question about deep iron

[JohnnyI]

After reading Andy's book several times I am still a little confused about the best settings for very deep coin signals where there are a lot of deep iron square nails. It suggests that you can lose deep coin signals because ferrous readings can go as high as 27 on these deep targets......so I'm going to switch from 22 to 27. But it also mentions that hunting in ferrous audio can be helpful when there is a lot of iron. It also mentions however, that with the less discrimination, it can be more likely to latch onto a ferrous target and not hear the conductive one. I guess my question is, which is right for deep iron with deep coins?, If you are going to reduce discrimination in an iron infested location, what is the best audio to use, conductive or ferrous?

 

[3RINGER]

PM sent

 

[Nick A]

My take on it is that the E-Trac does a great job of discriminating iron. Depends on the type of hunting and site. I have found that running high sens helps make the conductive stuff "pop" a little better. With coins near iron, they still sound high tone, but read lower. For the type of site I imagine you have, I might try reducing the ferrous to 27 and try it and see what you're digging. If you are getting square nails, bump it up slowly back up towards 22 until you stop getting nails, or only get a few. This way you have the perfect setting for your site.

All depends on the site for me. An iron infested house site or barn, I'm not gonna worry about the few coins that I might miss. Just not worth it. Now if you tell me it was a barn where they held barn dances every Saturday through the early 1900's totally different story... I'll probably be digging most every signal there.

That said, I think the E-Trac really does a good job sniffing out coins next to trash, and the Pro coil is killer at separation. The key thing to keep in mind with separation is to go slow. I have confidence in my machine that if it's there, I'll find it.

As far as audio, you're gonna do best with what you are used to using all the time. Tones are so important, I wouldn't mess with what you know. If you switch, you have to relearn, unless you're way better at learning tones than me.

 

[JohnnyI]

"All depends on the site for me. An iron infested house site or barn, I'm not gonna worry about the few coins that I might miss. Just not worth it."

Ha, yes, I guess "worth it" is in the eye of the beholder sometimes. This site (my home) was originally built in the 1680's. burned sometime before 1732, and was then rebuilt, with additional fill covering the lawn from a 1780's addition and cellar. What is in that bottom strata is what I want to find, as it will be the most historically interesting. (a number of test pits I've dug have already turned up a 1655 liard, and a number of contemprary buttons, so I know there is more to be found. Trouble is, that bottom strata is covered with a layer of the remains of the burn. I've already spent ten years on the upper strata, which has produced numerous large cents, half-cents, dimes, half dimes, reales, etc. , all common to the later colonial and federal period. All that occasionally turns up now with the new machine are small brass tack heads, small shot, boot eyelets, tiny lead sprew, etc. which I'd missed before. Anyway, It's the story the deep strata will tell that I am after now, and there will be a consitent layer of it (if I can only get to it.)

Again, the problem is the depth, and the fact that the fire has strewn square nails at a very deep level directly over the original 1680's surface. In addition, centuries of coal fires have produced many hot rocks which may blanket other small signals, as well as years of normal nails in all layers. The depth itself is a challenge, as in some areas the original surface goes down well over a foot to a foot and a half, and it's compromised by all the nails. Digging every nail is not an option (ha! yet!) as they are virtually everywhere, with little to distinguish them due to the amount of rust and halo effect. In the end this may be an impossible task without backdragging, but if a detector can manage it, I think this one will to a degree, and why strain the marriage by bringing out the kubota. too soon! The small 6 inch coil is a help and has very good depth also.

Anyway, thanks for the advice on sensitivity which I'll try again. It's the ferrous mode question which I'm still curious about though, as there seems to be some contradiction about it in the book.

 

[3RINGER]

Did'nt know about the depth problem to hit the targets under the fill. Try the same info I sent ya with a WOT or SEF coil. The 12x15 SEF I use on the farm fields here has great depth and from what I hear the WOT does as well. When you find yourself in the nail/iron areas really slow down and pick it apart.

good luck and HH

 

[Nick A]

Well that's quite a site you have there, and you own it, so I'd be all for digging and sifting. You have nothing but time on your side. Sifting will get you all the fascinating non-metal stuff that's there too. I think you have a real challenge between the possible depth (real deep!) and the amount of trash on top of a potential good target..

 

[JohnnyI]

"so I'd be all for digging and sifting"

Yeah, but then I'd never know if it would be possible to someday tweak the machine enough to hit some of this low stuff without digging and sifting.

 

[1goldsniper]

Next time you come across one of the nail infested areas where you can swing the coil 2-3 times with out the threshold breaking thru the nulling try throwing down a quarter and see how well your machine see's thru the trash!