[R-390] 75A4 PTO Repair

[David C. Hallam]

Can anyone give me advice on the repair of the PTO in a Collins 75A4
receiver?  I have one that has low output and is nonlinear.  According to
the information I have, the output should be approximately 6 V and linear
through its range of 1.955 MHz to 2.955 MHz.  The one I have has an output
of about 1.8 V at the low end and 1 volt at the high end.

What can cause this and how do I correct it?

David
KC2JD/4