Friday, February 12, 2010
HF radio (7) - Microphone
Continuing with the hf radio! Now the transmitting section, let's start from the microphone. Some time ago I managed to buy an table top microphone, not that I didn't had any other one but because it was indeed very cheap. For use with the hf radio it was as simple mater of changing the inner connections to what I wanted: One terminal to the "live" microphone capsule, one for the PTT, both sharing a common ground. Transmission is accomplished by shorting the ptt terminal to ground. Microphone capsule is allways connected so I can use vox.
No big magic here, only sinple switch identification and small changes on the mic/switch board since it had some resitors an capacitor making a DC blocking filter.