On 10/29/2012 7:14 AM, W5DXP wrote:
On Sunday, October 28, 2012 6:18:58 PM UTC-5, Channel Jumper wrote:
But your dipole antenna needs to be resonant - 1/2 wavelength on the
lowest frequency you desire to operate on.

Like the G5RV that you dislike, if one removed the feedline from a 1/2WL resonant center-fed dipole, it is no longer resonant. Resonance implies a low resistive feedpoint impedance. The G5RV antenna system has a low resistive impedance looking into the series matching section on 75m, 40m, and 20m (also on 12m).

3/2WL dipole + 1/2WL feedline = resonance on 20m

3/4WL dipole + 1/4WL feedline = resonance on 40m

3/8WL dipole + 1/8WL feedline = resonance on 75m.

The (G5RV) ladder line is the matching network and it only works on 20 meters.

Here's technical proof that it also works on 75m and 40m.

http://www.w5dxp.com/G5RV.HTM

The Smith Chart SWR arc indicates how series section transformers really work. The G5RV is a reasonably good antenna on 75m, 40m, 20m, and 12m. Not so good on 15m and not good at all on 30m, 17m, and 10m. A ZS6BKW is a better choice to obtain 17m and 10m but one loses 75m.

The G5RV antenna system is what it is. It is neither a gift from Heaven nor a design straight from Hell.
--
73, Cecil, w5dxp.com


Unfortunately that is not proof. Proof is when you compare a tuned
dipole on say 75 and a 102 foot G5RV side by side with a switch to a
simple 1/2 wave dipole. Actual testing like this is required.
Mathematics and graphs are simply that, mathematics and graphs. Those
little plots assume that there are no other variables that have not been
considered or even discovered.

Every time I hear a poor signal breaking into our conversation on 75,
and I ask what is their antenna? You guessed it, a G5RV. I always ask
during any qso what antenna they are using and at what power.

No, it is not a design from hell. It is just a poor excuse for a
multi-band antenna. A trapped multi-band dipole will work better from my
experience and I don't like trapped multi-band antennas. The only
antennas that sound weaker on 75 than the G5RV are the random wire
antennas and a vertical using about 4 or 5 buried ground radials. So,
the G5RV is a step up from those horrible antennas.

The G5RV is only gotten popular because it is cheap to buy and easy to
erect. Performance is very difficult for most ham operators to ascertain
because they have nothing with which to compare their G5RV. Many hams
will give someone who is weak a 5/9 reading just to be congenial. They
are not doing the other operators any favours doing this. I always give
my peak s meter readings. This is certainly not a great standard, but is
honest on my part.

So, Cecil, I think you need to erect a simple 75 meter dipole and a coax
switch. See what the other guys says about your two different s meter
readings on 75 meters. This must be done at different time of the day
and night a often. Keep a log of the results.

Michael

On Monday, October 29, 2012 1:48:16 PM UTC-5, Boomer wrote:
So, Cecil, I think you need to erect a simple 75 meter dipole and a coax
switch. See what the other guys says about your two different s meter
readings on 75 meters.

No need for me to do that, Michael, since Tom, W8JI, has already done it and reported the results. He had an A/B switch between a 1/2WL 75m dipole and a G5RV at the same height. He ran two tests:

1. He told the truth about which antenna he was using for the QSO. Most of the hams on the other end of the QSOs agreed that the 1/2WL dipole was superior.

2. He lied about which antenna was which. Most of the hams on the other end of the QSOs agreed that the 1/2WL dipole was superior. But since W8JI lied, they were really agreeing that the G5RV was superior. Were you one of those hams?
--
73, Cecil, w5dxp.com

On 10/29/2012 2:13 PM, W5DXP wrote:
On Monday, October 29, 2012 1:48:16 PM UTC-5, Boomer wrote:
So, Cecil, I think you need to erect a simple 75 meter dipole and a coax
switch. See what the other guys says about your two different s meter
readings on 75 meters.

No need for me to do that, Michael, since Tom, W8JI, has already done it and reported the results. He had an A/B switch between a 1/2WL 75m dipole and a G5RV at the same height. He ran two tests:

1. He told the truth about which antenna he was using for the QSO. Most of the hams on the other end of the QSOs agreed that the 1/2WL dipole was superior.

2. He lied about which antenna was which. Most of the hams on the other end of the QSOs agreed that the 1/2WL dipole was superior. But since W8JI lied, they were really agreeing that the G5RV was superior. Were you one of those hams?
--
73, Cecil, w5dxp.com


No Cecil, I was not. I also would have given my s meter readings
regardless of what I thought it should be. It is important to me to give
my fellow hams as much good data on their antenna work as possible. I
also agree that the hams that are asked about which antenna is sounds
better should not know which antenna they are rating. I have a friend
who has an inverted V dipole at 200 feet and a double bazooka as an
inverted V at 75 feet. He is 100 miles away and the lower antenna is
always the biggest signal. This does not make sense to me, but that is
what is actually happening. The angle of both antennas are the same. We
always need to measure actual performance and not paper performance.

