I'm in the process of building a Jaycar Mk II kit, but have a faulty coil and am waiting for a replacement from Jaycar so can't finish it just yet.
In the meantime, I've got hold of a Yaege FC-1 to help me set up the theremin, ready for when it IS finished.
I understand that you use one of these frequency counters, and I wondered how you use it to measure the frequency of the various coils. Unlike the bench frequency counters I've seen before (with probes), this little handheld device only has an antenna. I'm thinking that it could be tricky to use it in the cramped confines of the Jaycar's PCB.
Thierry, do you have any tips please?
Yes, you should do the same as I did some years ago:
Unscrew the antenna. You'll find a small UHF plug. Take then the frequency counter to a local electronic component store, show them this UHF plug and buy a fitting adapter from this to BNC. The mine was 2.30€ and since then I use the Yaege with normal probes.
Yeah - I did the same.. My counter has a male SMA connector, and SMA female to BNC female adaptor cost about £3.50..