Fisher F4 and F75 comparisons on undug turf targets

[ziphius]

I had an opportunity to compare Fisher F75 and F4 units side by side after marking deep, high conductors found with my F75. A friend used his F4 to compare the signals between the two machines. Only one machine at a time was turned on for this comparison, to eliminate interference issues. No probes were on either. On targets such as copper pennies at 7 inches or deeper, the F75 gave a good signal and accurately ID'd high conductors as such. The F4 could 'detect' these same targets, but routinely ID'd them as iron. The F4 was adjusted for good sensitivity and volume. I don't know if the difference in depth and ID performance has to do with the fact that the two machines operate at different frequencies (~6 kHZ for the F4 and 13 kHZ on the F75). In theory, lower frequencies should punch deeper (higher frequencies attenuate quicker), but there you have it.

Jim

 

Amazon Forum Fav 👍

Agony and Death on a Gold Rush Steamer: The Disastrous Sinking of the Side-Wheeler Yankee Blade - Grab it through Amazon!