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Michael Coslo · October 4th 07, 08:59 PM posted to rec.radio.amateur.moderated

wrote:
On Oct 2, 3:20?pm, Michael Coslo wrote:
wrote:
On Sep 28, 9:29?am, Michael Coslo wrote:

Depending on the transmission line impedance and
length, the shack-end Z could be within the matching range
of the Transmatch.
A few years back I did a modeling of an antenna that was 1/4
wavelength
long at I think 40 meters. The SWR of the antenna was
approaching infinite.

???

With reference to what sort of feedline? SWR only has meaning
wrt a particular line impedance.

When I came up with infinite SWR, I didn't spend a whole lot more time
on the antenna. I could probably match it with a super long piece of
coax, and attendant loss, but it is really so much easier to change the
length so it isn't 1/4 wave on any desired frequency I might want, have
the SWR at a manageable level, and use the tuner.

I look at it as one of those things that are easy to avoid.

snippage

I've heard of
some of the drawbacks of window line, such as it's performance when wet.

I did take issue with the test method cited by many, in which
the window
line was dunked in water that included a wetting agent.
My contention is
that the experiment showed the effects on window line with
wetted line.

My experience has been that window line does not wet
in this manner.
When the experimenter has to add a chemical to coat
the line with water,
it is altering the conditions and producing results germane to only
those conditions.

I agree. A spray with the garden hose will adequately simulate a
rainy day, I think.

That is the case. I have heard that some ladder line will get "frosted"
by sandstorms or even have moss grow on them, which could lead to
trouble re wetting, or being somewhat submerged in a wet substance, but
that is kind of extreme. I've got 5 year old window line that still has
the water bead up on the poly.

- 73 de Mike KB3EIA -