This amplifier takes advantage of the proliferation of surplus cellular 26v RF boards. It combines two 150 watt boards using 3db hybrid couplers. I made the couplers using FR4 on the input, and .062 PTFE on the output.

Input power required for 300w out is about 25w.

Supply voltage needed is 26-28v @ 23a.

It has full relay sequencing, including transverter and radio control lines, and a low loss transfer switch.

This coupler has to handle a lot of power, so I used .062 PTFE to keep the losses and heating very low.