Remember about 17 years ago when the Fisher 1236x2 hit the market? I had one I ought to know.
You could wave big rusty square nails in front of the coil and you would hear not one peep out of the 1236x2.
The Fisher F44 has been built the same way!
With the 7" round concentric coil and in the Jewelry Program with iron notched out...
I waved a rusty 4" nail in front of the coil and not a peep out of the F44.
Next I waved this old rusty gate chain in front of the coil and not a peep out of the F44.
Next came the big test...
I waved this old rusty iron washer about the size of a half dollar in front of the coil and again not one peep or beep out of the F44.!!!
And the F44 goes deep... ask those relic hunters over on You Tube.
Fisher has done it again... It must be that double derivative programming:)
Fisher you Rock!