Coil Adapter - White's 6.59kHZ to Fisher F4 Coils

[ArizFlash]

I've seen adapters that will allow connecting Fisher F2/F4 coils to the older White's 6.59 khz detectors. The adapter seem pretty straight forward. I would be interested in trying a Fisher 11" DD coil on my White's XLT and IDX. The frequency match is a little off as the Fisher is 5.9 khz. Has anyone tried this or is the coil design a mismatch for the White's circuitry?

[Skippy]

The F4/2 coils are 6.6KHz. They run at 6.0KHz on the F2 and F4 because there's an extra capacitor (47nF I think) inside the control box.

[ArizFlash]

Skippy, thanks for the response. I'll ask the person making the adapters if it has the capacitor?

[Skippy]

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There's no capacitor because you're fitting a 6.6KHz coil onto a 6.6KHz machine.

[ArizFlash]

Skippy: Sorry I read your comment backwards. I'll buy the adapter and find someone with an F2/F4 coil and see if it operates correctly.

Alan

[Reg]

I have tried one of the F4 coils on a Teknetics Mark 1 and it works fine, so it should work fine on the White's also.

Reg

[ArizFlash]

Reg - Thanks. I'll try it out.

Alan

[ArizFlash]

I bought the Fisher F2/F4 to White's coil adapter and an 11" DD coil for the F4. It works but not good. Detection depth is approximately 4" (10 CM) on a US Nickle and the target ID was way off. I sold the coil for what I paid for it so I'm only out the $22 for the adapter. I guess at this point if i want a DD coil for the 6.59 kHz White's detectors I'll need to make one.

[Skippy]

That's strange, you would think the guy selling the adaptor would be confident that it's a viable conversion.
My hunch as to why it didn't work is that the receive-coil differs. The F2/F4/BountyHunter coils have a very low RX coil resistance, a few ohms. This isn't because they have thick copper wire, or are made to be really low-noise. It's because they have a fairly low number of turns onthe RX coil. This 'low-sensitivity' arrangement is compensated for by having a high-ish gain pre-amplifier. Maybe the Whites coil has a greater number of turns, a proportionally greater resistance, and more output voltage. Just a guess. Seeing as you've sold it, we may never know...

[Silver Dollar]

Here's some info on both;
Whites

F2


White's typically has some resistive coupling from the TX to RX too...

When they say adapter they mean it will plug in not that it will actually work!

[Silver Dollar]

I just plugged a bounty hunter coil into Ivonics Minelab transmitter with no cap and it oscillates at 6.5khz so
the TX should work.

[sinclairuser]

i wonder if the adapter is having an effect on performance, i acquired a bounty hunter adapter, push fit din to screw in mic type(not quite the same as here but never the less), it was crap depth dropped and detector became chattery, i checked the soldering and it appeared fine.
in the end i changed the socket on the control box to the mic type,and put a new type plug on the original coil, after this all was fine with either the original coil or the small nugget type.