[Elecraft] K2 and Feedback

[Larry]

I have a Heil Clearspeech speaker and it specifically recommends a 
separate power supply for the speaker, do not run off the same supply as 
the rig.
I didn't see the reason for that, so I hooked the speaker up to the same 
supply I used for the K2. It sounded pretty good a low volume, but when 
I cranked up the K2, I heard feedback. Figured it was time to listen to 
the manual and hooked up a separate 12vdc supply to the speaker, and 
sure enough, plenty of volume and no feedback.
I didn't notice an issue with grounding.
I realize this doesn't specifically answer your question, but I think 
you're on the right track using a separate supply.

73
Larry
WA2DGD



David Fleming wrote:
> I have a significant feedback problem with my K2/KPA100.  When 
> transmitting there feedback (sounds as clear and as loud as a PA system) 
> through an attached external speaker.  The only partial solution I have 
> found is to use a sea rate power supply for the K2 and NOT connect the 
> power supply to ground. This makes a noticeable reduction in the 
> feedback.    However, as soon as I attach the power supply to ground the 
> feedback returns.   It seems there should be a solution other than not 
> connecting the power supply to ground. Suggestions and help will be 
> gratefully appreciated.
> 
> Dave Fleming KB3HCL
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