25W-PA-for-Tetra

This is a second stage of RF amplifier where the first stage is PA with the TQP7M9106.

PA Operational freq. 380MHz - 460MHz

Tetra up to 10W.

To run the PA properly the RF input must be up to 18~19dB, if the rf power is above that value then you need attenuator after TQP7M9106-PA RF output and this PA RF input.

The RF in/out capacitors must be with tolerance up to 0.5% max. You can find the values for each one in the BOM file.

The schematic is taken from AMPLEON-BLP9LA25S datasheet, the PCB is identical from the datasheet with added BIAS power supply with voltage adjustment and current limiting.

Testing the PA, the RF-in not connected, connect proper dummy load on RF-out, Power supply 12V~13.6V/5A, adjust the BIAS voltage to 1.8V.

Connect the PA RF-in to TQP7M9106-PA RF output, run Tetra BS and monitor the RF signal (easy way with sdr-receiver and sdr++ with tetra demodulator, follow the signal quality and constellation)...

... if needs any corrections first try with BIAS voltage adj. and if needs more adjustments then add the attenuator to low the dB input and again with BIAS adj.

This PA is OPEN PROJECT and is not tested yet but you can try to build and test it, if works then will be usable for radio-amateur community and specially for Tetra.