The K1JJ 4 Relay Sequencer

[ke1gf]

This thing is a must have for the PDM experimenter, it solves alot of problems and provides complete electrical isolation if nessessary.


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

[K1JJ]

This thing is a must have for the PDM
experimenter, it solves alot of problems and provides
complete electrical isolation if nessessary.

FAR OUT, Bill!

This is the first time I saw your new setup.

Yes, the false triggering was an issue here too and I did
something similar to you. We'll have to compare notes
so that we can get the schematic published.

Yes, it sure helps to smooth out the rig.

Later OM.

Tom, K1JJ