"Mark Rand" wrote in message
...
On Sat, 26 Sep 2009 14:44:31 -0400, "Ed Huntress"

wrote:



What Justme said has been common knowledge to ham radio operators for more
than half a century. SWR doesn't matter much with ladder line, partly
because of its low loss and partly because most of the antennas it's
usually
feeding are no great shakes themselves, and radiation from the
transmission
line is tolerable. I switched from a balun-type coax-fed dipole to a
ladder-line-fed folded dipole once, both of them in the exact same
position,
and I got much better reports on the one fed with (300 ohm) ladder line.
And
I'm sure that the SWR on that line was out of whack.


But a folded dipole is nominally 300 ohm (292 ish). Am I misunderstanding
the
magnitude of "not mattering much"? I had the image of people sticking a
quarter wave stick on the end of a ladder line and calling it good...

They might get away with it, too. g

At the HF bands most of us are familiar with, it's unusual to see simple
antennas that are high enough to avoid radiation distortion and impedance
distortion as a result of their proximity to the ground. If you have a VSWR
meter and a willingness to tune the whole affair, you can get good matches
all around. If not, you'd might as well feed the antenna with a low-loss
ladder line and be done with it. You'll get more radiative power out, in
most cases, even if some of it is coming off of the feedline.

--
Ed Huntress



Mark Rand (Not a wireless person, even though I'm now doing wireless
networking at work)
RTFM