sprchng
Well-known member
The frequency shift is pretty reliable for bottle caps but not so great for big alluminum , I usually have to go with tones for it.
I recommend not notching out 97.
I'm sure dirt factors in , and mine has lots of iron , but I repeatedly find myself digging 18 khz 97s and coming up with stacks of clad quarters , especially if the 4khz VDI drops down to 89 or so. Do a test for yourself.
I recommend not notching out 97.
I'm sure dirt factors in , and mine has lots of iron , but I repeatedly find myself digging 18 khz 97s and coming up with stacks of clad quarters , especially if the 4khz VDI drops down to 89 or so. Do a test for yourself.