[Hallicrafters] SX-28 hum

[Roy Morgan]

At 07:35 AM 10/17/02 -0700, Jon Miccolis wrote:
>it suddenly went to a loud hum (electric razor like).  The hum persists on all
>bands and remains even when the volume and gain are at zero. ...
>Does the "hum" problem seem more symptomatic of C51 and C52 A-C line bypass
>caps,


No, in fact you should get rid of them, or replace them: put one from line 
to neutral and one from neutral to chassis.. This is safer than one from 
both line and neutral to chassis.

>C48 and C49 input/output filter caps, or both?

Yes both. All, repeat all, electrolityc caps in that radio are likely very 
tired.

>And if C48 and C49 what
>has been found to be the best (and most cost effective!) replacement option?

Simply disconnect the old caps and mount new electrolyics under the chassis.

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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