F75 LTD Observations

Got home from relic hunting (just got a couple of 3 ringers today) and after a rest I went out in my back yard with the F75 LTD. My place is built on the site of an old barn so iron trash is plenteous. I decided to hunt in quiet mode so I set it up in dE mode, disc 10, sens 90, 4 tone. Got a 2 way signal at quarter level. At 8 inches deep my Sunray probe showed the target squarely in the center of the hole and still buried. My Lesche digger was about an inch up on the red handle in the hole at this point. On my next dig the target was out. I thought for sure it would be an oldie but it turned out to be a 1981 memorial cent lol. They graded the site here when the house was built so that kind of explains it. Still, I was impressed with the depth of the memorial at those settings on the LTD.

After retrieving the coin I ran disc down to zero and checked around the hole. I had iron hits in two quadrants next to the hole. One was about 8 inches from the hole and the other was about 12 inches away. Both were solid and loud.

I had a 3 ringer in my pocket, so I dropped it in the hole and replaced the dirt plug to do some testing. Surprisingly, the bullet didn't seem to signal as cleanly as the memorial cent did. It was breaking up. I went to bP mode and was able to get a solid two way on it, IF I KEPT THE COIL ABOUT 2 INCHES ABOVE THE GROUND. If I scrubbed the ground the signal started breaking up. The manual says that you lose some separation if you scrub the ground in bP mode. I clearly observed this happening today, so keep that in mind if you hunt in trashy ground in bP mode.

I'm wondering why the bullet did not hit as solid as the penny when I was in dE mode. Bullets have a lot more mass, and are lower conductors which is supposed to be an F75 strong suit. Anybody got any ideas on this?

Very strange. Difficult to speculate on this one. I do know......even in mineralized ground......there may be times when a few tiny flecks of rust/iron .....above the intended target........may help boost signal strength (certainly not the ID)......and report the target. This holds true only for the T & F series platforms. In your case.........you had a open hole (air-gap).......so I can only surmise the adjacent mineralized dirt around the hole 'looked' like a better target to the detector.

In Florida's inert dirt.....whilst in bp mode......a coil air-gap above the ground is not beneficial nor detrimental.

NASA-Tom Wrote:
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>> In Florida's inert dirt.....whilst in bp
> mode......a coil air-gap above the ground is not
> beneficial nor detrimental.

Tom,

As I said I had iron trash in two adjacent quadrants around the hole. I would think having the coil at the right height to achieve good target separation would be important in bP mode whether the ground was mineralized or not.

True, but in most cases.....the closer the coil is to the target (especially the desired target)...the better the chances of detection and/or unmasking.