Enough already, G5RV, geez
n4...@sccoast.net
This nonsense mskes my skin crawl. Just put up a dipole and feed it
with open wire line and be done with it.
73 Gus N4ZO
W6KKT
Gus, first things first. Go see a doctor for your malaise. When you
are well, you will be more receptive to antenna system theorization.
"Just put up a dipole and feed it with open wire line" ,is not a
cogent argument.
Good luck, Jesse, W6KKT
Cecil Moore
W6KKT wrote:
Gus>This nonsense mskes my skin crawl. Just put up a dipole and feed it
Gus>with open wire line and be done with it.
> "Just put up a dipole and feed it with open wire line" ,is not a
> cogent argument. Good luck, Jesse, W6KKT
Hi Gus and Jess, I didn't see the original posting but let's say I
put up a 123 ft dipole and feed it with 61.5 ft of 450 ohm ladder-
line on 40m. EZNEC sez the system impedance seen at the transmitter
end is 3524+j2141. Gus, please take it from there. How are you
going to match that balanced impedance to 50 ohms unbalanced?
73, Cecil, W6RCA, OOTC
W6KKT
Hi Cecil, as you already know, using 450 ohm ladder-line (tuned
feeders) requires much fore-thought, especially so, if one uses an
amplifier. Feed-line/tuner impedance transformation, efficiency,
tuner component V&I breakdown, etc; are all considered when using
tuned feeders. It is not an easy task to efficiently match a
multi-band tuned feeder antenna system. Fantastic luck, trial &
error, or a working knowledge of the "Smith Chart" is required.
Cecil, your threads, and helpful ideas about tuned feeders, and
matching, is much appreciated at this station.
73, Jesse, W6KKT
Reynolds
Jesse,
I think Gus has a good point. Why not answer his specific observation
relative to
feeding a dipole with only ladder line rather than the combination of
ladder line and
coax (G5RV).
Thanks.
Paul, W2CW
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
=======W6KKT <w6...@frazmtn.com> wrote in article
<3316d34c...@news.frazmtn.com>...
> On Fri, 28 Feb 1997 02:41:35 GMT, n4...@sccoast.net wrote:
>
> >This nonsense mskes my skin crawl. Just put up a dipole and feed it
> >with open wire line and be done with it.
> >
> >73 Gus N4ZO
>
> Gus, first things first. Go see a doctor for your malaise. When you
> are well, you will be more receptive to antenna system theorization.
>
Charles Rauch
On Fri, 28 Feb 1997 02:41:35 GMT, n4...@sccoast.net wrote:
>This nonsense mskes my skin crawl. Just put up a dipole and feed it
>with open wire line and be done with it.
>
>73 Gus N4ZO
>I think Gus has a good point. Why not answer his specific observation
>relative to
>feeding a dipole with only ladder line rather than the combination of
>ladder line and
>coax (G5RV).
OK, let me try to answer his "specific observation". First about the
skin, try Skin-so-soft or the delete - ignore thread key. :-)
"Just putting up a dipole and feeding it with open wire" isn't any
kind of solution. As Cecil and Jessie pointed out, the system might
just provide an unmatchable impedance.
73 Tom
Reynolds
Charles Rauch <W8J...@worldnet.att.net> wrote in article
<3317deec...@netnews.worldnet.att.net>...
> On Fri, 28 Feb 1997 02:41:35 GMT, n4...@sccoast.net wrote:
>
> >This nonsense mskes my skin crawl. Just put up a dipole and feed it
> >with open wire line and be done with it.
> >
> >73 Gus N4ZO
>
> >I think Gus has a good point. Why not answer his specific observation
> >relative to
> >feeding a dipole with only ladder line rather than the combination of
> >ladder line and
> >coax (G5RV).
>
>
> "Just putting up a dipole and feeding it with open wire" isn't any
> kind of solution. As Cecil and Jessie pointed out, the system might
> just provide an unmatchable impedance.
>
> 73 Tom
Tom.
Yes, there is that possibility but so is there with ladder line/ coax
combination unless
one attempts to match the combination which would have to be done when
planning
the dipole fed with ladder alone. Again I dont think the question Guss
raised has
been answered.
Besides, Cecil has suggested using ladder line all the way.
73 Paul
Steve Ellington
n4...@sccoast.net wrote:
>
> This nonsense mskes my skin crawl. Just put up a dipole and feed it
> with open wire line and be done with it.
>
> 73 Gus N4ZO
Yea, just get one of those super duper tuners that eat up 30% or more
or your power and feed that sucker. So what's a few db's anyway?
73 N4LQ
W6KKT
On 1 Mar 1997 13:48:51 GMT, "Reynolds" <reyn...@capital.net> wrote:
>
>
>Charles Rauch <W8J...@worldnet.att.net> wrote in article
><3317deec...@netnews.worldnet.att.net>...
>> On Fri, 28 Feb 1997 02:41:35 GMT, n4...@sccoast.net wrote:
>>
>> >This nonsense mskes my skin crawl. Just put up a dipole and feed it
>> >with open wire line and be done with it.
>> >
>> >73 Gus N4ZO
>>
>> >I think Gus has a good point. Why not answer his specific observation
>> >relative to
>> >feeding a dipole with only ladder line rather than the combination of
>> >ladder line and
>> >coax (G5RV).
