the Razorbacks float, and I don't consider that satisfactory.  The Coilteks, even if they are neutral or negative buoyant, carry a heavy price tag.

Thanks again.

3 hours ago, SLGuin said:

It occurs to me that with the advent of the Makro Gold Racer and others that there might be some real bargains in used gold detectors where people are upgrading to the newer top of the line models. Your thoughts?

SLG

 I'm pretty new to this but I've noticed some great bargains on Ebay lately (like a Fisher f70 going for $300 within the past week).  It's hard to say from one or a few datapoints and maybe last year at this time there were equally as many bargains.  However on your first point, in the first 3 1/2 months of 2016 we've already seen the release of four new models (Makro Racer 2, Nokta Relic, Garrett Ace 400, and White's MXSport).  I may have missed some, and there could be more soon.

Everyone knows his/her budget constraints and comfort levels.  IMO, and this is purely hypothetical, if someone has $400 available and will have to wait 4-6 months to save another $400, then it's not worth the wait.  The time spent hunting with a very good used detector is better than the best new $800 detector futures.

Thanks, George and John.  Thought of another question for you guys since you've been so generous with your knowledge:  I seem to recall reading that putting a non-TDI coil onto the TDI requires that (or at least works better if) the pulse delay is adjusted.  My TDI is the Sierra Super Pulse (SPP) which has the delay locked at 10 microseconds.  When you run your TDI with the non-Whites coils do you adjust the delay away from the minimum (10 us) setting?

Thanks, Rick!  Sounds like there are more coils out there that potentially fit my need.  I wonder if the Garrett Sea Hunter coils can be modified to work on the TDI.  The 8-inch (open) looks promising for what I'd like to have.

Regarding Coiltek coils, they appear to be mostly built for Minelabs but I do see the TDI occasionally mentioned on their Ebay descriptions.  Did you have to get the 14x9 modified (e.g. change the connector) or is that a standard issue?

UPDATE.  I finally got an inductance meter (my electronics tech expert has responded but as yet has had no time to drop by) and I measured the inductance of three of my TDI coils, all around 300 microHenries -- calling that uH from now on -- as Roughwater said they should be.  I actually measured closer to 350 uH, but as always this could be a calibration issue of the meter.  I then measured the Garrett BFO coils and they came in around 180 uH, about 50% higher than Geotech said he had measured.  This also could be calibration or just variance between actual coils.  And he did say maybe he measured a very large (24 inch) coil, but I wouldn't think that should matter.  If the detector wants a certain inductance then shouldn't all stock coils be built with that inductance, or something close?

It's interesting to note that the Garrett coils actually have two windings, in some ways similar to White's "dual field" coils, except that only one is used at at time on the Garrett.  There is a switch on the detector unit that allows you to select between the small and large coils.  I was hoping that if I put the two coils in series and then measured their combined inductance that it would simply add the two and I would get close to the desired 300-350 uH.  That didn't happen.  I got around 200-210 uH when the coils were in series.  This may just be due to the orientation/geometry of the coils.  (I need to review my physics texts.)  Note the Garrett BFO coils are not concentric but rather co-planar, non-concentric.

So where do I go from here?  I'm still counting on my friend to provide more insight.  I'm wondering if adding an external choke (coil) in series, well away from the searchcoil, would work.  Of course it would have to be well shielded, otherwise it would respond to varying background metal just like a standard searchcoil does.  And even if kept quiet it might rob the intended coil of its sensitivity.  I started out thinking this project was a longshot and the odds are getting even longer.  But, you know the old saying, "the next best thing to a positive result is a negative one."    Stay tuned.

Welcome, dustman27.  To my knowledge, the Teknetics G2+ is the same as Fisher F19, and both are close relatives to the (newer) Fisher Gold Bug series.  I have the Gold Bug Pro with all three stock coils.  Regarding ease of use, I don't think it gets much easier for a detector that has this much firepower, but I'm not experienced with other detectors so take that opinion with a grain of salt.

$400 is a very good price for a G2+ with the 11 inch open DD, assuming it is in top condition.  Best price for a new one on Ebay (that I could find) is $750, including shipping.

11 hours ago, Roughwater said:

I hear ya Ridge Runner.  A few years back I broke down and bought a newer used 4x4 Toyota FJ Cruiser.  Price was a good bit more than I'm used to paying but wanted a good off road capable vehicle for hunting and when the roads get icy.  I liked it but the wife hated it, hard to see behind, back seat not real comfortable and can't roll back widows down but what I didn't like most was we took a trip to Ohio and back and couldn't even get 20 mpg highway.  I think more like 18.  I felt like for the money I should be able to get at least 20 Mpg.  So to please me and my wife I traded the FJ for a 2014 Subaru Forester.  My wife loves it, it's all wheel drive all the time and on my latest 40 mile trip I got 35 MPG.  The 4 Cylinder in it feels like a strong 6.  The 4 WD is excellent. We have 30K on it and it's never been to a shop or dealer.

I've been researching online to try and find the right off-road vehicle for when I retire in a couple years and have time to prospect out west (CO, AZ, NV, CA, OR).  I want something that is reasonably fuel efficient and comfortable for the highway driving but also can handle rough dirt roads (including washouts).  The Forester sounds great for the former requirements but how does it do in the back country?  I'm not trying to blaze my own trail but in my limited experience out west you sometimes need decent ground clearance and good traction, especially when you want to get close to where the gold can still be found.  I don't mind parking and hiking a couple miles but the more time spent hiking the less time swinging the detector....

