On Monday, tested a 1998 (Rev. 0) RFPD originally found in Crackle (serial #010). Looks like it was first resonant at 24.493 MHz, but was later tuned for 14.75 MHz. I used the AG4395A network analyzer in CTN following the procedure in the previous ELOG post, splitting R output into the test input of the RFPD. Driving at up to -10dBm, couldn't see any resonant feature in the TF below 150 MHz. Tuning the inductor L1 made no difference. The regulator (U3 and U4 near bottom right in picture below) outputs were nominal.
I borrowed a flat response (DC to 125 MHz) PD from CTN lab (New Focus 1811) along with its power supply for short term use.
Below are some photos of the aformentioned RFPD. I added some kapton to keep dust off the PD.