F75 Backup Unit?

Lately I have been hunting primary in planting strips / tree-lawns of older neighborhoods. I seem to have better luck in these areas with older coins than I do in parks, but I run into the problem of what I can only assume is EMI. It forces me to significantly drop the sense on the F75 and even then, I have trouble properly identifying good shallow targets that I feel the F75 should be able to handle. Last weekend I decided to dig a weak / barely repeatable signal that jumped all over the VID range. It turned out to be a silver 1943 quarter at barely 5 inches deep. Based on reading other's experiences with detectors, a silver quarter at 5 inches should sound off solidly on even newb detectors.

I decided to send my detector off to Fisher to get the upgrade and have them bench-test it just in case and while I wait, I'm wondering if I should pickup a backup detector to try in that area where the F75 seems to be too sensitive for. Based on my explanation of the area, do you have a recommended alternative?

The older CZ-70's have always been one of the most EMI immune units on the market..... especially with Sens set on '4'. By today's standards, they are a very deep unit.

Tom

What would be the differences between the 70's and the 3D?

The CZ-70's had VERY good batch-consistency from the factory.

NASA-Tom Wrote:
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> The CZ-70's had VERY good batch-consistency from
> the factory.


Not sure what you mean by "batch-consistency"....

Most CZ-70's have nearly exacting/identical performance when compared head-to-head.