[TenTec] Audio Hum on Omni-VII

Dudley Hurry jhurry at austin.rr.com
Wed Sep 17 23:32:00 EDT 2008


Bill,

You have a ground loop to the laptop..  I bet that you will lose the hum 
if you break the ground from the radio to/from the laptop sound card..   
Better isolation from the radio to the sound card.  

You might even try an extra ground from the laptop to station ground,  
but it is most likely a audio loop,  isolation transformers should take 
care of it.. 

73,
Dudley

WA5QPZ



Bill and Cindy wrote:
> I just got my new Omni-VII last week. It seems to be a great radio, the second radio in the
> shack is an Omni-VI+, so I knew what to expect......
>  
> There is a hum on the audio. The Omni-VII is keyed from an old Compaq laptop running
> N1MM software, through an Array Solutions SO2R switch box. The hum COMPLETELY
> disappears when the AC/DC adapter power cord is pulled out of the laptop and the
> computer is on battery power. I don't remember this happening with the Omni VI+....
>  
> Hmmm (no pun intended). Is this the AC/DC adapter going bad? The computer apparently
> takes 18.5 V at 2.7 A based on the listed output of the AC/DC adapter. What if I just
> power the laptop from the 13.8 V MFJ power strip that powers all the other accessories?
> Will this work?
>  
> Thanks, Bill /  KO7AA in Tucson
>
>
>       
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