New F-70 user experiencing false signals

Hi Tom,

Below is a description of two consecutive outings by a new F-70 owner. Other than the usual advice re: hunting in trashy areas, especially burned over areas wrt mineral falsing (including cinders/coal, hot rocks due to fire oxidation), false positives between iron targets, disseminated rusty iron below the surface…and so on…I cannot help the man. He does not live nearby and I have not used this unit.

I have encouraged this fellow to join here as a member and we can only hope. The summary below is all I have to present for your advice. Any pointers would be much appreciated Tom. Thankyou….Jim.

DAY ONE:

Only played with the F70 for about 2 hours.

Thanks to help from an experienced F70 user, I headed to a site where I've dug lots of wheats and IHs.

The F70 setup easily and ground balances extremely well with little effort.

After digging a dozen empty holes with sweet repeatable solid 86-95 signals I decided it was back to the manual and read it again.

I programmed the sensitivity down to 60 and made darn sure the GB was right.

Back out and the same thing---false city. I got the most beautiful solid repeating signals one could imagine. Some even locked on in the 90's. Result..Nada! After removing the top 4 inches of soil the signal corrupts and the hole is empty even at 15 inches deep with soil sifted. A classic false.

Finally I got another signal that repeated like the others but this one read lower (Dime). I removed the sod and it got louder...YES! The deeper I went the better it sounded. I dug down a good 10 inches and found a brass fitting 1/4x3/4 inches in size. Even on the surface it still read the same (Dime).

I should mention I had Iron, Foil, and pulltabs notched out and our soil is loaded with trash.

So, it's a learn the signal game like the Explorer was.

Practice practice practice. We're talkin some time at the coin garden.

I can see this is going to work out and I really like it but I can also see why the first users got discouraged. In very trashy soil this machine sounds like a flock of starlings just before they fly south for the winter.

PS: And too, you have no idea how trashy the soil is where I hunt. We're talkin buildings burned down there 90 years ago. I can walk 40 feet before I can find a clear spot to ground balance. If this machine can work here it can work anywhere.


DAY TWO:

Today went MUCH better.

NOTE: Our ground is still mostly frozen.

Things learned:

1. Our ground balances at between 82-87. If the GB number isn't in that range I balanced over iron and need to find a clean spot and balance again. If the machine isn't balanced correctly it will be extremely noisy.

2. Mode is De (I can't use SL in our high trash areas).

3. Sensitivity setting in our area should be under 80 (I like 70).

4. Notch set on IRON and FOIL

5. Tones 3-H

6. Discrimination 0.

With all this the F70 is still noisy but the good targets usually are loud and clear from both directions and read ZINC TO DIME with a bouncing up into the 90's.

Depth is very good. I dug a hole and buried a zinc penny at 5-6 inches and the coil sounded loudly 4 inches above the ground level. I've never had a machine do that before.

It's a noisy machine in our soil but I'm used to this having used the Tejon for a good amount of time.

If I were to use this machine out in areas with less trash I'd alter these settings.

Sounds like extreme difficulty finding an area to CORRECTLY get a accurate GB. This is very important..... especially in his 'extreme trash' hunting conditions. Good sounding falses are a resultant for GB being incorrect. A site with burned down buildings is a nightmare!...as he so states. Burned iron will cause this problem also...... and with most any detector.

Tom, thanks for your response. I greatly appreciate you taking the time to look at this. Let's hope your input will be a decisive factor in persuading this user to become a member here.

Jim.

I need to clarify something. Very rusty iron/steel IN CONCERT with a incorrect GB is nearly a guarantee to cause his encounterings.

Thankyou Tom.

I will pass this information along, and encourage this well known hobbyist to join here.

Jim.