starman wrote:
Harris wrote:

Bill Hansen wrote:
I have 90 feet of NEW 19 strand 1/4" OD all copper antenna wire listed on eBay.

Click here to see a picture of it:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3083121559

Thanks, I got a good chuckle out of that!

Art N2AH

It looks like common electrical grounding wire, which means it's not
made for being under tension as an antenna wire. It was probably left
over from a home wiring project.

Well it's good heavy wire, although plain copper like this will
stretch under tension. Definitely overkill for an SWL. But what was
particularly amusing was the claim that the somewhat larger surface
area would capture more signal. Wrong!

Capture area is one of the more misunderstood things among hams/swls.

Did you know that an 80 meter dipole (approx 135 feet long) made of
thin wire has a capture area of over 8,000 square feet at its resonant
frequency? It's true!

Art N2AH

In article ,
(Art Harris) wrote:

starman wrote:
Harris wrote:

Bill Hansen wrote:
I have 90 feet of NEW 19 strand 1/4" OD all copper antenna wire
listed on eBay.

Click here to see a picture of it:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3083121559

Thanks, I got a good chuckle out of that!

Art N2AH

It looks like common electrical grounding wire, which means it's
not made for being under tension as an antenna wire. It was
probably left over from a home wiring project.

Well it's good heavy wire, although plain copper like this will
stretch under tension. Definitely overkill for an SWL. But what was
particularly amusing was the claim that the somewhat larger surface
area would capture more signal. Wrong!

Capture area is one of the more misunderstood things among hams/swls.

Did you know that an 80 meter dipole (approx 135 feet long) made of
thin wire has a capture area of over 8,000 square feet at its
resonant frequency? It's true!

How long the dipole should be depends on the frequency or frequencies
one wants to receive well. Larger dipoles are for lower frequencies.
Generally it is best to consider the lowest frequency you want to listen
to and use that resonant length. The much longer than needed dipole at
the higher frequencies will work well except at certain specific
frequencies, which will be the even multiples of the chosen dipole
length.

The consequence of resonant antennas means that at least two dipoles
need to be made. The second should be an odd harmonic length to the
first so all bands will be covered. Actually I would advocate that
people make two different types of antennas like a dipole and a loop.
Times and conditions will dictate which will work better.

Larger diameter wires will have broader resonant characteristics but for
receiving will have no impact. The diameter and other metallurgical
aspects of the wire should be considered for the strength and longevity
of the installation.

--
Telamon
Ventura, California

Well it's good heavy wire, although plain copper like this will stretch
under tension.

If that's 19/16 Copperweld(? -- hard drawn copper), it won't sag under normal
conditions. It's supports may, though. G That stuff is heavy.

Bill, K5BY