>>
>>
>> "Just putting up a dipole and feeding it with open wire" isn't any
>> kind of solution. As Cecil and Jessie pointed out, the system might
>> just provide an unmatchable impedance.
>>
>> 73 Tom
>
>Tom.
>
>Yes, there is that possibility but so is there with ladder line/ coax
>combination unless
>one attempts to match the combination which would have to be done when
>planning
>the dipole fed with ladder alone. Again I dont think the question Guss
>raised has
>been answered.
>
>Besides, Cecil has suggested using ladder line all the way.
>
>73 Paul
Paul, Several times you have stated what hasn't been answered. Why
don't you answer "gus's" question in the form you think is proper?
73, Jesse, W6KKT
Cecil Moore
W6KKT wrote:
> Paul, Several times you have stated what hasn't been answered. Why
> don't you answer "gus's" question in the form you think is proper?
> 73, Jesse, W6KKT
Hi Jess, I just went back and looked at the original posting. Here it
is and it doesn't have a question in it at all.
"This nonsense mskes my skin crawl. Just put up a dipole and feed it
with open wire line and be done with it."
73, Cecil, W6RCA, OOTC
Reynolds
W6KKT <w6...@frazmtn.com> wrote in article
<331859c...@news.frazmtn.com>...
> On 1 Mar 1997 13:48:51 GMT, "Reynolds" <reyn...@capital.net> wrote:
>
> >
> >
> >Charles Rauch <W8J...@worldnet.att.net> wrote in article
> ><3317deec...@netnews.worldnet.att.net>...
> >> On Fri, 28 Feb 1997 02:41:35 GMT, n4...@sccoast.net wrote:
> >>
> >> >This nonsense mskes my skin crawl. Just put up a dipole and feed it
> >> >with open wire line and be done with it.
> >> >
> >> >73 Gus N4ZO
> >
> >Yes, there is that possibility but so is there with ladder line/ coax
> >combination unless
> >one attempts to match the combination which would have to be done when
> >planning
> >the dipole fed with ladder alone. Again I dont think the question Guss
> >raised has
> >been answered.
> >
> >Besides, Cecil has suggested using ladder line all the way.
> >
> >73 Paul
>
> Paul, Several times you have stated what hasn't been answered. Why
> don't you answer "gus's" question in the form you think is proper?
> 73, Jesse, W6KKT
Jesse,
The reason I am not answering the question is that Guss's question is one I
might
have asked myself because I don't know the answer. Since there are many
folks
on the newsgroup who might know I thought it would be proper to chime in to
enlist a response. I know that one of the articles written by G5RV
mentioned using
ladder line all the way because it was more efficient.
Cecil's recomendation to use ladder line all the way also suggest there is
something
to Guss's question.
So, what is the answer to Guss's question?
Thanks.
Paul
Lew McCoy
W6KKT wrote:
>
> On Fri, 28 Feb 1997 08:26:11 -0700, Cecil Moore
> <cecil_...@ccm.ch.intel.com> wrote:
>
> >W6KKT wrote:
> >Gus>with open wire line and be done with it.
> >
> >> "Just put up a dipole and feed it with open wire line" ,is not a
> >> cogent argument. Good luck, Jesse, W6KKT
> >
> >put up a 123 ft dipole and feed it with 61.5 ft of 450 ohm ladder-
> >line on 40m. EZNEC sez the system impedance seen at the transmitter
> >end is 3524+j2141. Gus, please take it from there. How are you
> >going to match that balanced impedance to 50 ohms unbalanced?
> >
> >73, Cecil, W6RCA, OOTC
>
> Hi Cecil, as you already know, using 450 ohm ladder-line (tuned
> feeders) requires much fore-thought, especially so, if one uses an
> amplifier. Feed-line/tuner impedance transformation, efficiency,
> tuner component V&I breakdown, etc; are all considered when using
> tuned feeders. It is not an easy task to efficiently match a
> multi-band tuned feeder antenna system. Fantastic luck, trial &
> error, or a working knowledge of the "Smith Chart" is required.
> Cecil, your threads, and helpful ideas about tuned feeders, and
> matching, is much appreciated at this station.
open wire line and put it up and forget". While I have never said that
exactly lord knows I have preached open wire fed dipoles for years.
However, you are right but the problem is educating the hams on how to
use such installations. Just recently, I had put up a "McCoy" dipole,
never bothered to measure the length but somewhere around 300 feet--when
I went on 160 I had a horrendous load in the station--naturally I knew
how to correct it but but bottom line--you are correct.
Lew McCoy
Paul Mooney
>> >Gus>This nonsense mskes my skin crawl. Just put up a dipole and feed it
>> >Gus>with open wire line and be done with it.
>> >
I agree with the sentiments expressed in this comment.
This list should only contain messages that *I* want to read.
Paul
Bart Rowlett
In article <3317deec...@netnews.worldnet.att.net>,
Charles Rauch <W8J...@worldnet.att.net> wrote:
>>I think Gus has a good point. Why not answer his specific observation
>>relative to
>>feeding a dipole with only ladder line rather than the combination of
>>ladder line and
>>coax (G5RV).
>
>"Just putting up a dipole and feeding it with open wire" isn't any
>kind of solution. As Cecil and Jessie pointed out, the system might
>just provide an unmatchable impedance.
