I finally got this one fixed. It must have taken a static charge. The fellow
I got this from picked it up in a package deal with an HF-150 that had a
blown 1st mixer. One of the PIN diodes was leaky. Instead of trying to
figure out which one or two or three of four.....................you get the
drift. I replaced all 16 of them with 1N5767 PIN diodes, and the unit is
working well. I measured the broadband insertion loss............right
around 10dB as specified. With the preamp engaged, gain is +3dB, also with
spec. It will make a nice mate for the HF-150. We'll see how long it holds
up............

Pete