No, it's not the fan, it's the oscillator I'm hearing, but I don't know
what components are doing the vibrating. The fan fires up occasionally,
but that noise is entirely different.

Thanks for the response.
B.




Edward L. Dowdy wrote:
Could it be the internal fan running?

73,
Ed KA9EES


"Bob" wrote in message
.. .

Okay, perhaps I'm being a bit picky, but here's the scoop:

I find a lot of switchers are audibly noisy. That is, they emit a 'hiss'
noise from their circuitry. Some units are barely audible, others are