Every one of those units has that same problem.


Sent from my iPhone

On Aug 24, 2010, at 10:46 PM, Steve Dresser <[log in to unmask]> wrote:

> Tom,
> 
> That hum is probably caused by vibration of the metal case.  You may be able 
> to fix it by pushing on the cover, or by removing the cover and putting it 
> back on again.  Then again, it may just remain the same.  I wouldn't leave 
> that padding underneath the supply; it's probably blocking air flow around 
> the case, which may cause unwanted heat build-up, which will give you a far 
> worse problem than the mechanical hum you're hearing.  Of course, you could 
> always mount the power supply on the outside of the motor home and drill 
> holes for the wires.  You wouldn't hear the hum, but you might not like the 
> wind and other weather elements coming through the holes.
> 
> Steve
> 
> 
> Steve
> 
> ----- Original Message ----- 
> From: "tom behler" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Tuesday, August 24, 2010 21:42
> Subject: Noisy Astron RS35 power supply
> 
> 
>> Hi, all.
>> 
>> I don't know whether it's because of being jolted around in the move or
>> what, but my trusty metered Astron RS35 power supply seems noisier than it
>> used to be.
>> 
>> It still works fine, but seems to have a louder hum than it used to have.
>> 
>> I have it set up in exactly the same way I did out in Colorado, on the top
>> shelf of a sturdy ham operating desk.  I even put some padding underneath
>> the supply, but it really didn't seem to do much.
>> 
>> I suppose I could take the cover off, and try to feel around to see what
>> might have happened, but I know there are some electrolytic capacitors in
>> there that would not make for a pleasant experience if they were
>> accidentally discharged.
>> 
>> If anyone has had this experience, and has any suggestions, please let me
>> know.
>> 
>> Again, the supply still works fine;  it just lets me know it's around more
>> than it used to.  (smile)
>> 
>> 73 from Tom Behler:  KB8TYJ
>>