3-D set up that worked well in iron pit---Why?

Used the 3-D today at relic site with 10.5 inch coil, salt mode, sens just below 5, GB 5. I found 6 fully intact suspender buckles in a short time. I was very surprised because I had virtually no luck with the 8 inch coil. These targets were from 1-2 inches deep. They are the kind I want to find here. I have found several with small 75 coil, but I also find many small partial pieces of relics or alot of shoe fasteners at deeper depths. Keep in mind that I have removed over 300 square nails, machinery pieces etc that came out of same hole with good stuff using the 75 with the stock coil. I was using a slow sweep speed and listening for any sound other than low iron grunt or high iron false. I set it in salt mode so I would not have extra high tones to worry about. I wonder why the 10.5 coil smoked the 8 inch coil using these settings on the good shallow targets. I know there was still alot of masking but this cherry picking of remaining large buckles was a surprise to me after 4 months of using Explorer, F-75 stock coil, F-75 small coil, Sov GT with Sunray probe as main coil. There is still iron in the area I found these but was able to hear the good tones come through. I had been to an old school with 3-D with 10.5 coil and was on my way back by the site so I tried it for a few minutes not expecting to do very good and was suprised at the success of finding fully intact buckles with it at such shallow depths. I know it works and will go back when I have more time to use that set-up but I would like to know why it worked so well.

Brad

Brad,

The large coil on the CZ has a unique "wrap-around" effect..... and can produce targets that are located at fairly shallow depths,,,,that the 8" coil may not see DUE TO lots of smaller pieces of (usually iron) targets on top of the good non-ferrous target. The larger coil is desensitized to the smaller iron (masking) trash targets..... where as the smaller coil is more sensitive to the smaller targets. Some time ago.... I thought I wrote an article pertaining to exactly this phenomenon. I also recommend reading "Head-to-Head Comparison Testing". Different coils can see targets differently.