>
I think the 'unmatchable impedance" problem is more common than not. Even
when the antenna is well balanced and common mode feedline currents are
under control, my experience is an arbitrary combination of feedline
and radiator will almost never feed well on more than one or two bands.
Either the impedance will be unmatchable, at least using a typical commercial
tuner or there will be excessive voltage and arcing somewhere. In some
cases it simply won't 'get out' (transmit efficiently) usually due to losses
in the tuner, feedline or balun. There is no substitute for having a decent
understanding of the basics of antennas, feedline and matching network
concepts. Even a simple multiband antenna with a feedline is a fairly
complicated system with plenty of interactions between the radiator,
feedline, matching network and rig. A basic understanding of the concepts
forces an awareness of the the various tradeoffs and compromises which
are inevitable. Once 'the facts of life' (or at least antennas) are
recognized, a careful design can usually be found which optimizes those
parameters which are necessary or important for others less useful in your
particular installation.
The recent availability of low cost computational and measurement tools
such as EZNEC and the Autek RF-1 impedance analyzer makes it possible for
the average ham to finally design and implement an optimized antenna
system for his particular situation.
In an attempt to guarantee at least mediocre performance, many
commercially available antenna systems make a number of compromises
which wouldn't be necessary if the user were capable and willing to make
a few adjustments as required to accomodate the particulars of his station
environment. That's for the well designed commercial systems, the poor
ones are sometimes abysmal. The recent availability of computational and
measurement tools such as EZNEC and the Autek RF-1 impedance analyzer has
made it possible for nearly any interested amateur to understand what is
possible for his station considering his budget and environmental constraints.
bart wb6hqk
W6KKT
On 1 Mar 1997 18:22:28 GMT, "Reynolds" <reyn...@capital.net> wrote:
he reason I am not answering the question is that Guss's question
isone I
>might
>have asked myself because I don't know the answer. Since there are many
>folks
>on the newsgroup who might know I thought it would be proper to chime in to
>enlist a response. I know that one of the articles written by G5RV
>mentioned using
>ladder line all the way because it was more efficient.
>
>Cecil's recomendation to use ladder line all the way also suggest there is
>something
>to Guss's question.
>
>So, what is the answer to Guss's question?
>
>Thanks.
>
>Paul
>
>
Hi Paul, yes! The most efficient way to feed a flat-top G5RV (not
inverted V) is to use open wire line or "ladder line" all the way to
the tuner. In the standard configuration, the G5RV using 33' 300ohm
line section to coax, in most cases will require a tuner for solid
state rigs. Most of the system loss will be due to the swr and
dielectric loss in the coax, depending on it's length to the tuner. On
10meters the loss can be quite high. The most efficient feed system
is the open-wire or ladder line to the tuner. When using "tuned
feeder" the length of the line is adjusted to the configuration of the
tuner, and not just the run to the shack.
For the last ninety day's I have been testing a G5RV flat top, fed
with 175' 450 ohm ladder line. The tuner is a home brew, ganged dual
roller coil, balanced "L" tuner. I first tried 145' of line to the
tuner, but I had too much rf voltage on some of the bands. The
variable capacitor would arc over when using my amp. So, I adjusted
the line length to have a lower impedance to the tuner on most bands.
The tuner is relatively cold to RF voltage and heat, with 1.5KW pumped
into it.
I only use the G5RV on 80/40. It is a very competitive system in the
80/40 meter DX windows.
73, Jesse, W6KKT
Geoffrey S. Mendelson
Paul, W2CW wrote:
: I think Gus has a good point. Why not answer his specific observation
: relative to
: feeding a dipole with only ladder line rather than the combination of
: ladder line and
: coax (G5RV).
I think I am the culprit behind this thread. Without repeating myself, I
am in ISRAEL. Great place if you want kosher food etc, lousy place if
you want ladder line. There are no amateur radio stores, no Radio
Shacks, etc. I can get all the 75 ohm TV coax I want. All the short
towers, narrowband TV yagi's, etc.
Things like ladder line, 300 ohm twinlead, insulators, BALUNS, MFJ (or
any other brand) tuners, transceivers (require a permit), etc must be
ordered from the US or Europe. Once they get here, I have to take off
time from work to go argue with the meches (import tax) people to get it
out of hock.
The only reason I asked about the G5RV, is that I had brough some
insulators, used rg8x and 300 ohm twinlead with me. If not, it would
have been a wire dipole feed with 75ohm tv coax.
So I was interested in the G5RV as a comprimise using the materials I had
on hand.
73,
Geoff.
--
Geoffrey S. Mendelson (4X/N3OWJ), Senior Programmer
Computer Science Institute, Hebrew University, Jerusalem, Israel
geo...@cs.huji.ac.il (02) 65 85692 Fax (02) 561 7723
To get pgp public key: "finger geo...@cs.huji.ac.il"
Tom Rauch
On 2 Mar 1997 08:41:56 GMT, geo...@cs4.cs.huji.ac.il (Geoffrey S.
Mendelson) wrote:
>The only reason I asked about the G5RV, is that I had brough some
>insulators, used rg8x and 300 ohm twinlead with me. If not, it would
>have been a wire dipole feed with 75ohm tv coax.
>
>
>So I was interested in the G5RV as a comprimise using the materials I had
>on hand.
Geoff,
This is a discussion group about antennas. If anyone is discussing
something directly about an antenna or part of an antenna system, it
fits the charter of this newsgroup to the letter.
