[Elecraft] KPA1500 Power Supply noise

[N4ZR]

Not heard here, although my KPA-1500 gets fairly heavy use.  Power 
supply is on the floor, which no doubt helps with noise.

73, Pete N4ZR
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On 3/27/2021 11:06 AM, David Needham wrote:
> My KPA1500 Power Supply is making a noise that has gotten progressively
> louder over time when I transmit. It sounds like a hissing (but it is not
> arcing) when I transmit. The noise is modulated by SSB speech or CW or
> digital modes keying, louder at higher power levels now during the CQWW WPX
> Phone contest.
>
> I am pretty sure it is not RF getting into the Power Supply. I have
> followed K9YC practices of bonding the K3, KPA1500 Power Supply and RF
> decks to the ground bus. All cables going into and between are wound on
> snap on or toroid ferrites.
>
> Has anyone else run across this? I plan to open up the power supply and
> check for loose parts and do some more testing after the contest.
>