On Jun 12, 5:43*pm, Owen Duffy wrote:
wrote :

...

Even with a 80/1 mismatch, ladder line has low loss.

30m of Wireman 551 with a load of 5+j0 has VSWR=80 at the load end, VSWR=28 *
at the source end, and the transmission loss is 4.6dB... 65% of the input
power is converted to heat.

Speaks to your meaning of "low loss".

Mythical properties are ascribed to ladder line, some of attributable to
ARRL publications.

Owen

I might have been a bit carried away with the degree of mismatch
and loss, but I still think running the ladder/window line the whole
way to the tuner will still be the best in most cases for "all band"
use.
If the major portion of the feed line will still be ladder line, even
with
the coax lead in, he will still deal with the same line losses for the
majority of the run with such a severe mismatch.
It won't be that bad most of the time.
With the coax and choke addition, even more loss is added to the
system. And if he saw an 80:1 mismatch, just 15 feet of RG-8
should cost you half your power at 14 mhz. That's more loss than 15
extra feet of the ladder line which at 80:1, should be about 1 db loss
or so.
I just find the addition of the coax and choke as totally unnecessary
unless there is no way at all to feed the ladder/window line through
to the shack.
Sure, there are losses with the balun used in most tuners, but I
consider that a price to pay for a multi band antenna.
Myself, I don't use many all band antennas..
Most of my dipoles are single band, and coax fed. :/
Here is one online calculator which seems to match your
numbers fairly close if set for 14 mhz. They include the
551 line as one of the choices.
I notice "generic" 450 line has less loss.. I don't know
what the difference is between generic and 551..
Maybe 551 has more plastic, and less open window..
I notice generic 600 ohm ladder line will show about 2.2 db
loss with an 80:1 mismatch. I'll agree.. Maybe not low loss,
but it's quite usable considering an ugly 80:1 mismatch.


http://www.qsl.net/co8tw/Coax%20Calculator.htm

wrote:

Sure, there are losses with the balun used in most tuners, but I
consider that a price to pay for a multi band antenna.


Chiming in late on this one...


Mythical attributes aside, I believe the real reason that ladder line
has become more popular is:

1. Almost all rigs are All HF band these days.

2. Many people have just one antenna they can put up at any given time.
Whether it is space considerations, maintaining a low profile or
keeping the XYL happy I remember the discussions with my wife when I
wanted to put up the HF vertical. "Why do you need two antennas?" "Are
you going to transmit two signals at the same time?". Twasn't easy, and
a lot of Hams might lose that argument.

So assuming it is a doublet, and I wanted to run 80 to 10 meters, I'd
put up much wire as I could, not mess with coax, just run ladder line to
a window panel, then into the house, into a tuner that can handle
balanced line. And pay attention to the lengths that might make for
trouble in matching.

- 73 de Mike N3LI -

Mike Coslo wrote:
wrote:

Sure, there are losses with the balun used in most tuners, but I
consider that a price to pay for a multi band antenna.


Chiming in late on this one...


Mythical attributes aside, I believe the real reason that ladder line
has become more popular is:

1. Almost all rigs are All HF band these days.

2. Many people have just one antenna they can put up at any given time.
Whether it is space considerations, maintaining a low profile or
keeping the XYL happy I remember the discussions with my wife when I
wanted to put up the HF vertical. "Why do you need two antennas?" "Are
you going to transmit two signals at the same time?". Twasn't easy, and
a lot of Hams might lose that argument.

So assuming it is a doublet, and I wanted to run 80 to 10 meters, I'd
put up much wire as I could, not mess with coax, just run ladder line to
a window panel, then into the house, into a tuner that can handle
balanced line. And pay attention to the lengths that might make for
trouble in matching.


Or, put up as much wire as you can, put an autotuner at the feedpoint,
and run coax back to the shack.

probably a six of one, half dozen of the other, depending on what you
already have, what kind of support structures you have (if you are
putting up an inverted V, then supporting the weight of the tuner isn't
an issue..), etc.

"Jim Lux" wrote in message
...
Mike Coslo wrote:
wrote:

Sure, there are losses with the balun used in most tuners, but I
consider that a price to pay for a multi band antenna.


Chiming in late on this one...


Mythical attributes aside, I believe the real reason that ladder line has
become more popular is:

1. Almost all rigs are All HF band these days.

2. Many people have just one antenna they can put up at any given time.
Whether it is space considerations, maintaining a low profile or keeping
the XYL happy I remember the discussions with my wife when I wanted to
put up the HF vertical. "Why do you need two antennas?" "Are you going to
transmit two signals at the same time?". Twasn't easy, and a lot of Hams
might lose that argument.

So assuming it is a doublet, and I wanted to run 80 to 10 meters, I'd put
up much wire as I could, not mess with coax, just run ladder line to a
window panel, then into the house, into a tuner that can handle balanced
line. And pay attention to the lengths that might make for trouble in
matching.


Or, put up as much wire as you can, put an autotuner at the feedpoint, and
run coax back to the shack.

probably a six of one, half dozen of the other, depending on what you
already have, what kind of support structures you have (if you are putting
up an inverted V, then supporting the weight of the tuner isn't an
issue..), etc.

for most people the feedline won't be that long so just put up the inverted
v, wind a coax choke at the feed point (or not) and just run it back to the
shack and use the tuner in the rig.

Jim Lux wrote:
Mike Coslo wrote:
wrote:

Sure, there are losses with the balun used in most tuners, but I
consider that a price to pay for a multi band antenna.