There is absolutely no reason for you to explain why you asked a valid
question. ***Questions like yours are the reason newsgroup was
created. ***
In my opinion, you didn't owe anyone else an explaination. N4ZO needs
to learn how to use his delete key.
73 Tom
Reynolds
W6KKT <w6...@frazmtn.com> wrote in article
<3318e038...@news.frazmtn.com>...
>> >
> Hi Paul, yes! The most efficient way to feed a flat-top G5RV (not
> inverted V) is to use open wire line or "ladder line" all the way to
> the tuner. In the standard configuration, the G5RV using 33' 300ohm
> line section to coax, in most cases will require a tuner for solid
> state rigs. Most of the system loss will be due to the swr and
> dielectric loss in the coax, depending on it's length to the tuner. On
> 10meters the loss can be quite high. The most efficient feed system
> is the open-wire or ladder line to the tuner. When using "tuned
> feeder" the length of the line is adjusted to the configuration of the
> tuner, and not just the run to the shack.
> For the last ninety day's I have been testing a G5RV flat top, fed
> with 175' 450 ohm ladder line. The tuner is a home brew, ganged dual
> roller coil, balanced "L" tuner. I first tried 145' of line to the
> tuner, but I had too much rf voltage on some of the bands. The
> variable capacitor would arc over when using my amp. So, I adjusted
> the line length to have a lower impedance to the tuner on most bands.
> The tuner is relatively cold to RF voltage and heat, with 1.5KW pumped
> into it.
> I only use the G5RV on 80/40. It is a very competitive system in the
> 80/40 meter DX windows.
> 73, Jesse, W6KKT
>
Hello Jesse,
Well, I think we are back to Guss's question/comment (less the skin
problem).
From what I have gathered from you and Cecil that feeding a dipole
(universal
dipole, all band, G5RV etc.) with ladder line rather than a combination of
ladder
line and coax will produce a more efficient multi-band antenna system even
though a balun-tuner combination is required to match the output of todays
transceivers.
In each case, one must attempt to adjust the feed line length so that the
tuner-balun
combination can handle what the line presents to it with the minimum loss.
I think
here is where the catch is. Right?
I have been having difficulties accepting the G5RV feed design as the best
we can do
for a multi-band antenna. Especially, when everything I read indicates
that the design is really intended for the best efficiency on 20m. All
other bands a comprise and where a tuner-balun combination is required
anyway. (balun at the ladder line
coax junction).
Why bother with the G5RV configuration? I know many people feel
uncomfortable
with running ladder into their house making the coax of the G5RV more
attractive
to some. My perspective is to deal with the ladder line in the house if my
antenna
system can be made more efficient. How much???
Another related subject. The recent QST evaluation of antenna tuners. I
not sure,
but some how I dont think the author/s have brought the tuner efficiency
into the contexts of what a tuner would have to match on a well thought out
multi-band antenna. (c.f. dipole with ladder line). For example: avoiding
3 ohm matches
etc..
All comments welcome. 73 Paul, W2CW
Cecil Moore
Reynolds wrote:
> From what I have gathered from you and Cecil that feeding a dipole
> (universal dipole, all band, G5RV etc.) with ladder line rather than a
> combination of ladder line and coax will produce a more efficient multi-
> band antenna system even though a balun-tuner combination is required
> to match the output of todays transceivers.
Hi Paul, correct except to convey the concept, one should say "...even
though a balun function and tuner function are required..." Let's talk
about functions instead of black box objects called baluns and tuners.
I vary the length of my ladder-line so I can use a single parallel
capacitor across the ladder-line to fulfill the tuner function. No
other tuner is required!! I don't know anything more efficient at
the tuner function than a single high-Q capacitor which *is* my
balanced tuner. The effect of the capacitor is to present a purely
resistive 200 ohms to my 4:1 balun which is extremely efficient when
it sees its design impedance of 200 ohms resistive. My transceiver sees
a near-perfect 50 ohms. This matching system is virtually lossless. It
is certainly more efficient than any coax system with its matched line
losses and that includes half-wave dipoles fed with ordinary coax.
If one divides the ladder-line Z0 by the SWR, one gets the lowest
resistance existing on the transmission line at the Imax (current
loop). 450/9=50 so if the 450 ohm SWR is above 9, a perfect 50
ohms can be achieved with a single capacitor. I call it the PC-50
point. The reason I chose the PC-200 points is that my 450 ohm SWR is
less than 9:1 on some bands and therefore 50 ohms is unobtainable
using a single capacitor. I can obtain a perfect 200 ohms if the SWR
is higher than 2.25:1 and it is with my 102 ft dipole.
I have been hammering these points for over a year and more and more
people are taking me seriously. Ladder-line is a near-perfect choice
for a balanced antenna. Its use results in the most efficient antenna/
feedline system that we know and it works on all-HF-band dipoles. It
moves all the problems back down to the operating position where there
are a number of near-perfect solutions.
73, Cecil, W6RCA, OOTC
Steve
Is it correct to call the antenna a G5RV if open wire line is used all
the way to the tuner? What makes it a G5RV, the feed arrangement (33'
of ladder line to coax) combined with a 102' element or is it any
antenna that is fed in the center, by any means, that is 102'?
