I got a HP 436A power meter with a 8481A power sensor. Both the sensor and the meter work fine and very accurately.
Today, I just wondered, whether it could be possible to reverse-engineer the power sensor interface, and make a own power sensor using a diode detector. I have already made several diode sensors, they work fine from a few kHz up to GHz, no problem, but it would be really comfortable if it was possible to connect the homebrew sensor to the 436A power meter and directly read off the dBm. Has anybody ever tried such a project? in my opinion, it should be possible because the schematics of the meter and the sensor are both available.
Apparently, there is a chopper inside the power sensor; I think, this chopper could be built e.g. with analog multiplexer ICs or similar. However, I wonder how the meter converts the voltage to the dBm reading. I think this could be the biggest problem. Can somebody explain it a bit more in detail?
I think it should definitely be possible because there are diode power sensors for the 436A, like the 8481D or similar, and the meter works with these.