Chiming in late on this one...


Mythical attributes aside, I believe the real reason that ladder line
has become more popular is:

1. Almost all rigs are All HF band these days.

2. Many people have just one antenna they can put up at any given
time. Whether it is space considerations, maintaining a low profile
or keeping the XYL happy I remember the discussions with my wife when
I wanted to put up the HF vertical. "Why do you need two antennas?"
"Are you going to transmit two signals at the same time?". Twasn't
easy, and a lot of Hams might lose that argument.

So assuming it is a doublet, and I wanted to run 80 to 10 meters, I'd
put up much wire as I could, not mess with coax, just run ladder line
to a window panel, then into the house, into a tuner that can handle
balanced line. And pay attention to the lengths that might make for
trouble in matching.


Or, put up as much wire as you can, put an autotuner at the feedpoint,
and run coax back to the shack.

probably a six of one, half dozen of the other, depending on what you
already have, what kind of support structures you have (if you are
putting up an inverted V, then supporting the weight of the tuner isn't
an issue..), etc.


Speaking of autotuners, I just got my MFJ933, and have been working
with it this last week. MFJ has an interesting reputation, but I have to
say they pretty much got this one right. For $224, it is one impressive
piece of hardware/programming.

I run my window line directly to the tuner, which was a big selling
point. NOt many other auto tuners have that feature.

Construction was quite acceptable, performance has been fine so far, and
appearance good with only one exception. One of the front panel's
letters had a little rub mark on it. No biggie, just cleaned it with an
eraser.

The analog meter is a little small, but the whole unit would have to be
made bigger to put in a larger one, so that was a tradeoff. It also has
the digital readout, so I find myself looking at the analog meter for
initial reference on a frequency, then at the readout after that. It has
a lot of other features that I'm still learning.

I give the unit an A, at least on my experience so far.

- 73 de Mike N3LI

Michael Coslo wrote in news:h1geb3$do4i$1
@tr22n12.aset.psu.edu:

MFJ933

???

On Jun 19, 11:28�am, Michael Coslo wrote:
Jim Lux wrote:
Mike Coslo wrote:
wrote:

Sure, there are losses with the balun used in most tuners, but I
consider that a price to pay for a multi band antenna.

Chiming in late on this one...

Mythical attributes aside, I believe the real reason that ladder line
has become more popular is:

1. Almost all rigs are All HF band these days.

2. Many people have just one antenna they can put up at any given
time. Whether it is space considerations, �maintaining a low profile
or keeping the XYL happy I remember the discussions with my wife when
I wanted to put up the HF vertical. "Why do you need two antennas?"
"Are you going to transmit two signals at the same time?". Twasn't
easy, and a lot of Hams might lose that argument.

So assuming it is a doublet, and I wanted to run 80 to 10 meters, I'd
put up much wire as I could, not mess with coax, just run ladder line
to a window panel, then into the house, into a tuner that can handle
balanced line. And pay attention to the lengths that might make for
trouble in matching.

Or, put up as much wire as you can, put an autotuner at the feedpoint,
and run coax back to the shack.

probably a six of one, half dozen of the other, depending on what you
already have, what kind of support structures you have (if you are
putting up an inverted V, then supporting the weight of the tuner isn't
an issue..), etc.

Speaking of autotuners, �I just got my MFJ933, and have been working
with it this last week. MFJ has an interesting reputation, but I have to
say they pretty much got this one right. For $224, it is one impressive
piece of hardware/programming.

I run my window line directly to the tuner, which was a big selling
point. NOt many other auto tuners have that feature.

Construction was quite acceptable, performance has been fine so far, and
appearance good with only one exception. One of the front panel's
letters had a little rub mark on it. No biggie, just cleaned it with an
eraser.

The analog meter is a little small, but the whole unit would have to be
made bigger to put in a larger one, so that was a tradeoff. It also has
the digital readout, so I find myself looking at the analog meter for
initial reference on a frequency, then at the readout after that. It has
a lot of other features that I'm still learning.

I give the unit an A, at least on my experience so far.

� � � � - 73 de Mike N3LI- Hide quoted text -

- Show quoted text -

The MFJ-933 is a manual loop tuner according to their catalog. Which
ever one you are using sounds nice, and is worth a look, but I don't
think it is a MFJ-933.

Gary N4AST

Dear N3LI: Might the MFJ model be 993?

73, MAc N8TT

--
J. McLaughlin; Michigan, USA
Home:

"Michael Coslo" wrote in message
...


Speaking of autotuners, I just got my MFJ933, and have been working with
it this last week. MFJ has an interesting reputation, but I have to say
they pretty much got this one right. For $224, it is one impressive piece
of hardware/programming.

I run my window line directly to the tuner, which was a big selling point.
NOt many other auto tuners have that feature.

Construction was quite acceptable, performance has been fine so far, and
appearance good with only one exception. One of the front panel's letters
had a little rub mark on it. No biggie, just cleaned it with an eraser.

The analog meter is a little small, but the whole unit would have to be
made bigger to put in a larger one, so that was a tradeoff. It also has
the digital readout, so I find myself looking at the analog meter for
initial reference on a frequency, then at the readout after that. It has a
lot of other features that I'm still learning.

I give the unit an A, at least on my experience so far.

- 73 de Mike N3LI

J. Mc Laughlin wrote:
Dear N3LI: Might the MFJ model be 993?


Sorry, Germs, I typo'd. It is indeed a 993.

- 73 de Mike N3LI -