E-Trac Fe-Co numbers

[Jason in Enid]

OK, we all know that the E-Trac is a killer on the silver coins, so I have a question in regards to something from Andy's book.

Andy says that while the Co number will stay basically solid, the Fe numbers can raise as the depth of the coin increases. All the way up to an Fe of 27. This is the reason for the pattern he uses. I don't think I have seen numbers change very much at all, but I know that each site can be different.

What has been your experience on deep silver? Do the Fe numbers raise that much?

[OkieDigger]

They can get high (20's), but it's a jumpy high.

However, I dug a wheat that was only 4 down today. It was reading FE 18 and 20 pretty solid. CO was 44 solid I believe. The tone was good in every direction so I dug it. I'm glad it wasn't a rusty screw as they can sometimes come up the same. I believe the reason the FE was so high was because after I got the wheatie out, I was getting some strong and deep iron readings. Trust your E-Trac. It may not be right 100% of the time, but you don't want to be sorry when it's not.

[MNDigger]

The most important thing I go by when it comes to deep coins is the way it sounds and how well it repeats in all directions. I have noticed that the FE number tends to jump around quite a bit when there is also iron present like Dale was saying but it will still sound good which makes me dig. I have been fooled a couple times but for the most part the Etrac does a very good job of telling you it is a coin or a coin with iron near it.

[Epi-hunter]

I have to say that I have been fooled more than a couple of times on DEEP iron.

The Fe numbers jumping consistently (key word) into the 20's suggests iron and not a good target. With a good target you will get some fluctuation, and even occasionally the Fe number will hit the 20's, but most of the Fe and Co readings will fall close to what you expect. For a really deep target it can fluctuate quite a bit, but as you continue to swing over the target from all directions, you will mostly see numbers that are consistent with a good target.

I found a barber dime the other day that was the deepest hole I have ever dug. It had to be at least 12 inches. The numbers were actually pretty jumpy, but I could hear the high tone (broken, but there) in all four directions, and the Fe number did not consistently hit in the 20's. But only once in awhile did the numbers actually hit 12/42 (the Co number never did hit the 45-47 range I expected). However, it would consistently come back to 12/40-42 or somewhere close, from all four directions. I hope that describes it reasonably well.

My experience with a dime at, say, six or seven inches is that the e-trac will hit solidly on it. If you see numbers jumping into the 20's you are likely dealing with iron, or iron masking a good target. You can get a nice high tone with the iron, but usually it will be even higher than you would expect for a silver coin, and you won't be able to isolate the target in the same place from all four directions. With deeper iron, it is trickier, because the tone can sound much like what you would expect.... but the Fe numbers will jump consistently into the 20's and usually it will null from at least one direction.

[OkieDigger]

I think the jumpy high FE numbers are really going to depend on the soil type you're dealing with also. A dime at 12 inches would be a tough find in these parts due to the medium to high soil mineralization. It keeps me from running a high gain.

[Epi-hunter]

I think the jumpy high FE numbers are really going to depend on the soil type you're dealing with also. A dime at 12 inches would be a tough find in these parts due to the medium to high soil mineralization. It keeps me from running a high gain.


Good point. I have the same problem in my state. I had the sensitivity set in the high 20's, which I can't do in KY usually.