For fast recovery diodes and bridges, look in your mouser catalog under
rectron, or ST. They both make gobs and gobs of the beasts.

If the unit was ok, and now suddenly buzzes, it might mean that the
bridge has one diode that is breaking down. First try replacing the
bridge with most anything silicon with at least 2x the HV as a PIV.

If that doesn't work, then look at the cap that goes from the power line
to the chassis. These are supposed to keep power line noise out of
the insides of the chassis. They also take a beating, and are usually
cheap wax paper caps.

Another thing you can do is run the antenna of another radio as a coax
and a 1-2 inch loop of a few turns. bring this loop around to various
parts of the SX, and listen for the noise. If your SX can hear it,
another receiver should also.

-Chuck

Mike Knudsen wrote:
In article , Chuck Harris
writes:


This can be solved one of two ways:

1) add a series resistor to each each diode to limit how much current
can flow, 100 ohms, or some such. (Note, one for each diode!)


Would shunt caps help? What if it's a bridge unit and I can't get in series?
Replace with discrete diodes and Rs?


2) switch to fast recovery diodes.


How would these be specified in a catalog? "Fast recovery power diodes"?
Thanks, Mike K.



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