BarnacleBill
New member
I haven't really used the 3kHz coil much as I primarily hunt gold jewelry. But I decided to go after some deep silver yesterday so I used the 3kHz. Anecdotally as I traveled along I noticed that it was responding very poorly to low conductors, that being square tabs that were on the surface and wads of foil. I was struck by the thought that this ignoring of foil might come in very handy for a park hunter.
This morning I decided to concoct an experiment to test my field observations. So I enlisted my daughter who loves to do crafts to make a "plate of shame" for me. It's a paper plate that she used a glue stick to attach small pieces of aluminum foil on to act as surface foil slaw.
I then went out into the front yard and buried a copper penny at a measured 6 inches. Because of the nature of the sand/gravel soil, a copper penny is barely ID'able by most machines at this depth. I used an X30 with 7.5kHz, X70 with 3kHz, and Fisher Edge 8 inch 6.5kHz to run the tests. All machines were GB'd, noise cancelled, and Sens set to about 80%. All machines could only ID the coin correctly ID by being spot on over the target with a specific optimised sweep speed.
[attachment 41585 gnd.jpg]
The "plate of shame" was then moved into and out of place several times with each machine. Only using the 3kHz coil would there be any consistent indication that a higher conductor was below the foil. There was some averaging present as expected but the ID was definitely way above foil.
[attachment 41586 plate.jpg]
I think more field experience is needed to confirm what I'm seeing, but it presents some interesting possibilities for park hunters.
HH
BarnacleBill
This morning I decided to concoct an experiment to test my field observations. So I enlisted my daughter who loves to do crafts to make a "plate of shame" for me. It's a paper plate that she used a glue stick to attach small pieces of aluminum foil on to act as surface foil slaw.
I then went out into the front yard and buried a copper penny at a measured 6 inches. Because of the nature of the sand/gravel soil, a copper penny is barely ID'able by most machines at this depth. I used an X30 with 7.5kHz, X70 with 3kHz, and Fisher Edge 8 inch 6.5kHz to run the tests. All machines were GB'd, noise cancelled, and Sens set to about 80%. All machines could only ID the coin correctly ID by being spot on over the target with a specific optimised sweep speed.
[attachment 41585 gnd.jpg]
The "plate of shame" was then moved into and out of place several times with each machine. Only using the 3kHz coil would there be any consistent indication that a higher conductor was below the foil. There was some averaging present as expected but the ID was definitely way above foil.
[attachment 41586 plate.jpg]
I think more field experience is needed to confirm what I'm seeing, but it presents some interesting possibilities for park hunters.
HH
BarnacleBill