[ARC5] ARC R-511 Capacitor Failure

[DSP3]

Cliff,

  As you have noted, Type 12 stuff generally runs a long time.  That 
said, after some 50+ years, and depending how the equipment has been 
stored and/or used (READ: NOT USED), things may well go south.  Gear 
that I intend to use on a regular basis and depend on it, I re-cap the 
major capacitors, especially electrolytics.  Design and chemistry has 
come a long way since the 50's.  ARC used top notch parts, caps 
included, but time and tide take a toll.

Jeep K3HVG

On 1/28/2019 2:46 PM, Cliff Miller wrote:
> I recently acquired an ARC R-511 Type 12 receiver, 190-550khz, with 
> dynamotor.  The receiver appeared used but relatively clean. After 
> some initial checks, I serviced the dynamotor bearings and then 
> applied power. The receiver worked long enough to run up and down the 
> band a few times looking for my local NDB.
> After several minutes there was a loud bang and the radio actually 
> hopped off the desk an inch or two.  The dynamotor kept running but I 
> shut things down quickly.
> C-634, a 5mfd dated 2-56 on the high voltage bus, had expelled its' 
> contents inside the radio.  Nothing else appears damaged.
> I've run other Type 12 radios for hours without re-capping.  What's 
> the history with these?  Comments welcome!
>
> -- 
> Cliff Miller W4HGR
> cliff52 at gmail.com <mailto:cliff52 at gmail.com>
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: https://www.qsl.net/donate.html
> Message delivered to jeepp at comcast.net
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20190128/fe4bb2ca/attachment-0001.html>