RFI
[Top] [All Lists]

Re: [RFI] router RFI

To: rfi@contesting.com
Subject: Re: [RFI] router RFI
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Mon, 04 Mar 2013 09:57:29 -0800
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
On 3/3/2013 9:51 PM, N1BUG wrote:
This particular carrier needs to go away, if possible. It is at the home of our county EC and ARES coordinator. Our ARES repeater happens to be on 147.210.

Hi Paul,

Several thoughts.

First, Dale noted a similar carrier at 147.39, and we know that Ethernet birdie frequencies are driven by the fact that each Ethernet switch is free-running with its own crystal controlled oscillator. SO -- changing out the physical switch (which may be part of a wireless router) could move the birdie off of 147.21 MHz.

Second, a case could clearly be made that this device, wherever it is located, is interfering with licensed radio communications, and Part 15 could be invoked to persuade its owner that it must be fixed.

Third, if the device can be located, my guess is that it MIGHT be sufficiently suppressed by a 4 - 6 or so 1-inch long #43 cores on each cable connected to it, and to the other end of Ethernet cables connected to it. That won't help, of course, with stuff radiated by the box itself.

When thinking about problems like this, it helps to think about HOW MUCH suppression is needed. Those cores aren't going to get you 40 dB, but they might get you 10-20 dB, and that might be enough.

I'm assuming you've already determined that the bad box is not his own (by killing power to it).

You might be able to fox hunt the source with a 2M talkie. When participating in our annual radio club fox hunts (the North Shore Radio Club in suburban Chicago), I learned that I could make my talkie's rubber duck directional by holding it close to my body to block it from one direction. And when I got close enough, I added an attenuator by removing the duck.

73, Jim K9YC
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi

<Prev in Thread] Current Thread [Next in Thread>