Question on Iron Reject Using GPX4000

[1Boeing737]

Has anyone ever had good success at all when using your Iron reject funtion on your GPX detectors? If so, what did you notice to be more helpful when using this function. What about the performance tradeoff as far as depth, signal, and other important variables to watch out for? I have really never made use of this function because of missing the gold rumors you normally here. I know it works, but to what extent can you expect some loss, or gain when using this function? Any field testors?

Thx

Mark

[Tony Teixeira]

Good question Mark,

When I was driving home the other day I was thinking somewhat along the same lines, since I was using a mono coil the iron reject function is not available, I am going to play with both a DD coil and mono coil this weekend just to get the feel for them and how they react. Sorry I can't answer your question but am looking forward to the answers you recieve.

Tony Teixeira

[1Boeing737]

Good question Mark,

When I was driving home the other day I was thinking somewhat along the same lines, since I was using a mono coil the iron reject function is not available, I am going to play with both a DD coil and mono coil this weekend just to get the feel for them and how they react. Sorry I can't answer your question but am looking forward to the answers you recieve.

Tony Teixeira

Hi Tony,

Its funny, I've been using this detector and its predecessors like it for years and never used that part of it. The only Iron descrimination demonstration I have ever seen, was at a gold show in Mesa AZ. It was with a lobo S.T.

It descriminated a pair of pliers, and then sounded off on the nugget next to it. I thought that was pretty impressive, even for a bench test. Hopefully we will have some sound off here from a few experienced folks on that part of the field.

[nuggethunting]

Hello Mark,

There has always been debate with discrimination on Pulse Induction metal detectors, at least for gold nugget hunting. I have used them on the Minelab PI's with some success, but I would never put 100% faith in them. Several years ago we were up in Alaska and we thought we had the disc. figured out on the GP3500 and GPX-4000. Several days later one of the guys found a nice 3+ ounce specimen laying right on top of someone's dig hole. We think someone dug the target up and it "blanked out/disc." and the person just walked away. After the 3+ ouncer was found by another person, we all started to question the disc. and done some testing that evening back in camp. Low and behold, just about all the big specimens were "blanking out!"

Keep in mind, most of the gold in this location was specimen gold, so that does make a difference. I think when you dealing with solid chunks of gold, you have a much less chance of disc. out a piece of gold. I would be careful using the disc. in places where the gold is in quartz, ironstone or other type of country rock. Some places you might not know the origin of the gold, so to be careful at first you might want to use a lower disc.

Hope this helps a bit,

Rob Allison

[Hawkeye]

Mark

I had a similar experience as Rob. I had a good signal from a target, a good strong signal right from the start. When I took off about ten inches of material the signal blanked. I almost walked away but I thought If that was iron it would of discriminated from the first response being such a strong signal so I dug it up to find a 17 dwt specimen of wire gold in quartz that had a lot iron staining to it. The best rule of thumb is to dig everything but in some cases thats just not possible with so much surface trash in a lot of areas. I have found that the discrimination is useful for surface trash but is very unreliable on targets of any depth. When I am using a DD coil with my 4000 and in the discrimination mode I usually set the discrimation at about 20 on the adjustment. But one thing to remember is the biggest discriminator that determines wheather to dig a target or not is sitting on your shoulders.

Wes

[1Boeing737]

Mark

I had a similar experience as Rob. I had a good signal from a target, a good strong signal right from the start. When I took off about ten inches of material the signal blanked. I almost walked away but I thought If that was iron it would of discriminated from the first response being such a strong signal so I dug it up to find a 17 dwt specimen of wire gold in quartz that had a lot iron staining to it. The best rule of thumb is to dig everything but in some cases thats just not possible with so much surface trash in a lot of areas. I have found that the discrimination is useful for surface trash but is very unreliable on targets of any depth. When I am using a DD coil with my 4000 and in the discrimination mode I usually set the discrimation at about 20 on the adjustment. But one thing to remember is the biggest discriminator that determines wheather to dig a target or not is sitting on your shoulders.

Wes

Thx Hawkeye,

I was re-reading the manual on the Iron D. section again, and it makes since what you and Rob are saying now. I do appreciate your imput. I guess that part of the detectors function as far as improvements go, will be a very useful tool one day if mastered. It should be one of the most sought after improvements for most prospectors here in the states who are accustomed to digging in the trash like myself. I remember hearing from an old friend (Montana) who got me hooked on this hobby, and who said the Iron D. would be a high priority on a wish list of improvements if he could improve anything. Of course back then, we were using the SD-2100.