the astron will still hum because
 the transformer's primary is still active   turn it off let it sit and turn it back on   the grounding place is on the bottom rear of the supply not the back but under it next to one of the feet The only thing that can kill the transformer itself is either the line fuse next to the line word in back, or the circuit breaker, part of the front panel switch
also dn't forget that rf can make most modern radios go inane as well, as most are software switched rathr han a physical power switch.
On Feb 8, 2011, at 10:08 PM, tom behler wrote:

>  Mike.
> 
> I just checked my Astron RS35 supply, and there is no grounding bolt as you 
> suggest.  On the very left-hand back portion of the supply, there are the DC 
> power connections at the top, followed by a fuse, and finally, there's the 
> AC power cord connection.
> 
> When things shut down as I key up, it still sounds to me like the power 
> supply is on--in other words, the hum doesn't go away, as I think it would, 
> if it had shut down completely.  This is why I'm thinking the floating 
> ground might have something to do with the rig runner.
> 
> But again, I can't be sure.
> 
> So, keep on speculating, and before too long, I'll have dozens of things to 
> try.
> 
> 73 from Tom Behler:  KB8TYJ
> 
> 
> ----- Original Message ----- 
> From: "Mike Duke, K5XU" <[log in to unmask]>
> Tco: "Tom Behler" <[log in to unmask]>
> Sent: Tuesday, February 08, 2011 8:56 PM
> Subject: Gary's Post Made Me Think Again
> 
> 
> Some, but not all, of the PS35 Power supplies, have a grounding bolt
> on the back panel near where the AC line cord comes out of the
> cabinet.
> 
> If yours has that grounding bolt, run a wire from it over to your
> station ground, or attach a counterpoise to it.
> 
> One more thing about a counterpoise, especially one which is indoors.
> 
> You don't have to use copper strap or brade for the counterpoise
> wires.
> 
> Zip cord type speaker wire from Wall-Mart will work just fine in that
> application. You can use both conductors, or just one, or even pull it
> apart and have two completely separate counterpoises.
> 
> It's that mad scientist thing again.
> 
> 
> 
> 
> 
> Mike Duke, K5XU
> American Council of Blind Radio Amateurs