On Sat, 23 Sep 2006 14:32:19 GMT, Cecil Moore
wrote:


Wow, from 0.2 dB to 0.4 dB. :-) Would the following
work for measuring the wet/dry losses of 1/2 wavelength
of ladder-line shorted at one end and an MFJ-259B on the
other end? Measure the resonant purely resistive impedance
at the open end. Wet the ladder-line and repeat the
procedure. Calculate the losses.

If the line were lossless, zero ohms would be read.
The deviation away from zero ohms yields the magnitude
of the loss in the line at the 1/2 wavelength resonant
frequency. That's about 8.8 MHz for 50 ft. of ladder-line.

You are assuming something that I am not. That is the measurements
were accurate. Measuring anything to a fraction of a dB is most
difficult - even with the best of equipment and mine was not.

Danny, K6MHE

John, N9JG wrote:
The author used a wetting agent.

"Cecil Moore" wrote in message
m...

John, N9JG wrote:

An excellent article. It appears to indicate that at 7 MHz a feed line
made from 100' of Wireman 554 window line would have a loss of about 2 db
when the line is wet. When the line is dry, the loss is insignificant.

I've often wondered how someone "wets" a vertical feedline
without using soap.

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

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

- 73 de Mike KB3EIA -

On Fri, 22 Sep 2006 20:24:59 -0700, Danny Richardson
wrote:

On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore
wrote:

Danny Richardson wrote:
Just drop by my qth anytime between November and May.

How do you keep the water on the feedline? Mine
always beads up and falls to the ground.

Here's a photo of a piece of Danny's line (Wireman 552), after it set
around in the Arizona 5% humidity for a while It was still green when
I got it.

http://www.k6mhe.com/n7ws/MossyLine.jpg

What do you suppose the dielectic properties are when that stuff
totally bridges the line and is wet?



I don't do anything. Ever heard of Oregon mist?

When I first moved up here on the northern California coast I put up a
doublet feeding it with window line. The next spring when I dropped
the antenna for some maintenance I found moss growing on the feed
line.Need I say it was replaced with something better?

Wes Stewart wrote:
Here's a photo of a piece of Danny's line (Wireman 552), after it set
around in the Arizona 5% humidity for a while It was still green when
I got it.

http://www.k6mhe.com/n7ws/MossyLine.jpg

That's pretty amazing. East Texas is relatively damp
and green but I've never had moss growing on my ladder-
line. Here, the rain comes and goes and doesn't last very
long.

What do you suppose the dielectic properties are when that stuff
totally bridges the line and is wet?

Sounds like a useful project for someone. The only thing on
my ladder-line at the moment is a green six-inch long lizard
looking at me through the window pane.
--
73, Cecil http://www.w5dxp.com

On Sat, 23 Sep 2006 15:23:07 -0400, Mike Coslo
wrote:

John, N9JG wrote:
The author used a wetting agent.

"Cecil Moore" wrote in message
m...

John, N9JG wrote:

An excellent article. It appears to indicate that at 7 MHz a feed line
made from 100' of Wireman 554 window line would have a loss of about 2 db
when the line is wet. When the line is dry, the loss is insignificant.

I've often wondered how someone "wets" a vertical feedline
without using soap.

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

Some suggest coating the ladder line with various forms of waxes, eg
silicon car polish for various reasons, including minimising the
change to the line characteristics with precipitation.

I don't know if there is reliable evidence as to the efficacy of these
measures, and what compounds are to be preferred. I see it discussed
on eham, but that doesn't necessarily mean it is bunk!

I don't know that it is fair to say that "Ladder line sucks", but it
is well known that it is adversely affected by moisture. Ladder line
is not so good wet or dry as to disregard its losses in all situations
(ie in general).

Like everything, it has its limitations, and with knowledge we can use
it effectively within those limitations.

Owen
--

Cecil Moore wrote:
Wes Stewart wrote:

Here's a photo of a piece of Danny's line (Wireman 552), after it set
around in the Arizona 5% humidity for a while It was still green when
I got it.

http://www.k6mhe.com/n7ws/MossyLine.jpg


That's pretty amazing. East Texas is relatively damp
and green but I've never had moss growing on my ladder-
line. Here, the rain comes and goes and doesn't last very
long.

What do you suppose the dielectic properties are when that stuff
totally bridges the line and is wet?


Sounds like a useful project for someone. The only thing on
my ladder-line at the moment is a green six-inch long lizard
looking at me through the window pane.

You sure that ain't just a reflection?
73,
Tom Donaly, KA6RUH

Wes Stewart wrote:
On Fri, 22 Sep 2006 20:24:59 -0700, Danny Richardson
wrote:


On Sat, 23 Sep 2006 02:48:16 GMT, Cecil Moore
wrote:


Danny Richardson wrote:

Just drop by my qth anytime between November and May.

How do you keep the water on the feedline? Mine
always beads up and falls to the ground.


Here's a photo of a piece of Danny's line (Wireman 552), after it set
around in the Arizona 5% humidity for a while It was still green when
I got it.

http://www.k6mhe.com/n7ws/MossyLine.jpg

What do you suppose the dielectic properties are when that stuff
totally bridges the line and is wet?

Seems as if some of us are taking special circumstances and applying
them to all cases. I have the same type of line, and after several
years, it's still glossy, and the water beads up on it.

So should I quit using it because he has problems, or should he keep
using it because I don't? ;^)

- 73 de mike KB3EIA -

Tom Donaly wrote:
You sure that ain't just a reflection?

:-0 Nope, it's one of these critters called an Anole.
Locals call them chameleons because they can change
their colors from green to brown.

http://www.kingsnake.com/hudspeth/AnoleClose1.jpg
--
73, Cecil http://www.w5dxp.com

Owen Duffy wrote:
On Sat, 23 Sep 2006 15:23:07 -0400, Mike Coslo
wrote:


John, N9JG wrote:

The author used a wetting agent.

"Cecil Moore" wrote in message
.com...


John, N9JG wrote:


An excellent article. It appears to indicate that at 7 MHz a feed line
made from 100' of Wireman 554 window line would have a loss of about 2 db
when the line is wet. When the line is dry, the loss is insignificant.

I've often wondered how someone "wets" a vertical feedline
without using soap.

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


Some suggest coating the ladder line with various forms of waxes, eg
silicon car polish for various reasons, including minimising the
change to the line characteristics with precipitation.

Hi Owen.

I doubt that those would help much, as PE has some pretty impressive
characteristics. I suspect that waxes and such will just degrade
performance.

And I can just imagine the look my XYL would give me if I told her I
was going to go wax my line! ;^)



I don't know if there is reliable evidence as to the efficacy of these
measures, and what compounds are to be preferred. I see it discussed
on eham, but that doesn't necessarily mean it is bunk!

I don't know that it is fair to say that "Ladder line sucks", but it
is well known that it is adversely affected by moisture. Ladder line
is not so good wet or dry as to disregard its losses in all situations
(ie in general).

I wonder what the exact mechanism is? PE has some decent water
absorption characteristics, 24 hour tests show almost no absorption for
low density, and none for the high density and up versions.


Like everything, it has its limitations, and with knowledge we can use
it effectively within those limitations.

I daresay you are right.

- 73 de Mike KB3EIA -

Cecil Moore wrote:
Tom Donaly wrote:

You sure that ain't just a reflection?


:-0 Nope, it's one of these critters called an Anole.
Locals call them chameleons because they can change
their colors from green to brown.

Cute little duffer!

- 73 de Mike KB3EIA -