> We have been experimenting with building CTCSS Units using the > 567 Tone Chip and good components, i.e. Caps, multi turn pots etc. > The stability is not good in my opinion.
For encoding, there's a million PIC-based solutions on the net. I designed my own, using a different PIC (12HV615) to reduce extra components to minimal: it has a built-in voltage stabilizer (no 78L05 needed, just a resisitor), and using bitstream D/A so no external D/A network neccessary. Using SMD will make it really, really small and cheap. I can't publish the details yet as we plan to use the kit as a fundraiser for the local amateur radio museum. For decoder, check out http://www.mcarcoh.org/ke8rv/photo-sd.html, specific the comments about his controller. I exchanged mail with the designer and his design is facinating, though not publically available, which is understandable. I have good experiences with the TS-64 in my repeaters. Note that you can configure it to encode and decode CTCSS at the same time, so it's possible to re-generate CTCSS at the repeater output. 73, Geert Jan
