My V3 runs quite smoothly in the 2.5KHZ, 7.5KHZ and triple frequency mode. However once I run it on 22KHZ only it gets terribly noisy giving me false signals all the time. Even not moving the coil will constantly produce sounds / false readings.
I always do a manual ground balance and tried turning down the sensitivity settings dramatically but it didn't help.
Once I switch to a different frequency than 2.5KHZ the machine gets stable again?!
That's a pitty as 22KHZ is what I am looking for as it is most sensitive to small items like thin coins etc.
Could my coil be broken?