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Old August 19th 05, 04:54 PM
Jim Leder
 
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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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