5W range
I’ve got an AD8307 board and AVR based power meter display I designed floating around.
Edit found picture of prototype. Can’t find picture of final build
Another A+ in uglyness, thats for sure. RF Klingon building style, never meant to pamper the weak or cowardly.
To hell with the pedantic laws of RF physics.
This thing can probably measure the RF stray of its own little computer used, almost no other power meters are capable of doing this
Some PITA pedantic advice might be a separation of analog from digital part, some brass box shielding, ...
then it could asymptotically converge to a usable instrument.