[ARC5] Dynamotors and receivers

[WA5CAB at cs.com]

A lot of BC-453-B's got the same MWO 

In a message dated 06/09/2013 06:38:51 AM Central Daylight Time, 
aaf-radio-1 at aafradio.org writes: 
> On 6/9/2013 1:17 AM, Kenneth G. Gordon wrote:
> >Tonight, I tested an R-25 receiver I have been working on here by 
> powering
> >it with a DM-34 dynamotor. I first cleaned then greased the dynamotor's
> >bearings with that grease that Mike Hanz recommended.
> 
> If you aren't already doing so, you might want to keep the tube of 
> grease wrapped up in some paper towels and a plastic sack in your 
> freezer.  It has a high oil saturation compared with other greases and 
> will bleed on your shelf more, especially if you keep the tube in a 
> vertical position.  Lowering the temperature and laying the tube 
> horizontally will reduce that tendency.  In the tiny amounts present in 
> a high speed motor bearing, the separation rate is optimal for 
> lubrication, according to the Mobil engineer that I talked with about 
> the tendency.
> 
> >I was using clip-leads to connect everything together with. At first, 
> there was
> >some minor "crackling" noticeable in the audio, but when I connected the
> >frame of the dynamotor to the chassis of the receiver with another 
> clip-lead,
> >the crackling disappeared.
> 
> Heh, heh...great minds think alike, Ken... :-)   ARC began adding a 
> small pair of copper straps to the postwar receivers on diagonal shock 
> mounts to accomplish essentially the same thing.  I think they began the 
> practice with the R-23A in 1945, so they must have noticed the same thing.
> 
>            73,
>   - Mike  KC4TOS

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