W6KKT wrote:
>
> On 1 Mar 1997 18:22:28 GMT, "Reynolds" <reyn...@capital.net> wrote:
>
> he reason I am not answering the question is that Guss's question
> isone I
> >might
> >have asked myself because I don't know the answer. Since there are many
> >folks
> >on the newsgroup who might know I thought it would be proper to chime in to
> >enlist a response. I know that one of the articles written by G5RV
> >mentioned using
> >ladder line all the way because it was more efficient.
> >
> >Cecil's recomendation to use ladder line all the way also suggest there is
> >something
> >to Guss's question.
> >
> >So, what is the answer to Guss's question?
> >
> >Thanks.
> >
> >Paul
> >
> >
Tom Rauch
On 2 Mar 1997 23:51:30 GMT, "Reynolds" <reyn...@capital.net> wrote:
>Another related subject. The recent QST evaluation of antenna tuners. I
>not sure,
>but some how I dont think the author/s have brought the tuner efficiency
>into the contexts of what a tuner would have to match on a well thought out
>multi-band antenna. (c.f. dipole with ladder line). For example: avoiding
>3 ohm matches
>etc..
>
>All comments welcome. 73 Paul, W2CW
Hi Paul,
The QST efficiency measurements you refer to are grossly incorrect as
published, so don't rely on the values published to determine system
efficiency.
The overall trend of a T network tuner is to have increased loss
driving a low impedance load, or a load with a high equiv value of
series capacitive reactance with the load.
Low resistance load impedances, especially with high values of series
capacitive reactance, do cause problems.
73 Tom
William E. Sabin
William E. Sabin wrote:
>
> W6KKT wrote:
>
> > In your opinion, what is the correct terminology for a 102' center-fed
> > when used on 20 meters?
>
> How about three half waves (pretty close), collinear and current fed at
> the center.
>
Correction: not collinear. A center fed harmonic antenna would be better.
Bill W0IYH
Lew McCoy
Tom: I have to chuckle about this argument simply because when I have
written--so many times--about this problem I constantly warned hams
about the loads. However, I am beginning to believe no matter what we
say here is going to fall on receptive ears.
Lew McCoy
Lew McCoy
W6KKT wrote:
>
> On Mon, 03 Mar 1997 12:17:01 -0800, Steve <theb...@erols.com> wrote:
>
> >Is it correct to call the antenna a G5RV if open wire line is used all
> >the way to the tuner? What makes it a G5RV, the feed arrangement (33'
> >of ladder line to coax) combined with a 102' element or is it any
> >antenna that is fed in the center, by any means, that is 102'
>
> the word "G5RV", when communicating the performance difference between
>
> G5RV feeder systems. If I wasn't trying to make a point concerning
> G5RVs I would probably use the term "102' center fed with ladder- line
> feeders". However, as far as I know, G5RV made the 102' length
> famous. And, it is not a magic number.
> In your opinion, what is the correct terminology for a 102' center-fed
> when used on 20 meters?
>
> I posted the true description quoted from the RSGB Handbook. Varney,
G5RV, described his orignial antenna as 102 foot dipole, fed with 300
ohm line down to a tuner. Because he had so many requests for that
antenna--fe with coax he modified the system to use rg8 type cable from
teh tuner connected the 300 ohm line--he did specify 300 to 600 ohm open
wire line feeders. His original 120 foot dipole was designed primarily
as a 20 meter antenna.
Lew McCoy, W1ICP
William E. Sabin
W6KKT wrote:
>
> The point I was trying to make was, it is
> not a dipole. "Center fed harmonic, 102' center fed wire, center fed
> wire, etc. are all correct.
> As you know, a "dipole" is a wire approximately 1/2 the transmitted
> wavelength. And, I might add, when fed properly, one of the more
> efficient antenna's.
My problem with a fixed dipole is its directivity broadside and nothing
(well, nothing much) doing off the ends. Now, a half wave dipole at 150
feet height on 80 meters, with a rotator, that is different!
Bill W0IYH
William E. Sabin
W6KKT wrote:
> In your opinion, what is the correct terminology for a 102' center-fed
> when used on 20 meters?
How about three half waves (pretty close), collinear and current fed at
the center.
Bill W0IYH
W6KKT
On Mon, 03 Mar 1997 12:17:01 -0800, Steve <theb...@erols.com> wrote:
>Is it correct to call the antenna a G5RV if open wire line is used all
>the way to the tuner? What makes it a G5RV, the feed arrangement (33'
>of ladder line to coax) combined with a 102' element or is it any
>antenna that is fed in the center, by any means, that is 102'
Yes. It is correct when "posting" in a G5RV discussion group to use
the word "G5RV", when communicating the performance difference between
G5RV feeder systems. If I wasn't trying to make a point concerning
G5RVs I would probably use the term "102' center fed with ladder- line
feeders". However, as far as I know, G5RV made the 102' length
famous. And, it is not a magic number.
In your opinion, what is the correct terminology for a 102' center-fed
when used on 20 meters?
W6KKT
W6KKT
>William E. Sabin wrote:
>>
>> W6KKT wrote:
>>
>> > In your opinion, what is the correct terminology for a 102' center-fed
>> > when used on 20 meters?
>>
>> How about three half waves (pretty close), collinear and current fed at
>> the center.
>>
>Correction: not collinear. A center fed harmonic antenna would be better.
