[ARC5] Dynamotor noise in SCR-274 receivers

[Tim]

Try running a short ground strap from the dyno frame plate to the radio
chassis - effectively paralleling the DC chassis ground connection to the
dyno.  Seems unnecessary but it cleaned up my system dyno noise.
Tum
N6CC

On Sun, Aug 24, 2025 at 6:36 PM Matt P <mgpaulonis at gmail.com> wrote:

> Getting closer. I completely cleaned and lubed the bearings of two command
> receiver dynamotors and get overpowering dynamotor noise in the audio. All
> three receivers have new caps and work just fine with an outboard power
> supply with 24 V AC on the LV and 60 VDC on the HV when not plugged into
> the rack. Would this be a strong sign that the original chassis wiring in
> the receivers definitely needs replacement?
>
> Matt
> W2NS
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