[ARC5] ARC R-511 Capacitor Failure

[J Mcvey]

 The filter cap on the HV line is the only one I've seen totally short. the others are usually just leaky as hell.I had a similar event with an ARC-5 R-23 . It was running fine for about an hour when all of a sudden i heard the dynamotor bog down and the radio went dead. I was right next to it, so i hit the switch quickly. Fortunately ,there was no explosion. After that, my SOP is open and re-stuff all of the "flower pots". 
Even the leaky ones degrade the performance and cause a higher current drain, so it's better to replace them and be done with it.  

    On Monday, January 28, 2019, 3:46:48 PM EST, DSP3 <jeepp at comcast.net> wrote:  
 
  
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
        
  ______________________________________________________________
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 ______________________________________________________________
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 ac2eu at yahoo.com  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20190128/10d1768d/attachment.html>