Any real fans of ladderline?
 

Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ

http://www.qsl.net/w5dxp/notuner.htm


"zeno" wrote in message ...
Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ

I don't have a loop like yours, but I do feed a couple of antennas with
commercial 450-ohm ladder line. No problems bringing it into the house. In
fact, it cleaned up a few TVI problems I had when feeding an antenna with
coax.

73,
Mike KI6P{R
El Rancho R.F., CA

"zeno" wrote
Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ

"zeno" wrote in message ...
Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ


I use 450 ohm ladder line on two seperate antennas here. One is a full
sized 40 meter loop, in right triangle configuration, vertical. I run the
line straight into the shack and into a EF Johnson Matchbox. Works all
bands 40 thr 10 just fine. I run 600 watts into it, and no problems. No
TVI, No computer faults, no telephone problems.

On the other antenna I have a 140 CF doublet with 450 Ladder Line feed.
This into a Heathkit SA-2040 tuner. Same same as above.

The reason I am able to run the LL into the shack is that I have a large out
building that I have the shack in. Run it right through, not a problem.

Just keep the line away from conductive objects and I run it up to my
ceiling then out.

Dan/W4NTI

With general purpose, multi-band antennas such as yours, taking one band
with another, the higher the feedline impedance the less the loss in the
feedline.

This is because feedline attenuation in dB is directly proportional to R/Zo
where R is the resistance of the feedline conductors and Zo is the line
impedance. This simple relationship applies from 50-ohm coax (or lower) up
to 600-ohm (or more) wide-spaced open-wire line.

Ordinary 50-ohm coax is fine ONLY when the input impedance of the antenna is
itself approximately 50 ohms purely resistive and the line length is not
very long. But with multi-band antennas Zin is most unlikely to be anywhere
near 50-ohms on any band. It is more likely, taking one band with another,
to be several hundred ohms or even 1000 ohms with a high reactance
component.

Assuming the conductor resistance to be of the same order for both coax and
balanced-pair lines of the same length, line loss will be appreciably less
for the higher impedance lines. In fact, for the physical sizes usually
involved, spaced balanced wires have a lower conductor resistance than
ordinary coax and this swings the use of spaced lines further in their
favour.

Even a 300-ohm twin line with substantial conductors, not the flimsy old TV
downlead type, will effect an improvement over the usual sort of coax.
450-ohm ladder line is most popular because of cheapness and relative ease
of installation. But for perfectionists, on very long lines, a 5" or 6"
spaced 600-ohm work-of-art cannot be bettered.

With low-loss, high-Zo lines SWR on the line can usually be forgotten about.
But a high SWR can make severe demands on the tuner however.

Transmission line Zo, of course, is unrelated to antenna efficiency which
with a high antenna is nearly always good enough to be considered 100%.
----
Reg, G4FGQ

I don't have a loop but I have used 600 ohm open wire line for years and
love it!

It does require good tuner or, in Cecil's designs, controlled lengths of
line, for a good match. I transition from ladder line to coax using a
current balun and bring the coax into the shack. This is about a 10 foot
run of coax. I run a KW when required and no problems in wind, rain,
snow or ice.

Deacon Dave, W1MCE
+ + +

zeno wrote:

Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

"Peter" == Uncle Peter Uncle writes:

Peter http://www.qsl.net/w5dxp/notuner.htm

That is the cleverest thing I've seen today. Wow. Very nifty.

My only concern when constructing something like that is how to store
the longer lengths (eight and sixteen) of ladder line -- can they be
coiled up? If so, it's less unwieldy and can scale even higher.

Of course, those hams who know binary arithmetic will luck out here.

Jack.
- --
Jack Twilley
jmt at twilley dot org
http colon slash slash www dot twilley dot org slash tilde jmt slash
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (FreeBSD)

iD8DBQFAjFdMGPFSfAB/ezgRArzcAJ42I07VGe2bpeKCs9sdN9V2jNfpDgCdGLPL
Yul13ErgNKsQLK1xE4fxco8=
=KS37
-----END PGP SIGNATURE-----

"Dan/W4NTI" w4nti@get rid of this mindspring.com wrote in message
link.net...

