The device is £64 including postage and the rest will be 3 x 12v 30a power supplies in series and turned down to 10.6v, a huge heatsink and a big fan!
I will post more details as I progress.
Power measurement is via a 30dB high power directional coupler and my dummy load will have to be a patch antenna out the window as I don't have a dummy load that big!
The pcb's are fitted to a 3mm copper pallet fixed to the heatsink with 16 screws
I will post pictures on Facebook in "OSCAR-100, QO-100, Es'Hail, satellite operators and experimenters"
Just been doing some tests up to 150 watts output as I'm PSU current limited and have found that a temperature compensated bias supply is to be advised to prevent run away with a fixed bias voltage.
https://www.ampleon.com/documents/appli ... _10032.pdf
Only problem I had was with RF getting into the sense transistor - a bit of screening and filtering fixed the problem.
I also soldered the PCB down to the heat spreader around the FET and RF connectors.
I also had to snow flake the input match as it was centred on 2450MHz .
One slightly odd effect I've noticed is the proximity of metal (or even a human hand !) causes the output power to vary as much as 30 watts when running at 150 watts out - I may have to install a shield round the PA.
The output coax gets quite warm !
I have an 868MHz telemetry system built in for remote monitoring and control.
Over all very pleased so far and hope to be air testing in the next few days.