[R-390] URM-25F Modulation Waveforms

[Roy Morgan]

R-390 folks,

I have a URM-25F which shows distortion in the modulated RF waveform.  The output from the Audio In/Out jack is nice and clean.  The waveform of the modulation on the output RF is quite distorted.  I suspect something amiss at the modulator tube.

Has anyone had this problem?

Also, I’d like to locate a pair of connectors to make a power supply extension cable for testing and maintenance. I seem to remember that the connectors used in the F model are not the same as used in the D model. Any leads or ideas welcome.


Roy

Roy Morgan
k1lky68 at gmail.com
K1LKY Since 1958