Question about TID'S for Pennies

[chuckciao]

I have been noticing that I am almost consistently getting TID's for pennies in the 38 and even sometimes in the 40 range.
Can anyone explain what is causing this. I am using an X-Terra 705 with a 10.5MF DD, and my ground balance readings are usually between 20-40 in the park I usually hunt. I usually ramp up my sensitivity to 26-28 without any problem.
Thanks
Chuck

 

[Digger]

What year are the pennies? IH pennies and older Wheats usually read in the low to mid 30's. I've had some from the 1860s and 1870's read down into the mid 20's. Zincs usually read 36 - 38 for me, unless the ground is extremely wet and I have my Sensitivity cranked up a bit higher than it should be. DD coils will not provide as accurate TID as concentric coils. And larger coils are not as accurate as smaller coils due to having to analyze more dirt (minerals) when determining the target's properties. HH Randy

 

[mapper65]

I occasionally get 38 or so and dig a penny. Most of the time it ends up being when the ground is wet. There may be other factors involved but I typically don't see the high numbers like that when the ground is dry. When the ground is dry I'll get readings of 28-32. That is with the 10.5" HF DD.

 

[7centsworth]

I get 38 alot I even get a few wheaties in the 40's.

 

[MT_VertCaver]

Over the last two days...in EXTREMELY wet ground:

Zinc pennys--38/40
Copper pennys--28/30/32

I'm using the 5x10 coil.

 

[Beale]

I saw 38-40 on older coppers. on the Zincs it was mid 30's. Beale.

 

[chuckciao]

Thank you to Randy and the others for commenting on the penny TID's. I think that the main three culprits and higher than normal sensitivity, DD coil (10.5 MF), and somewhat moist ground.
HH
Chuck