>
>Bill W0IYH
Hi Bill, you are correct. The point I was trying to make was, it is
not a dipole. "Center fed harmonic, 102' center fed wire, center fed
wire, etc. are all correct.
As you know, a "dipole" is a wire approximately 1/2 the transmitted
wavelength. And, I might add, when fed properly, one of the more
efficient antenna's.
Respectfully, Jesse, W6KKT
W6KKT
On Mon, 03 Mar 1997 18:30:04 -0800, "William E. Sabin"
<sab...@crpl.cedar-rapids.lib.ia.us> wrote:
>
>My problem with a fixed dipole is its directivity broadside and nothing
>(well, nothing much) doing off the ends. Now, a half wave dipole at 150
>feet height on 80 meters, with a rotator, that is different!
>
>Bill W0IYH
Hi Bill, Yes, I agree. At present I'm testing a 102'/center fed/
ladder-line combo, up 100' both ends. I't is used exclusively on
75/40m On 75m it exhibits more gain at lower angles than many full
size 1/2 or 1/4 vertical systems with extensive radials. On 40m it has
more gain than many "4square" systems. On 40m, during the recent dx
contest, I received many, many unsolicited, positive comments from dx
stations about how strong my signal was compared to other W6s. I
realize, not many Amateurs have the tree's to put up dipoles at 100'.
It sure is fun when you do. Now, if I could only rotate my tree's.
Respectfully, Jesse, W6KKT .
-=Tony=-
In <331b63a...@news.frazmtn.com> w6...@frazmtn.com (W6KKT )
writes:
>On Mon, 03 Mar 1997 16:34:46 -0800, "William E. Sabin"
><sab...@crpl.cedar-rapids.lib.ia.us> wrote:
>
>>William E. Sabin wrote:
>>>
>>> W6KKT wrote:
>>>
>>> > In your opinion, what is the correct terminology for a 102'
center-fed
>>> > when used on 20 meters?
>>>
>>> How about three half waves (pretty close), collinear and current
fed at
>>> the center.
>>>
>>Correction: not collinear. A center fed harmonic antenna would be
better.
>>
>>Bill W0IYH
>Hi Bill, you are correct. The point I was trying to make was, it is
>not a dipole. "Center fed harmonic, 102' center fed wire, center fed
>wire, etc. are all correct.
>As you know, a "dipole" is a wire approximately 1/2 the transmitted
>wavelength. And, I might add, when fed properly, one of the more
>efficient antenna's.
>Respectfully, Jesse, W6KKT
>
>
Jesse-
Man, do I agree with you! I might be inclined, though, to further
define a G5RV as a center-fed balanced pair of wires whose overall
length is carefully selected to optimally set reasonable matching
conditions over a number of ham bands. <too much a mouthful> <g>
Obviously, this says nothing about the radiation patterns which is a
much different subject again.
Relinquishing the whole concept of a dipole to any pair of
balanced wires (as some luminaries have insisted) is fallacious in
my view.
-=Tony=- W6ANV
Tom Rauch
On Tue, 04 Mar 1997 00:11:02 GMT, w6...@frazmtn.com (W6KKT ) wrote:
>Hi Bill, you are correct. The point I was trying to make was, it is
>not a dipole. "Center fed harmonic, 102' center fed wire, center fed
>wire, etc. are all correct.
>As you know, a "dipole" is a wire approximately 1/2 the transmitted
>wavelength. And, I might add, when fed properly, one of the more
>efficient antenna's.
>Respectfully, Jesse, W6KKT
Hi Jessie,
Looking in Jasik's index under "dipole antennas" I find listed:
Asymmetrical, biconical, collinear, cylindrical, electric, fan,
folded, full-wave, half-wave, sleeve, triangular, and vertical types.
Looking at the IRE Standard on Antennas (1948) it says:
"A dipole antenna is a straight radiator, usually fed in the center,
and producing a maximum of radiation in a plane normal to the axis.
The length specified is the overall length."
I use my 80 meter dipole on 160, since it is a full size half wave on
that band, and my 80 meter half-wave dipole on 80 since it is a 40
meter dipole. My 20 meter collinear dipole antenna is a 40 meter
half-wave dipole fed with open wire line, and I use it as a 20 meter
dipole on 40 also.
I hope that straightens any confusion out.
73 Tom
Roy Lewallen
In article <331AF0...@ccm.ch.intel.com>,
Cecil Moore <cecil_...@ccm.ch.intel.com> wrote:
>I have been hammering these points for over a year and more and more
>people are taking me seriously. Ladder-line is a near-perfect choice
>for a balanced antenna. Its use results in the most efficient antenna/
>feedline system that we know and it works on all-HF-band dipoles. It
>moves all the problems back down to the operating position where there
>are a number of near-perfect solutions.
Cecil, have you ever measured the loss of wet ladder line? Years ago I
measured some twinlead when it was dry and wet. At 21 MHz, 100 feet
measured 0.8 dB dry (about the same as RG-8 foam-insulated line), and 3.7
dB wet (about twice the loss in dB of RG-58). It had been outside for a
couple of weeks before the rain, so had probably gotten a bit dusty. After
it was well washed but still wet, the loss dropped to 1.5 dB. (See QST
"Technical Correspondence", Feb. 1982.) Ladder line might be a better
choice for you folks in Arizona than for us Oregon mossbacks.
