[Boatanchors] Resistance values of power supply chokes

[Drew Papanek]

On the topic of  an HQ-129-X  Ken Hickman wrote:

>Problem is a loud hum or horn sound and the three 10 Mfd. 450V
>condensers all come thru with flying colors on both the "Z" meter and the 
>N.R.I. R/C Tester.

>My next effort will be to substitute another audio output transformer (for
>the original in the rcvr).

Perhaps the hum could be caused by high heater to cathode leakage in one or 
more of the tubes.  Have you tried swapping out tubes?

Another cause could be a high resistance connection to chassis ground, 
particularly when said connection is shared by a heater return.  Sometimes 
moving heater returns to a separate chassis connection can help.

Old electrolytics are always suspect, despite what some test equipment may 
tell you.  You might try bridging one or more of the filter caps with a 
known good cap and see if that affects the problem.

The output transformer is not a likely cause.

Drew

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