K7ITM wrote:

Hi Tom

A part of a solution: since pretty much any commercial mp3 player will
handle stereo, assuming sufficient channel separation, put your desired
voice on one channel and a tone on the other channel. Then use a

I did think of that too, and should be pretty easy to build with a .wav
editor on any PC. My only concern is about channel separation in the
pocket player, and whether MP3 compression would throw away the tone or
not.

Because of MP3 compression I think the tone should not be chosen either
too high or too low.

I'm not sure if it would be any value, but you could also use different
tones to key different things; standard DTMF would be one way to do it,

Well, walking uphill with antenna, RTX and battery (one each) is tiring
enough - that's about 3kg -, having even more radios is not for me. :-)


Thanks for your suggestion,
Paolo IK1ZYW