5.75" concentric coil preformance

[Koala]

What sort of performance can I expect from the coil on a Tesoro Bandido II Micro Max with a 5.75 coil

A Canadian dime and UK silver six pence are air testing at 5" does that sound about right ????? That's in discrimination mode


However with a very fast swing the distance goes up to 6" and if I lower the coin towards the coil instead of across it the distance goes up to 6.5"



Does this sound about right before I close the coil.

[Koala]

No idea what's going on. Just come back to the same coil / detector and straight from switch on its jumped to 8". Would be well pleased with that same as my IDX or even a touch more. Not sure why it alters 2".

At least I know what's its capable of.

[Oatz]

Very interesting! I just started reading into building coils and was hoping to make a 5.75 copy for my Bandidio II Micro Max.

Please post your findings and maybe some pictures?

-Oats

[Koala]

The little silver coin next to 1 pence UK coin tests at 6.5" flat to the coil. But impressively 4.5" when vertical to the coil. On my IDX and 8" coil it is almost undetectable when vertical.
Connected the TX up to the detector and adjusted the turns so the frequency was 10 kHz then connected the RX up to the TX on the PCB and adjusted the frequency to 10.5 kHz

Wire 2.8mm

RX 3" and TX 6" came out about 2.7 and 5.7 after the groove was made

[Oatz]

Thanks for your help!