This is just a brief update on an earlier post, related to the power meter option for EIP counters, EIP Power Meter Upgrade. The current 545A came without any options, even without GPIB, and I was not quite sure if the firmware power meter option firmware would work, even if no GPIB option is present. Well, easy enough, put it to test.

It didn’t take much, a few (rather old 2516, and 2532) EPROMs, a resistor, some spare ICs, and a few inches of solder…

Here, the result: all working just fine, counting away at several GHz, and power reading appears to be resonably accurate. I would not substitute it for a proper power meter, for calibration purposes, but the power meter option is a handy feature for any quick test and confirmation.