"zeno" wrote in message
...
Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ


I use 450 ohm ladder line on two seperate antennas here. One is a full
sized 40 meter loop, in right triangle configuration, vertical. I run
the
line straight into the shack and into a EF Johnson Matchbox. Works all
bands 40 thr 10 just fine. I run 600 watts into it, and no problems. No
TVI, No computer faults, no telephone problems.

On the other antenna I have a 140 CF doublet with 450 Ladder Line feed.
This into a Heathkit SA-2040 tuner. Same same as above.

The reason I am able to run the LL into the shack is that I have a large
out
building that I have the shack in. Run it right through, not a problem.

Just keep the line away from conductive objects and I run it up to my
ceiling then out.

Dan/W4NTI

slightly off topic....

Hi Dan,

What kind of lightning protection do you employ for straight ladderline?
What are the options (besides tossing it out the window) - if you aren't
using any? I don't run any feeds through my windows, so I wondered what
options that left for ladderline, etc.

Thanks

Jack
Virginia Beach

On Sun, 25 Apr 2004 21:37:53 -0400, "Jack Painter"
wrote:


"Dan/W4NTI" w4nti@get rid of this mindspring.com wrote in message
hlink.net...

"zeno" wrote in message
...
Seems like everyone I talk to about using ladder line to my
proposed 540' horizontal skywire loop does a double take when
I say I want to use ladder line into the shack. I was curious
if there are any fans of ladderline feed systems who can
relate positive experiences, or am I about to really court
disaster here.

The ARRL antenna book says that coax to this type of antenna
is not as "multiband" friendly as was once fantasized....they
recommend ladder line.

Anyone actually have such a loop? What is your experience?


Bill, K6TAJ


I use 450 ohm ladder line on two seperate antennas here. One is a full
sized 40 meter loop, in right triangle configuration, vertical. I run
the
line straight into the shack and into a EF Johnson Matchbox. Works all
bands 40 thr 10 just fine. I run 600 watts into it, and no problems. No
TVI, No computer faults, no telephone problems.

On the other antenna I have a 140 CF doublet with 450 Ladder Line feed.
This into a Heathkit SA-2040 tuner. Same same as above.

The reason I am able to run the LL into the shack is that I have a large
out
building that I have the shack in. Run it right through, not a problem.

Just keep the line away from conductive objects and I run it up to my
ceiling then out.

Dan/W4NTI

slightly off topic....

Hi Dan,

What kind of lightning protection do you employ for straight ladderline?
What are the options (besides tossing it out the window) - if you aren't
using any? I don't run any feeds through my windows, so I wondered what
options that left for ladderline, etc.

I've found the easiest thing is to insert banana jacks/plugs in the
ladderline just outside the window. When the clouds come, I simply
unplug.

The Wireman sells a balanced-line lightning arrester built around a
couple of spark plugs, but I'm not sure how well it works.

Bob
k5qwg


Thanks

Jack
Virginia Beach

Reg Edwards wrote:

Even a 300-ohm twin line with substantial conductors, not the flimsy old TV
downlead type, will effect an improvement over the usual sort of coax.
450-ohm ladder line is most popular because of cheapness and relative ease
of installation. But for perfectionists, on very long lines, a 5" or 6"
spaced 600-ohm work-of-art cannot be bettered.

any reason that silicon sealant would not be as good as anything else when
fixing (gluing) the wires to the slotted holes of the spacers in a homebrew
ladder line? Any reason why this same substance would not be appropriate to
seal up the ceramic tubes where such lines go through a wall?

this stuff is tough, weather resistant, sticks, and stays flexible.

Bill, K6TAJ