RX-TX unit with double SWR bridge and sequencer

TX-RX unit is intended to provide the switching of power amplifier between receive and transmit modes.
Input signal is PTT line from transceiver.
When PTT input goes low, the relays directs the signal from transceiver to PA input and from PA output to antenna through LPF. When PTT is high (RX mode) the antenna is connected directly to transceiver.

3-event sequencer with 16 msec delay provides correct timing even if PTT control signal to amplifier disappears while transceiver stay in TX mode.

It has two SWR sensors (Tandem-match) onboard. First is connected between PA output and LPF input to recognize the situation when wrong or no LPF band selected at all. Second is connected between LPF output and antenna to supply the voltage for SWR and output power measurment by any device.

Two pairs of FWD/REF outputs : one to control protection device, second to measure SWR and power on PA output.

Max power level : 1250W SSB and CW modes.

Frequency range: 1.8 - 54 MHz
PCB size 72(w) x 158(l) x 25(h) mm