PTT Sequencer

Sequencer 1st generation 2008 - ALC power supply separately

Block diagram

Timing diagram how I am using that

Schematic diagram and PCBs

View to open box with sequencer. Switching PS 230V/15V-4,5A supporting Relays in antenna, PAs, LNAs. Relay in each position is possible to setup for switching to ON or OFF, according of request. Also on the PCB is possible to choice if relay on PCB is in ON or OFF position. This solution giving lot of possibilities. 
Front panel with control LED diodes. Last in row from left is read LED diode and showing total PTT is position ON AIR
Rear panel with 230V socket and two RCA connectors. One of them for PTT by grounding, second one for PTT present by TTL or +12V on. Four different color RCA connectors for ANT relay - yellow, LNA-green, PAs - white, PTT of TRV & TRX - red.
Sequencer 2nd generation 2018

TOP view of PCB

Bottom view of PCB


Sequencer schematics


2nd generation of my sequencer including also negative power supply for protecting TRV trough ALC connection in to TRX. During RX period is -3V presented on ALC input in transceiver. First, you never have problem with spikes or peaks, second, you can squeeze CW Key or Mic, but TRX has zero RF on the output.