[Collins] Fwd: humm

[drleborgne at aol.com]

Thank you all for the expert advice.I found the culprit: one of the PA"s 6146A? causes a 60 hrtz sine humm deteriorating audio. Seems to have a grid leak and a heater to cathode leak as Jerry suggested. I bought a replacement in Ebay

and will let you know the results of the smoke test.

Kind regards Martin.? (pd. the net works)


-----Original Message-----
From: Dr. Gerald N. Johnson <geraldj at storm.weather.net>
To: collins at mailman.qth.net
Sent: Fri, 10 Apr 2009 3:09 pm
Subject: Re: [Collins] humm




On Fri, 2009-04-10 at 12:48 -0500, Tony Sokol wrote:
> Martin,
> 
>     Are you talking about a physical hummmmmm vs something that others 
> are hearing on your signal?  If so, changing the caps will not help, A 
> physical hum or buzzing sound is usually do to the laminations in one or 
> more of the various transformers and/or chokes vibrating especially 
> under load.  In this case tightening the hardware on the offending 
> transformer or choke MIGHT help the problem.  In most cases the only 
> real fix is to have the transformer rebuilt.  You may also get away with 
> taking it to a local motor rewinding shop and having it "redipped"  in 
> lacquer.  Or.....you just put up with the annoying buzz until it gets 
> bad enough to make you do one of the above mentioned procedures. 
> 
>   73
> Tony - W9JXN
> 
There are no iron cored components in the 32S transmitters. So it has to
come from the 516F-2 power supply, either audible or as modulation of
the RF output by power supply ripple.

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer

______________________________________________________________
Collins mailing list
Home: http://mailman.qth.net/mailman/listinfo/collins
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Collins at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html