9 hours ago, Cabin Fever said:

I would say the 1912 s has at least F-12 details but does have some enviromental damage as you can see from my close ups here.

Not sure what you mean by 'environmental damage' unless it is the green(?) discoloration, which doesn't look bad in the photo.  Nice to see that you've graded this conservatively -- rare amongst most coin collectors.  This is an excellent case for why hunters shouldn't be rubbing coins when they pull them out of the ground.  Sure, if it's a common date and just valuable for the metal content (i.e. silver) or as a 'trophy' piece then it doesn't matter.  But occasionally (as you prove here) you get a scarce date with numismatic value.  A little patience taking the coin back home and soaking, etc. will maximize the equity.  I'm just flabbergasted watching YouTube videos where the searcher finds a coin and then just has to rub the heck out of it until he sees the date.

That 1912-S Lincoln looks to be in nice shape.  Did you grade it?  I'm impressed at how good your coppers look after being in the ground for approaching a century.  My limited experience coin hunting around here got me thinking something in the soil eats away at the old Lincolns, taking away detail (more so than just the typical pocket wear they suffered before being lost).

Thanks to all for the responses.  I have a friend who is a top notch electronics tech and he'll have an inductance meter so I can do a check of both coils before trying to hook anything up.  I figured there was some kind of dead weight solution (e.g. sand bag or the Anderson disk) but the latter apparently only fits the large coil and the former just seems so inelegant!  (I really prefer small coils around here since we have, oh, 200 years of trash spread everywhere, including the waterways.) 

And regarding the warranty, I likely already voided that when I changed out the (faulty) 5-pin male panel mount on the front of the control box -- the coil's cable attach point.  Further, I've been strongly considering adding the conductivity switch (covered on this forum in another thread) which for sure would void the warranty.  Lastly the S-rod is too long to fit into my Pelican hard shell (airline proof) travel case so I need to shorten it before traveling to the Colorado Rockies in June.  Some people just can't keep their clumsy mits and dull tools off a pretty device.    If the inductances match (or are close) I'll probably try the retrofit.  I didn't mention that the lower rod of the Garrett mates perfectly with the upper rod of the White's -- as if they were designed to be compatible (very unlikely, but maybe both companies use the same source for their components??).  If I do that I'll post here the outcome, assuming the resulting fire doesn't also burn up my computer.

(sorry, hit the wrong key)  ... that the PI and BFO share the property that they both have a searchcoil that shares one loop for both sending and receiving.

So, you might now guess what I'm thinking.  Could I mate the Garrett BFO coil (which is neutral buoyant) to my White's SPP/TDI?  Yeh, I know, "you'll shoot your eye out, kid!".

I recently bought (from Steve) a White's Sierra Pulse Pro (SPP) PI detector which is effectively a TDI/SL without a delay adjust (locked at 10 microseconds) and without a conductivity switch (locked in the 'All' position).  When I took it down to the creek with the Minor John 5in X 9 in folded mono coil I was disappointed when it floated.  Apparently most coils are either for dry land use (thus lightweight) or for underwater use (heavy).  I've been spoiled by my Fisher Gold Bug Pro 5 inch round DD which exhibits (by design, I'm confident) neutral buoyancy, meaning it neither sinks nor floats when placed under water.

Besides the three coils that Steve included in the sale I now have a fourth -- a 3.5 in X 7 in White's coil, which I understand was an early (prototype?) version no longer available.  Unfortunately it joins the 5x9 Miner John, the White's 12 inch "Mono Aussie", and White's Super Pulse 150 (mm diameter mono) as floating searchcoils.  Of these four only the 12 inch Mono has an open structure.  There are other coils available from White's and from Razorback (Miner John) but they don't seem to advertise whether or not they float, sink, or are neutral buoyant.   Furthermore, as those of you who own PI detectors know, they aren't cheap, so buying with the hope that they will work well in water seems like a costly hypothesis.

I had an idea, which seems crazy, but then occasionally crazy ideas work out.  I have a Garrett BFO Master Hunter detector I bought as a backup (for a Garrett's Groundhog 15 kHz VLF/TR) back in 1979.  BTW, it still works.  I also read in Charles Garrett's 1985 "The Advanced Handbook on MODERN METAL DETECTORS"

While you're at it, Elkawok, check how well the two connectors are mating.  On my White's SPP/TDI I had a problem just this week when the male connector (mounted to the control box) failed.  The inner part (plastic that holds the pins) pushed completely into the detector.  The female connector (cable end for the coil side) screwed onto the male connector just fine but the pins weren't in contact.  Initially they did contact slightly and the detector worked, but then lost contact and even though it sounded like it was working -- had a normal threshold tone -- it wouldn't respond to the barbecue grill.  That was my first clue.

New to this forum and I did some searching, but sorry if this has been covered before.  I'm going to buy some rare earth (neodymium) magnets to take prospecting, but want to make sure I don't do something stupid in the process.  I already have one (N52 cylinder, 1in X 1in) and know how powerful these can be.  They come in many sizes, shapes, and strengths (see CMS Magnetics website at www.magnet4sale.com for a huge selection).  My first concern:  is it possible to damage the electronics of a metal detector by getting too strong of a field closeby?

Second concern:  would getting too powerful of a magnet be a detriment in either cleaning up black sand or clearing a trashy areas of bits of iron?  I have one of those plastic encased plunger magnets that come with panning kits but it seems really wimpy.  But maybe wimpy is good for the purpose of cleaning out black sand at the end of panning and too strong of a magnet would be a problem?