Re: [drakelist] L-4PS hum

[K9SQG]

[EMAIL PROTECTED] made an utterance to the drakelist gang ----------------------------------------------------------------------

Joe,

I've rebuilt an number of L4B supplies and have found in several cases of 
hum, it was caused by a mechanical "resonence" if you will between the outer case 
and the transformer core.  Reshaping the case or putting stiff foam rubber 
between the case and core can help.  While I've not done this on an L4PS, I have 
cured hum on some other transformers by flowing flowable RTV onto the 
windings, from above, let it cure, then from below.  Sometimes it works, sometimes 
not, but only if a winding is loose.  The flowable RTV is sold as windshield 
sealant for cars and is flowable where standard RTV is not.  If a lamination is 
loose, then tightening the bolts might help.

73,

Evan


**************
It's Tax Time! Get tips, forms and advice on AOL Money & 
Finance.
      (http://money.aol.com/tax?NCID=aolcmp00300000002850)

---------------------------------------------------------------------- Submissions: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------