A G5RV is really an inefficient collinear antenna, so it needs to be a
flatop, not a Vee or L. Model it and you will see it is a 'long' (on 20
meters) Extended Double Zepp. The extra length improves the pattern into
multiple lobes at the cost of some gain. A true EDZ has more gain, but only
one very narrow broadside lobe off each side. The G5RV has 3 lobes off each
side.


"W5GT" wrote in message
...
I've had poor luck even using the G5RV as an inverter V.

Dave - W5GT

"Frank" wrote in message
news:iXIMe.184795$9A2.66584@edtnps89...
"News Xtra" wrote in message
...
Guy. My best option is to install a G5VR but having one half bend back
90
degrees horizontally so that when you look down from the top it is L
shaped.
My question is, will this degrade performance very much and in what
way.
Many thanks and regards,
John ZL2TTM

Need more information: How high is the antenna, what type of
transmission
line do you plan on using, and what frequencies will it be used on?

Bending the antenna will reduce the real part of the input impedance,
thus
increasing transmission line losses. It will also tend to increase its
directivity in the direction of the "vee".

The G5RV antenna tends to exhibit higher transmission line losses. See
the
extensive analysis at www.vk1od.net

Suggest you obtain the free download of EZNEC from www.eznec.com then you
can analyze the antenna for yourself. Also there are many free programs
available for transmission line analysis. Probably Reg (G4FGQ) has one
for
free.

Regards,

Frank (VE6CB)

Jim Leder wrote:
A G5RV is really an inefficient collinear antenna, so it needs to be a
flatop, not a Vee or L. Model it and you will see it is a 'long' (on 20
meters) Extended Double Zepp.

Jim, your statement is a little confusing. I know you mean that the
G5RV is 1/4WL too long to be called an Extended Double Zepp on 20m.
An EDZ is a single frequency antenna. The 102' G5RV is an EDZ on 11.5
MHz. EDZ length = 1170/F. And, you're right, G5RV's perform better as
a flat-top.

My modified G5RV performs as well as my 130' doublet fed with ladder-
line, given the slightly different radiation patterns. I vary the
length of the G5RV series matching section as follows:

3.8 MHz 23 ft., 7.2 MHz 35 ft., 10.125 MHz 20 ft., 14.2 Mhz 29 ft.,
18.14 Mhz 36 ft., 21.3 MHz 27 ft., 24.95 MHz 29 ft., 28.4 Mhz 22.5 ft.
--
73, Cecil http://www.qsl.net/w5dxp

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Cecil, no argument. All I meant was the theory behind a G5RV is the same as
an EDZ. Nothing more. The G5RV provides a better pattern than an EDZ at the
expense of some gain, but basically the design criteria is the same. The
original G5RV was never intended to be anything but a 20 meter antenna (at
least as far as I've read). The fact that it works on other bands is just
icing. I use a 'modified' G5RV, similar to what Cebik describes on one of
his web pages (think it's the ZS6BKV design) and found it to be a better
G5RV than the original and it's shorter. Think mine is around 94 feet long.
I've also built a 20 meter EDZ (still have it rolled up in the garage) and
found it to be a great antenna but the beamwidth was too narrow to live
with. BTW, for what ever reason it worked really well on 15 also. My 94'
antenna works well on 40,20,17,12 and part of 10. It will load on 75, but
not sure how well it radiates. SWR on the other 5 bands is under 2.5:1 at
resonance with 40 and 20 under 2:1.
Holy cow, I would never argue with you guys. I guess my main point is that
all of these type of antennas are collinear type antennas and to get the
best performance from them, they need to be in a flat top configuration.
However, you work with what you have and if that dictates a Vee or L
configuration, then you do it.

73's

Jim


"Cecil Moore" wrote in message
...
Jim Leder wrote:
A G5RV is really an inefficient collinear antenna, so it needs to be a
flatop, not a Vee or L. Model it and you will see it is a 'long' (on 20
meters) Extended Double Zepp.

Jim, your statement is a little confusing. I know you mean that the
G5RV is 1/4WL too long to be called an Extended Double Zepp on 20m.
An EDZ is a single frequency antenna. The 102' G5RV is an EDZ on 11.5
MHz. EDZ length = 1170/F. And, you're right, G5RV's perform better as
a flat-top.

My modified G5RV performs as well as my 130' doublet fed with ladder-
line, given the slightly different radiation patterns. I vary the
length of the G5RV series matching section as follows:

3.8 MHz 23 ft., 7.2 MHz 35 ft., 10.125 MHz 20 ft., 14.2 Mhz 29 ft.,
18.14 Mhz 36 ft., 21.3 MHz 27 ft., 24.95 MHz 29 ft., 28.4 Mhz 22.5 ft.
--
73, Cecil http://www.qsl.net/w5dxp

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Jim Leder wrote:
Holy cow, I would never argue with you guys.

Hi Jim, I was just expanding a bit on what you said,
not arguing with you. Please feel free to argue with
me anytime you think I am wrong. I only learn something
new when I'm wrong. And I won't "ploink" you for
disagreeing with me.
--
73, Cecil, http://www.qsl.net/w5dxp


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"Jim Leder" wrote
Holy cow, I would never argue with you guys.

====================================

Yes, its a complete waste of bandwidth.

You, the questioner, can't possibly win. Its never been known to
happen.

They will deliberatly twist and distort anything you say. Then, they
will deliberately twist and distort anything they have said
themselves.

One or two of them, never Cecil, will resort to blackening your
character and, quite unjustifiable, accuse you of lying.

But, on the whole, they are only nice ordinary human beings. It's just
a matter of sorting the wheat from the chaff. ;o)
----
Reg.