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Old December 17th 13, 12:42 PM posted to rec.radio.amateur.antenna
Jerry Stuckle Jerry Stuckle is offline
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First recorded activity by RadioBanter: Oct 2012
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Default Turning a 1/4 wave vertical upside down

On 12/16/2013 10:44 PM, Jeff Liebermann wrote:
On Mon, 16 Dec 2013 11:21:30 -0800, David Harmon
wrote:

On Sun, 15 Dec 2013 23:43:26 -0800 in rec.radio.amateur.antenna,
Jeff Liebermann wrote,
Marginally related RF drivel: One of my friends is avid DX'er. He
has all his media and computer gizmos interconnected via Wi-Fi because
Wi-Fi creates less RFI than ethernet.


Woah, how can that be? Would using shielded cat6 fix it?


I don't know. I don't have much experience with CAT6 STP as most of
my installations use CAT5e UTP cable (including for gigabit). It
might reduce radiation by shielding, or increase it if there's a
ground loop. In any case, the owner was not interested in wiring the
house, station, garage, antenna farm, front gate, home theater, etc
for ethernet. Wi-Fi did the job well enough and did not product RFI.

In retrospect, I probably should have spent more time finding the
exact sources of the HF interference. I did not make a systematic
check of the house, and did not check everything electrical in the
house. I didn't have the time as that would have taken days. Instead,
there was a large drop in RFI observed when the ethernet connected
devices were unplugged, so we went with that.



Actually, if you have the right equipment, you can narrow it down in a
very short time. It seldom takes us more than an hour to find RFI
problems, and most can be done in 10-15 minutes. It never takes us
days, even in large installations.

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