I still think you should do this yourself. Just ABing the receiver is an
important test. G5RVs have a reputation that I cannot personally confirm
of being noisy. I do know for certain that some antennas produce more
noise than others.

My loop does a wonderful job of nulling out the noise from my
neighbour's homes and local industry.

Michael

On Monday, October 29, 2012 2:45:22 PM UTC-5, Boomer wrote:
I still think you should do this yourself. Just ABing the receiver is an
important test. G5RVs have a reputation that I cannot personally confirm
of being noisy. I do know for certain that some antennas produce more
noise than others.

I've spent many years experimenting with G5RVs including field strength measurements vs a dipole and a vertical. When someone has a problem with a G5RV on 75m, it is invariably because good engineering practice was not used in that particular design and installation. An inverted-V at 15 feet with no choke/balun and twinlead taped to a conductive pole and/or laying on the ground is certainly not going to work very well. With both antennas properly designed and installed, it is difficult to tell the difference at resonance on 75m. However, the G5RV is fairly non-functional on 30m, 17m, 15m, and 10m. 17m and 10m are necessities for me and that's why I don't use one. I bought a G5RV in the late 80's expecting it to live up to its all-HF band advertising and I was disappointed. That's when I went to my no-tuner all-HF-band 130' dipole.

http://www.w5dxp.com/notuner.htm

Like any dipole where the two dipole elements are DC isolated from each other, the G5RV is susceptible to precipitation static. An RF choke across the conductors will solve that problem.

On 10/30/2012 8:23 AM, W5DXP wrote:
On Monday, October 29, 2012 2:45:22 PM UTC-5, Boomer wrote:
I still think you should do this yourself. Just ABing the receiver is an
important test. G5RVs have a reputation that I cannot personally confirm
of being noisy. I do know for certain that some antennas produce more
noise than others.

I've spent many years experimenting with G5RVs including field strength measurements vs a dipole and a vertical. When someone has a problem with a G5RV on 75m, it is invariably because good engineering practice was not used in that particular design and installation. An inverted-V at 15 feet with no choke/balun and twinlead taped to a conductive pole and/or laying on the ground is certainly not going to work very well. With both antennas properly designed and installed, it is difficult to tell the difference at resonance on 75m. However, the G5RV is fairly non-functional on 30m, 17m, 15m, and 10m. 17m and 10m are necessities for me and that's why I don't use one. I bought a G5RV in the late 80's expecting it to live up to its all-HF band advertising and I was disappointed. That's when I went to my no-tuner all-HF-band 130' dipole.

http://www.w5dxp.com/notuner.htm

Like any dipole where the two dipole elements are DC isolated from each other, the G5RV is susceptible to precipitation static. An RF choke across the conductors will solve that problem.


Maybe those who chose a G5RV to buy something cheap and easy also then
erect it poorly. I have seen a G5RV erected in my town here. It looks
awful. It works just as well. I talked to another ham a few days ago on
40 meters. His G5RV was mounted at 10 feet. Some guys actually wind
their window line into a coil.

I also saw another antenna in town. It was supposedly a 75 meter zepp.
It had 6 feet of window line and then a 60 of wire wound around a single
tree. I am always amazed at the lack of planning and engineering that go
into some antenna installations.

These guys will never have a good signal and probably never know why.
Most will not ask for help because they already know that their antenna
is great. I don't know why some hams will have their self-esteem tied up
in their rigs and antennas. I mostly use an Icom 751A and I know it is
not the best rig in the world. It is old and needs repair once in a
while. My 75 meter loop at 35 feet of height is not the best antenna in
the world, but it is the best I can do for height given my trees and
property. However, I listened to someone who knew more about antennas
than myself and he convinced me to change my window line feed to open
wire. I got a huge benefit in performance. It does not make sense to me
that a plastic dialectric is so much worse than air. Maybe it is the
change from 450 ohms to 600. But boy did that antenna start working better.

Michael

"Boomer" napisal w wiadomosci
...


My 75 meter loop at 35 feet of height is not the best antenna in the
world, but it is the best I can do for height given my trees and property.
However, I listened to someone who knew more about antennas than myself
and he convinced me to change my window line feed to open wire. I got a
huge benefit in performance. It does not make sense to me that a plastic
dialectric is so much worse than air. Maybe it is the change from 450 ohms
to 600. But boy did that antenna start working better.

The both halves of your antenna work in each cycle as the radiator and next
as the counterpoise.
For the counterpoise the bare wire is better than the insulated.
S*

Szczepan Bialek wrote:

"Boomer" napisal w wiadomosci
...


