[CW] Off Topic = Noise - A Very Good Message

[D.J.J. Ring, Jr.]

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1. Some low noise antenna ideas
    Posted by:  oneswler at yahoo.com oneswler
    Date: Tue Apr 17, 2018 9:47 am ((PDT))

Over breakfast this morning I mentioned Beverage antennas to my boss who is
also an Extra Class amateur radio operator, with a EE PHD and master
electrician license, and she suggested I pass on this link.

http://www.w8ji.com/receiving.htm http://www.w8ji.com/receiving.htm

While many hams swear by Beverage antennas including W8JI, there are other
low noise antennas that can be built on a regular suburban lot.



She suggested any SWL who is seriously thinking of a Beverage do a lot of
research and look at T2FD, loop antennas, both small and large, flags, etc.
There are many antennas, each will work very well in some locations and not
so well at others.

The most important first step is to figure out your local RF ambient noise
floor. If it is too high, no antenna will overcome that problem. Much of
the EMI [radio noise] comes from our own homes and reducing that is the
first logical step.



While there are many good pages on the issue, she feels most people will
benefit the most from reading, then rereading W1HIS Common Mode Chokes

http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf
http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf

Another good page is

http://audiosystemsgroup.com/publish.htm
http://audiosystemsgroup.com/publish.htm

He also has lots of good links.



For an idea of how far some dedicated radio nuts can be....

http://www.on4ww.be/emi-rfi.html http://www.on4ww.be/emi-rfi.html





I live in a very rural area, and my biggest non self generated EMI source
was the many electric fences around here. Small electrical arcs were
connected directly to up to thousands of feet of fence wire, AKA antennas.

Fortunately everyone in the area is kin to me and they were willing to work
with me to eliminate the problems.





Dealing with EMI produced by a neighbor can be a nightmare.

The only advice I can offer is to never [and I mean NEVER!] touch anyone
else's electrical equipment.

When it dies 5 years from the day you touch it, they will blame you.



Noel
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