From: shaun.at.pukekohe@gmail.com   
      
   Once upon a time on usenet Trevor wrote:   
   > On 19/03/2018 1:05 PM, ~misfit~ wrote:   
   >> Once upon a time on usenet Trevor wrote:   
   >>> On 18/03/2018 11:08 AM, ~misfit~ wrote:   
   >>>> Once upon a time on usenet Trevor wrote:   
   >>>>> On 17/03/2018 1:22 AM, audioguymn@gmail.com wrote:   
   >>>>>> On Friday, July 27, 2001 at 2:34:43 PM UTC-5, MitchSF wrote:   
   >>>>>>> Hi, I'm almost finished restoring a KLH Model 21.  I replaced   
   >>>>>>> three transistors on the RF board and it now works!   
   >>>>>>>   
   >>>>>>> The only problem left is a hum from the audio board.  I   
   >>>>>>> disconnected it from the input to the board so I'm sure it's not   
   >>>>>>> coming from anywhere else.  I replaced the filter capacitor and   
   >>>>>>> all electrolytics on the audio board and it's a little quieter,   
   >>>>>>> but still there.  The level of the hum doesn't change with the   
   >>>>>>> volume control.   
   >>>>>>>   
   >>>>>>> Any hints would be appreciated!   
   >>>>>>>   
   >>>>>>> Thanks, Mitch   
   >>>>>>   
   >>>>>> Hi Mitch. The power supply filters, either of the black color   
   >>>>>> are/were a common failure item. They should be replaced. However,   
   >>>>>> note that the positive terminal was marked with the stripe as we   
   >>>>>> would now associate with the negative terminal. It is also   
   >>>>>> important that you do not increase the value of these capacitors   
   >>>>>> as the power supply can't handle the extra in-rush and   
   >>>>>> operational paramete5rs. Mark - Former National Service Manager,   
   >>>>>> KLH Cambridge.   
   >>>>>   
   >>>>> Wonder whether he even still has it 17 years later? :-)   
   >>>>>   
   >>>>   
   >>>> Probably not - at least not with the issue still (however somebody   
   >>>> might...) It's good to have a knowledgeable person posting here so   
   >>>> let's not   
   >>>> be too harsh...   
   >>>   
   >>> True, might help someone else, and I wouldn't want to discourage   
   >>> that. I'm just amazed at how many people answer 20 year old posts   
   >>>   because they don't even realise it. :-)   
   >>   
   >> As you likely know it's usually because these days most people don't   
   >> actually use usenet - they use parasitic web forums that don't   
   >> delete old posts in an effort to appear to have lots of content.   
   >>   
   >   
   > Yes I know, and many are from Google Groups, but I would have thought   
   > the date was still shown somewhere? But then I've never used it   
   > myself.   
      
   Nor have I - at least not for posting. Once or twice I've tried to search   
   for an old post. The bastards took over Deja news archives and butchered   
   them!   
   --   
   Shaun.   
      
   "Humans will have advanced a long, long way when religious belief has a cozy   
   little classification in the DSM*."   
   David Melville (in r.a.s.f1)   
   (*Diagnostic and Statistical Manual of Mental Disorders)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)