[1000mp] PTT Interface

[1000mp@mailman.qth.net]

> Any suggestion for a simple mod to the circuit to allow 
> compatibility with the rear PTT/packet jacks?  

If I were you I would replace the keying transistor with a FET. FET are
controlled with voltage instead of current (comes handy with modern
COM-cards or new notebooks) and when they are open, no no voltage drop
across the D-S, so your radio will see it as a perfect drop. Besides you can
get FET's very cheap (<1$ here), which can switch ampers so you can use it
with older rigs, too. 

Good luck, 73 de Zoli HA1AG