Correlate and Caches via v3i

Hi,
I am holed up because the ground is frozen, and being bored, was air testing my stock 10" DD on my v3i the other night. When I had a particularly startling discovery. I had my detector set to 5 band, 3 frequency, correlate with a -94 wrap and a 28 span. And when I took a whole handful of silver coins and swept them, my detector completely discriminated them out. I got no signal at all. What was happening is the 22.5 and 7.5 frequency was wrapping around to the negative and I had to adjust my span all the way to -93 before I could get any kind of signal. Even getting a signal the 22.5 and 7.5 frequencies were still show up as red and negative on the spectragraph. Of course you don't have this problem in best data.
My conclusion is be careful when using correlate to discriminate in ground infested with iron because you could be missing that cache of coins or even a coin spill. I just thought others might be interested in my findings.

FreeMindStuck

In general multiple high conductive targets in close proximity (A pile of coins) will confuse the filter response on most detectors, and be discriminated out by by typical coin patterns. You can check this out for yourself using a roll of quarters. Holding the roll by the ends between your thumb, and forefinger pass the roll under your coil several times. Most will be surprised by the results. Add a little mineral strength, and depth to the picture, and in most cases it will look like junk. Relic modes, and mixed modes will do a lot better job at picking out these type of targets. The biggest misconception about cache hunting is that when being detected it will give a high conductive response.

Great subject matter FMS!

this is the reason I've always ran my dfx in best data

i've heard of similar issues with the etrac , to many silver coins under the coil and it will also discriminate them out .

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Originally Posted by del

this is the reason I've always ran my dfx in best data

i've heard of similar issues with the etrac , to many silver coins under the coil and it will also discriminate them out .

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Yep, too many silver coins will not respond audibly, but what is shocking is that it occurs with an open screen (no disc) :shocked04:

Interesting. I missed a large old wheatie spill once while in Correlate mode. The DFX just blanked out. I blamed it on wrap around from the ton of iron at that spot just washing out the top end of the VDI scale. I hit the coin spill the next week when the only change I had made was to switch to single frequency (3kHz) and turn Normalization off to get those high VDI coins to hit lower on the VDI scale. This was a small area right in front of the front steps so I know the coil went over it the first time. Hmmm....I never considered that the pattern of the target might have had something to do with it.

If you are hunting for targets that may wrap around the corner so to speak it make be worth while to make sure that all the VDI's in that area including +95, through -93 is accepted. As pointed out in the other post best data or using single freq. with normalization off will help with the wrapping around the corner,

rcsnake