FB Artur ! I suggest to put a directional coupler in the new extra space by the output trace !
Thank you for a good review. I bought BLP9G0722-20G in China at $ 9/piece. They will sell me the original transistors:
I now change the design and put in a new housing like my TRV. Now you can make 12V power supply because there is a step up converter with potentiometer regulating from 12V to 30V.
update...changed 100r preset to 1k preset to get more range...i can set bias now to 450ma or more but i stop at 450ma....can hit 20w avg fm in ssb mode "whistle" i see 22w peaks...max current is 1.6a at 28v...freq 2320mhz at 2400mhz there is about 1.5db lower. I can say this is working great now but the fan running on heatsink makes a BIG difference and keeps bias stable. these readings are after abusing 5mins key down in FM..i risked it as i have 10pcs spare ldmos on order from digikey i only managed to kill 1 so far after i slipped the meter probe on bias track and hit drain track they are so close...the magic smoke was very quick to release and burn €20 device but good experience for when using €200 device ! SP3OSJ FB thanks for PCB although you have made it to fit in a specific case I would personally have made a generic PCB with more spacing and easier to fit M3 screws with more spacing but you had to adapt to the wifi case you had so understandable
I have build your PA with your PCB, but I run into some problems. The provided output match has a maximum at 2.1GHz and falls down -13 dB to 2.4GHz. The design looks like the test circuit for 2.1Ghz from the datasheet. I was able to get a much better match for 2.4GHz by changing the existing ATC caps.
Your PTT need DC from the input. I have changed it to external.
You have covered the backside of the board with solder mask. It has has a thick one. I have scratched off most of the solder mask to get a better thermal contact to the heat sink.
With this modification i get nice 16W at 2.4 GHz.
73, Peter DC2PD
I have changed BIAS resistor to 27r and replaced divider to ground (ex 110r*) with a 100r preset. The highest I am getting the BIAS to go is around 360mA. With about 700mW I seem to hit saturation and I am getting around 16W in CW mode. HP meter cannot read PEP. Do you think I should stop here and not push my luck ?
This is a test setup. The VCO is missing and a standard oscillator is beeing used to test operation. The good news is that a 10 MHz output is available !!!
Has the design and code for GPSDO this been published anywhere ?