[Elecraft] KPA500 Noise While Off

[Fred Jensen]

Perhaps this is because none of us actually inspect our electricity 
before buying it?  I don't inspect the gasoline I buy either, and by the 
time it's in the tank in my truck, I've already bought it. [:-)

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 6/27/2018 1:00 PM, Chris R. NW6V wrote:
> I may be wrong, but that may not be what Dick, WM6G, is referring to.
>
> I've had a KPA500 for quite some time, so I have an idea of what
> constitutes "normal."
>
> In the last few months I've noticed that every morning, between roughly
> 9-10 AM, I hear brief 1-5 second pulsations of easily audible hum emanating
> from the KPA500. The pulsing events last perhaps 30 seconds to a minute,
> and may happen more than once.
>
> Yes, this ceases if the power cord is out or the power switch on the rear
> is OFF. But again, it is brief-lived when it occurs, and it's new.
>
> To me, guessing, it sounds like something connected to the main AC feed is
> coming up out of phase, then finally syncing, after which the hum stops.
>
> A neighbor's solar array? I have no idea as of this point.
>
> 73 Chris NW6V
>