Looking for help with an HP 8554B spectrum analyzer plugin

[Fred Abse]

My 8554B says "Maximum 10 dBm" on the front in big red letters.

There's probably a reason why they put that on the panel.

That's the absolute maximum safe input.

10dBm is about normal for that age of analyzer, but they're not usually
usable up to that, the figure to look for is the input level for 1dB
compression. Above that, the analyzer wil start generating significant
spurii of its own. As a rule of thumb, put another 10dB attenuation in,
if everything drops by 10dB, what you see is what you've got. Anything
that drops by more than 10dB is probably an artifact of the instrument.

 

[Pete KE9OA]

I think it must go back to what devices were available at that time; my
8558B specifies no more than +30dBm.

Pete

 

[PhilW]

you might be better of using a modern SMD dual schottky diode, better
match, lower capacitance etc. You will have to devise some neat way of
fitting them in. Circuit is in series config so try HSMS-2814, or 2 in
one package HSMS-2815. Try Farnell or Newark? for these parts.Yes the
service manual says you need a matched pair of
1902-0385. I suspect a pair of 5082-2835 would do OK also.