[Milsurplus] AN/URM-25 questions...

[Kenneth G. Gordon]

I have a "D" model which I have been using to align and service VLF 
radios for a while. I bought it a couple of years ago from Fair and never 
used it until a few months ago.

Overall, it seems to be a pretty good sig. gen. However, a few days 
ago, I tried to use it to service an HF radio and discovered that, at least 
on frequencies above 9.5 Mhz, it was very unstable and the signal 
contained noticeable hum.

1) Is this a characteristic of the URM-25 or do I have a problem I can 
fix?

2) If this is not a common characteristic, are these problems common?

3) Is there some document somewhere which lists these common 
problems and their fixes?

I really don't want to re-invent the wheel if this has been documented 
somewhere else.

BTW, I DO have a manual for it.

Ken W7EKB