[Amps] AL-80B has developed a loud transformer hum

[Mansfield Aubrey]

Although no bolts or screws were obviously loose apparently there were enough that were marginally tightened to cause the transformer hum.  I tightened everything around the transformer (including over tightening and breaking a bolt that mounts transformer to chassis) and the hum is gone.

Thanks to all that replied.  

73,
- Aubrey N3BM

On Sep 30, 2012, at 9:00 PM, Ron Youvan <ka4inm at gmail.com> wrote:

>  Hi  Aubrey N3BM:
> 
> <<
> My 5 week old AL-80B has developed a loud transformer hum when keyed. It's very noticeable (and annoying), even with headphones on.  Is this normal?
> >>
> 
>  It is not normal, but it is most likely a minor thing.
> Tighten any and all mounting bolts on, to or near the transformer.
> The magnetic field of the transformer can go out at least two inches, so any ferrous thing that is loose can vibrate and cause audible noise.  GL es 73
> -- 
>   73 Ron KA4INM - All E-mail sent to this address shall linger in the Google cloud forever!
>