"Bob" wrote in message
. com...
The J-pole crowd seems to tout fantastic claims about this antenna and I
have never been impressed. Many people have tested the J-pole against
other easy to make antennas and the end fed half wave J-pole usually
does not stand up to even it’s brother, the center fed half wave dipole.
I assume the decrease in performance is due to mistakes in assembling
and tuning the matching section. Here is a link to a group that tested
some J-poles against other antennas in the CA desert and the J-pole lost
to even simple 1/4 wave ground plane types.
http://www.geocities.com/SiliconVall...5/anttest.html

snip

A quick look at the numbers doesn't make the j-pole look so all-fired bad.
"Losing" by 1 dB or so isn't a serious loss. Ham radio isn't exactly the
Kentucky Derby.

I don't know what "fantastic claims" you've heard, but my affinity for the
j-pole comes from its simplicity and durability. It's a halfwave vertical
that requires no ground plane and can often be matched to 1:1 at the sweet
spot. Mounting is a dream -- it even works if you drop the low end into a
plumbing vent pipe. (How would I know that? ;-)

I have never built a center-fed halfwave, but we use a bunch of them in the
Navy -- call them "stovepipes" because of the way the fiberglass housings
look -- and they work very, very well. The elements are large metal
cylinders, tending to make them quite broadband. I do not know how they're
fed ... balun or what.

John , KD6VKW