Roy Lewallen wrote:
Mike Coslo wrote:


So is the lesson that Ladder line sucks, or is it that we
shouldn't wash our ladder line with soap and water? 8^)


Although I discovered it long ago, I keep getting surprised at how many
people require a binary answer to any question -- is it good or bad,
sucks or doesn't suck, good or evil. Sure makes it easy for our would-be
politicians and their 15 second sound bite solutions to complex issues.

Hi Roy. I must have used the incorrect wording here. I'm pretty well
convinced that PE coated ladder line doesn't suck. Just one of those
email things I guess... 8^)


Hopefully at least some readers will consider what Owen said, that the
knowledge we've gained by this can hopefully help in the intelligent use
of the line. Those needing a binary answer should look elsewhere; there
are plenty of gurus who are more than happy to categorically state
positive but simple answers to just about any question. I use a coin,
myself, but each to his own.

I ask the questions that I do to find out what might be going on. I've
learned a few things here. one is that if you coat PE with some
substances, it will alter it's properties.

Another is that there is a measurable difference in loss when a PE line
is coated with a wetting agent, which is needed to evenly (read wet)
coat PE with water. Some portion of this could be applicable to
non-wetted PE coated line.


Wes' and my measurements, and Danny's observations, can't be directly
applied to other situations. What they're meant to, and do, illustrate,
is that significant loss *can* occur under some circumstances, and
people who assume that twinlead or window line loss will always be low
can be very much mistaken.

However, some *are* applying them to other circumstances.


Has anyone run tests on what "real" (open) ladder line does when
you spray it with wetting agent and water?


I don't think any result would be very meaningful, except to show,
again, that significant loss could occur under some conditions (which
I'm confident is the case).

Agreed.

Those lines are often run with a very high
SWR. The effect of conductivity and/or loss across the insulators would
depend very heavily on the position and size of the standing waves. For
example, if the SWR is high and the insulators happen to be at or near
the voltage peaks, even a small amount of loss would have a major
impact. But on a slightly different frequency, the antenna's impedance
will change and the standing wave will move.

Good point

If most insulators are near
voltage minima, you wouldn't likely notice even quite a bit of loss.
This effect would be most pronounced at higher frequencies where the
spacing between insulators might become a sizable fraction of a
wavelength, and not so pronounced at lower frequencies or with more
insulators. But the magnitude of the SWR would still make a major
difference.

I would assume then that the big difference is the continuous coating of
the PE then?

Thanks for the feedback, Roy, I'm here more to learn than to argue.
(perhaps Quixotic?)

-73 de Mike KB3EIA -