The 23cm mast top box is now almost completed with many thanks to Anthony for help putting it together. The unit now comprises an SG Labs transverter (2W output( and a PE1RKI amplifier. With 2W input the amp gives 40W output, with a 6dB pad on the transverter output the 28V amplifier gives 10W output for 500mW in. This configuration will give me 10W for the RSGB UKAC AL section and by removing the pad I can have 40W for UK Microwave Group contests.
The RF relay is a little Swedish made GHz SMA relay (branded Philips) whilst DC voltage is sequenced to the relay, amplifier bias (12V) and the the transverter PTT using a W6PQL sequencer and a band of 12V miniature relays. The 28V main voltage is supplied to the amplifier contentiously.
At the base of the mast is a small control box containing the PTT interface, 28V PSU (DC to DC up convertor from 12V) and the 12V supply. The control cable provides: 28V, 12V, PTT, Ground, and a Serial connector for arduino (not yet connected). In due course there will be an Arduino Nano in the mast top box and another in the control box. The Arduino will provide the following information from the mast top box to an LCD screen on the control box; 28V and 12V voltage monitor, current drawn by amp on peaks, Transverter Fwd Power, Reflected Power, SWR, Amplifier Power Output.