[Elecraft] RF noise on 80M with KPA500 plugged into AC outlet

[Don Wilhelm]

John,

Is that ground rod connected with heavy copper wire (#6 or better #4) to 
the Utility Entry ground rod?  If not, that may be the cause.
Even if it is not the cause of that behavior, it is a safety issue for 
you and your family and is a requirement according to the National 
Electrical Code.  The only exception is if the ground rods are more than 
100 feet apart.

A power cord - connected only to the wall receptacle should not cause 
any noise.
Try the same with another power cord - if the same thing happens, 
examine your house wiring.  OTOH, if the other power cord does not 
produce the noise, you may conclude that the original power cord has 
some sort of leakage problem.

73,
Don W3FPR

On 10/4/2016 11:18 PM, John Freed wrote:
> Here is an interesting situation.  On 80 meters (3.980 MHZ) the background noise goes from S7 to S9+20 when I plug the KPA500 into the AC outlet.  I have not turned on the Amplifier, just plugged it into the AC outlet.  I disconnect the power cord from the amplifier at the amplifier and the noise remains.  I unplug the power cord and the background noise drops back to S7.  This only happens on 80 meters.  I have an idea the outlet may have a grounding problem.  I will test it tomorrow.  Any ideas??
>
> I have a ground bar that all of the radios are attached to.  Single ground wire to an 8 ft ground rod just outside the shack. Hmmmmm!  (me scratching my head)
>
>