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Re: [RFI] High local noise level...

To: rfi@contesting.com
Subject: Re: [RFI] High local noise level...
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Sun, 15 Mar 2015 00:17:36 -0700
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
On Sat,3/14/2015 5:50 PM, Kenneth G. Gordon wrote:
If this is so (and I am NOT arguing with you about the need for better
bonding) why is it that my noise disappears when I disconnect the

Did you study the tutorial? A fundamental cause of triplen harmonics of the power line (divisible by 3) is leakage current from the power line causing a voltage drop on the "green wire where that equipment is powered, making the chassis "hot" with that power line buzz. Every such chassis "grounded" at a different point is at a different potential. If, for example, your antenna is grounded somewhere else, that determines the AC potential of your radio. The DIFFERENCE in potential between the radio chassis and every other chassis is ADDED to any unbalanced interconnection. Like, for example, between the radio and your computer.

On Sat,3/14/2015 8:08 PM, Mike Martin wrote:
If you haven't made changes in your shack its unlikely the cause is bonding on your equipment. However it is likely to have a rectified power line noise accuring on only the positive half cycle. Can you send me a wave file if your noise, I'd like to hear and analyze it.

One possible (likely?) change is the addition of the unbalanced connection to the computer for analysis of the signal. :)

73, Jim K9YC
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