[ARC5] nasty hum

[WA5CAB--- via ARC5]

Those are a postwar MWO.  You'll mostly only find them on BC-453-B's and 
R-23A's.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480

In a message dated 05/25/2015 16:10:36 PM Central Daylight Time, 
kgordon2006 at frontier.com writes: 
> Probably the dynamotor. Make sure the dynamotor itself is grounded to the 
> 
> receiver. ARC used two thin copper "straps" at opposite corners of the 
> dynamotor mounting which connected the frame of the dynamotor directly to 
> ground.
>