One thing that I've found though is the gate of the 555 debouncer is very sensitive, so I used a 1K pull up resistor from the trigger to the +12V bus and I also placed 2 .15uf (.3uf) from the trigger pin to ground. This solved some false triggering complications. The inductance from 18 inches of twisted pair is enough to make it oscillate.
Although I did skip out on the 4th LM3900 that provides +V TX control...

Thanks TOM

-'GF