Roy Lewallen, W7EL
W6KKT
On Tue, 04 Mar 1997 03:51:57 GMT, W8J...@worldnet.att.net (Tom Rauch)
wrote:
>Hi Jessie,
>
>Looking in Jasik's index under "dipole antennas" I find listed:
>
>Asymmetrical, biconical, collinear, cylindrical, electric, fan,
>folded, full-wave, half-wave, sleeve, triangular, and vertical types.
>
>Looking at the IRE Standard on Antennas (1948) it says:
>
>"A dipole antenna is a straight radiator, usually fed in the center,
>and producing a maximum of radiation in a plane normal to the axis.
>The length specified is the overall length."
>I use my 80 meter dipole on 160, since it is a full size half wave on
>that band, and my 80 meter half-wave dipole on 80 since it is a 40
>meter dipole. My 20 meter collinear dipole antenna is a 40 meter
>half-wave dipole fed with open wire line, and I use it as a 20 meter
>dipole on 40 also.
>
>I hope that straightens any confusion out.
>
>73 Tom
Thanks Tom. I still stand by my statement; a 102' center fed wire is
not a dipole when operated 14mhz and above.
My 1955 Amateur Radio Handbook states: :"The fundamental form of
antenna is a single wire whose length is approximately equal to half
the transmitting wavelength. It is the unit from which many
more-complex forms of antennas are constructed. It is known as a
dipole or Hertz antenna." The 1993 ARRL Handbook (page 17-3) states
the same thing. In fact, the only formula I have ever seen for a
"dipole" is; 492xK/Fmhz. I think it is misleading to call a collinear
a dipole.
Respectfully, Jesse, W6KKT
W6KKT
On Tue, 04 Mar 97 08:48:35 GMT, w7...@teleport.com (Roy Lewallen) wrote
>
>Cecil, have you ever measured the loss of wet ladder line? Years ago I
>measured some twinlead when it was dry and wet. At 21 MHz, 100 feet
>measured 0.8 dB dry (about the same as RG-8 foam-insulated line), and 3.7
>dB wet (about twice the loss in dB of RG-58). It had been outside for a
>couple of weeks before the rain, so had probably gotten a bit dusty. After
>it was well washed but still wet, the loss dropped to 1.5 dB. (See QST
>"Technical Correspondence", Feb. 1982.) Ladder line might be a better
>choice for you folks in Arizona than for us Oregon mossbacks.
>
>Roy Lewallen, W7EL
Roy, what about open-wire line?
Respectfully, Jesse, W6KKT
Chuck (Jack) Hawley
I went to open wire line to get away from the effects of water on the
dielectric. I use #14 spaced 4 inches with spreaders made out of 1/4 X
1/4 inch lexan every 2.5 feet. I do not have to retune when it rains as
I did before.
Chuck, KE9UW
Lew McCoy
Roy Lewallen wrote:
>
> In article <331AF0...@ccm.ch.intel.com>,
> Cecil Moore <cecil_...@ccm.ch.intel.com> wrote:
>
> >I have been hammering these points for over a year and more and more
> >people are taking me seriously. Ladder-line is a near-perfect choice
> >for a balanced antenna. Its use results in the most efficient antenna/
> >feedline system that we know and it works on all-HF-band dipoles. It
> >moves all the problems back down to the operating position where there
> >are a number of near-perfect solutions.
>
> measured some twinlead when it was dry and wet. At 21 MHz, 100 feet
> measured 0.8 dB dry (about the same as RG-8 foam-insulated line), and 3.7
> dB wet (about twice the loss in dB of RG-58). It had been outside for a
> couple of weeks before the rain, so had probably gotten a bit dusty. After
> it was well washed but still wet, the loss dropped to 1.5 dB. (See QST
> "Technical Correspondence", Feb. 1982.) Ladder line might be a better
> choice for you folks in Arizona than for us Oregon mossbacks.
>
favor of of open wire feeders to a multiband dipole for over 40 years
However, with some success--so don't feel bad--I guarantee you are ont
the right track--and Roy, I made similar checks with many types of open
wire line. The "ladder" line was far from perfect--but with even two
inch open wire line--no really appreciable losses. All this information
I had in the early ARRL Antenna Handbooks. Getting back to that tuner
article in this QST--I again set up tests with the MFJ unit and with 8
or 10 to 1 SWRsno noticeable losses. I realized something else when you
study that article--who in the world would use an SWR of 15 to 1 in coax
on 160--that is ridiculous??
Lew McCoy, W1ICP
Cecil Moore
Roy Lewallen wrote:
> Cecil, have you ever measured the loss of wet ladder line?
> choice for you folks in Arizona than for us Oregon mossbacks.
Hi Roy, it rains 10 inches a year here mostly from thunderstorms
during which I dare not operate anyway. Queen Creek, AZ is a
perfect place to use ladder-line. Next time it rains, in about
three months, I'll try to hurry and measure it cuz it will be
dry in ten minutes. :-)
73, Cecil, W6RCA, OOTC
Cecil Moore
Lew McCoy wrote:
> ...--who in the world would use an SWR of 15 to 1 in coax
> on 160--that is ridiculous?? Lew McCoy, W1ICP
Hi Lew, I'd be willing to bet a beer that, while you were typing
your response, some ham, somewhere, was trying to operate 160m
with an 80m dipole fed with RG-58. :-)
73, Cecil, W6RCA, OOTC
Lew McCoy
Remember years ago I gave a lecture out your way and I pointed out the
losses in rg58 and gave an example of what I would not recommend and
that was using an 80 meter coax fed halfwave on 40 meter as the SWR
would be sky high. A kid in the front row raised his hand and said that
was exactly what he was using and he worked out pretty well--he had no
way of measuring the SWR so he was happy as a clam in you know what. I
said at that time--"Then use McCoy's rule--if the damn thing works,
don't change it!"
