Currently playing with a CHEAP AD8318 board, seems accurate (CLAIMED +/- 1dB) comparing output of my uncalibrated RF generator, 1-8GHz and -65 to 5dBm. I can only test up to 1GHz though. I could add a small dummy load to extend +35dBm ~20W max.

Trying to use a NodeMCU to have it wireless, with a display for few bucks. Very cheap if you just read out the voltages, but trying to get a nice "instrument" that could be standalone too with a LCD display.

For QRP+, yes Bird 4391M.

Speaking of voltages, I got this reference:

https://dmmcheckplus.com/

or look at  voltagestandard.com

Very reasonable prices, just a satisfied customer.

Giuseppe Marullo
IW2JWW - JN45RQ