My 75 meter loop at 35 feet of height is not the best antenna in the
world, but it is the best I can do for height given my trees and property.
However, I listened to someone who knew more about antennas than myself
and he convinced me to change my window line feed to open wire. I got a
huge benefit in performance. It does not make sense to me that a plastic
dialectric is so much worse than air. Maybe it is the change from 450 ohms
to 600. But boy did that antenna start working better.

The both halves of your antenna work in each cycle as the radiator and next
as the counterpoise.

Nope.

For the counterpoise the bare wire is better than the insulated.

Wrong again.

Do you wear slip on shoes?

Hi,
I am blessed to have the DX-CC land in my lap, but used and soon will need
rewiring. Any advice on those coils? Can they just be re-coiled with the
same wire all along? I have a large coil of solid copper wire that is 12g
with the plastic jacket with a uv thin sholack. What are the recemmendations
for the coil turns and lengths of that coil wire?

or am I better off replacing those coils with exactly the same size
enammeled copper wire with two solder joints? Same as the manufacture does.
Would they just do it this way to speed up the process? Make it easier for
mass production?

If I were to wire that top leg all same wire including the coils, is that
preferred? Any ideas as to the specs for doing it that way if you guys think
that is electrically more logical? Or not?

Thanks

73s







"Boomer" wrote in message
...
On 10/30/2012 8:23 AM, W5DXP wrote:
On Monday, October 29, 2012 2:45:22 PM UTC-5, Boomer wrote:
I still think you should do this yourself. Just ABing the receiver is an
important test. G5RVs have a reputation that I cannot personally confirm
of being noisy. I do know for certain that some antennas produce more
noise than others.

I've spent many years experimenting with G5RVs including field strength
measurements vs a dipole and a vertical. When someone has a problem with
a G5RV on 75m, it is invariably because good engineering practice was not
used in that particular design and installation. An inverted-V at 15 feet
with no choke/balun and twinlead taped to a conductive pole and/or laying
on the ground is certainly not going to work very well. With both
antennas properly designed and installed, it is difficult to tell the
difference at resonance on 75m. However, the G5RV is fairly
non-functional on 30m, 17m, 15m, and 10m. 17m and 10m are necessities for
me and that's why I don't use one. I bought a G5RV in the late 80's
expecting it to live up to its all-HF band advertising and I was
disappointed. That's when I went to my no-tuner all-HF-band 130' dipole.

http://www.w5dxp.com/notuner.htm

Like any dipole where the two dipole elements are DC isolated from each
other, the G5RV is susceptible to precipitation static. An RF choke
across the conductors will solve that problem.


Maybe those who chose a G5RV to buy something cheap and easy also then
erect it poorly. I have seen a G5RV erected in my town here. It looks
awful. It works just as well. I talked to another ham a few days ago on 40
meters. His G5RV was mounted at 10 feet. Some guys actually wind their
window line into a coil.

I also saw another antenna in town. It was supposedly a 75 meter zepp. It
had 6 feet of window line and then a 60 of wire wound around a single
tree. I am always amazed at the lack of planning and engineering that go
into some antenna installations.

These guys will never have a good signal and probably never know why. Most
will not ask for help because they already know that their antenna is
great. I don't know why some hams will have their self-esteem tied up in
their rigs and antennas. I mostly use an Icom 751A and I know it is not
the best rig in the world. It is old and needs repair once in a while. My
75 meter loop at 35 feet of height is not the best antenna in the world,
but it is the best I can do for height given my trees and property.
However, I listened to someone who knew more about antennas than myself
and he convinced me to change my window line feed to open wire. I got a
huge benefit in performance. It does not make sense to me that a plastic
dialectric is so much worse than air. Maybe it is the change from 450 ohms
to 600. But boy did that antenna start working better.

Michael

On Thursday, November 1, 2012 6:00:36 PM UTC-5, Tom wrote:
Hi,

I am blessed to have the DX-CC land in my lap, but used and soon will need

rewiring. Any advice on those coils? Can they just be re-coiled with the

same wire all along? I have a large coil of solid copper wire that is 12g

with the plastic jacket with a uv thin sholack. What are the recemmendations

for the coil turns and lengths of that coil wire?



or am I better off replacing those coils with exactly the same size

enammeled copper wire with two solder joints? Same as the manufacture does.

Would they just do it this way to speed up the process? Make it easier for

mass production?



If I were to wire that top leg all same wire including the coils, is that

preferred? Any ideas as to the specs for doing it that way if you guys think

that is electrically more logical? Or not?



Thanks



73s









If it still works, I see no real need to rewire. The green
coating is not going to hurt anything, unless it's so severe
the wire is rotting away. Or if the coating causes a short
between windings for some reason. If not, I would just use
it as is.
But if you really feel compelled to rewire it, I would use
the same exact gauge solid wire that was originally used.
That way you can use the same forms with no design changes.