Lew McCoy
Roy Lewallen
In article <331c2551...@news.frazmtn.com>,
w6...@frazmtn.com (W6KKT ) wrote:
>[Regarding my question about the loss of ladder line when wet}
>Roy, what about open-wire line?
I don't know about the loss of either ladder line or open wire line when
wet -- all I've measured is twinlead. It seems to me, though, that people
using the stuff would want to make a couple of measurements. I should be
surprised that no one seems to have done this, but somehow I'm not.
Roy Lewallen, W7EL
Cecil Moore
Roy Lewallen wrote:
> I should be
> surprised that no one seems to have done this, but somehow I'm not.
Hi Roy, as you know I change the length of my 450 ohm ladder-line
and use a single door-knob capacitor to cover the entire 40m band
with a 1:1 SWR so my 40m capacitance is fixed and my ladder-line
length is fixed. It does rain here occasionally without lightning
and my SWR doesn't change noticably when the ladder-line is wet.
The holes in the ladder-line would discourage puddling of water as
happens with TV twin lead laying horizontally. So I don't think
rain is a problem with 450 ohm ladder-line. Ice, however, could be
an entirely different matter but I have absolutely no way of causing
ice on my feedline. :-)
73, Cecil, W6RCA, OOTC
Dan K6MHE
[snip]
>
>I think I am the culprit behind this thread. Without repeating myself, I
>am in ISRAEL. Great place if you want kosher food etc, lousy place if
>you want ladder line. There are no amateur radio stores, no Radio
>Shacks, etc. I can get all the 75 ohm TV coax I want. All the short
>towers, narrowband TV yagi's, etc.
>
>Things like ladder line, 300 ohm twinlead, insulators, BALUNS, MFJ (or
>any other brand) tuners, transceivers (require a permit), etc must be
>ordered from the US or Europe. Once they get here, I have to take off
>time from work to go argue with the meches (import tax) people to get it
>out of hock.
>
[SNIP]
>
>73,
>
>Geoff.
>
>--
>Geoffrey S. Mendelson (4X/N3OWJ), Senior Programmer
>Computer Science Institute, Hebrew University, Jerusalem, Israel
>geo...@cs.huji.ac.il (02) 65 85692 Fax (02) 561 7723
>To get pgp public key: "finger geo...@cs.huji.ac.il"
>
Geoff,
If it all that much trouble why not build your own open ladder line?
You can use any resonable plastic material for the spreaders.
That is of course if you don't have wire obtianable there then I
suggest you move.
73
Danny, K6MHE
Roy Lewallen
In article <331D8C...@zianet.com>, Lew McCoy <mc...@zianet.com> wrote:
>I am sure you are right and I bet that sucker is getting out!
>Remember years ago I gave a lecture out your way and I pointed out the
>losses in rg58 and gave an example of what I would not recommend and
>that was using an 80 meter coax fed halfwave on 40 meter as the SWR
>would be sky high. A kid in the front row raised his hand and said that
>was exactly what he was using and he worked out pretty well--he had no
>way of measuring the SWR so he was happy as a clam in you know what. I
>said at that time--"Then use McCoy's rule--if the damn thing works,
>don't change it!"
>
>Lew McCoy
With all due respect, that can be bad advice. By changing it, he might have
made it "work" much better.
I've "worked out pretty well" with 2 watts. He also may have been
radiating 2 watts, even though his rig was producing 100.
So let me modestly propose Lewallen's Suggestion: If you change it, it
might work a whole lot better.
I have a real problem with dismissing established theory with a wave of the
hand. If something works much better, or worse, than the theory predicts, I
really want to know why. What's your explanation of why the kid's dipole
worked so well it wouldn't be benefit from changing?
Roy Lewallen, W7EL
Jeffrey Herman
>I think I am the culprit behind this thread. Without repeating myself, I
>am in ISRAEL. Great place if you want kosher food etc, lousy place if
>you want ladder line. There are no amateur radio stores, no Radio
>Shacks, etc. I can get all the 75 ohm TV coax I want. All the short
>towers, narrowband TV yagi's, etc.
>
>Things like ladder line, 300 ohm twinlead, insulators, BALUNS, MFJ (or
>any other brand) tuners, transceivers (require a permit), etc must be
>ordered from the US or Europe. Once they get here, I have to take off
>time from work to go argue with the meches (import tax) people to get it
>out of hock.
>Geoff.
Why not make twin-lead out of two lengths of 75 ohm coax? Tie the
outer shields together at each end; the shields at the transmitter
end go to ground. The two center conductors make up your twin-lead.
The two lengths of coax can be any distance apart. The outer shields
at the antenna end aren't connected to anything except each other.
(Can't recall where I saw this - has anyone tried it?)
73 from Hawaii, Jeff KH2PZ