[R-390] test equipment question

[Tisha Hayes]

I know that this is broaching on heresy to mention this;

I found the URM-25D to be less than helpful when compared to a good signal
generator. It is drifty, the impedance matching module is a joke and it is
hard to get repeatable results when trying to chase the performance dragon.

But; if you use a good frequency reference (like the 100 KHz calibrator and
that is not waay off and WWV) you can get darned close to being on
frequency.

If you dare to dabble with the compensation screws on the PTO to correct
linearity you need a much better frequency counter and signal generator. Of
course, gettting used HP/Agilent equipment will cost you more than any one
radio would ever sell for. You can find a really decent HP 400 series VTVM
or a Boonton that would do an excellent job on measuring RF levels for a
song-and-a-dance.

The original maintenance manuals were written around the inherent
limitations of the test equipment available at the time (URM-25's). While I
try to keep the filaments glowing and avoid transistor/IC based radios in my
setup I do use more modern test equipment.
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