The pattern and gain will be different on every band.
Where the antenna acts as a long wire, maximum gain
will be in the lobes closest to the wire, typically 25 to 35
degrees each side of the wire depending on length and frequency.
Here is an empirical analysis I wrote on the subject in 1997.
There might be 2 dB gain at the center of the peak lobe
on the high bands. Less on the lower bands. Some
descriptions imply vertical radiation from the 2 wire
transmission line. Don't believe it.
Tom N4KG
The G5RV is a 100 foot center fed wire antenna.
Think of it as a long wire for each band and look up the patterns
for each length in the ARRL Antenna Book or other source.
80M .35 WL "short" dipole figure 8 pattern broadside to wire
40M .70 WL "long" dipole figure 8 pattern broadside to wire
30M 2X .5 WL Two Half waves in phase - figure 8 pattern 50 degrees
wide
broadside to wire
20M 3/2 WL current fed LW - 6 lobes - 4main lobes approx 35* to wire
2 minor lobes broadside to wire
17M 2X 1 WL voltage fed LW's - 4 lobes approx 40* to wire
15M 2X 1.1 WL voltage fed LW's - 4 major lobes, possible minor
(this is my "intuitive analysis...check w/modeling program)
12M 5/2 WL current fed LW - 10 lobes - 4 main lobes approx 30* from
wire
10M 2X 3/2 WL voltage fed LW - 6 lobes - 4 main lobes approx 35* to
wire
2 minor lobes broadside to wire
de Tom N4KG 11 / 26 / 97
On Mon, 9 Jul 2001 larry fields <n6hpx_du3@yahoo.com> writes:
> Last march,while I was operating from Manila,as DU1,
> I was using 2 G5RV's,and they worked pretty good..
> My question is what<if any> is the DB gain on these
> antennas,I have never seen any recent reviews on
> em..the antennas are the 100 foot and 50 foot
> models,and the 100 ft. was operated at 51 feet above
> the ground..
> Thanks,Larry,n6hpx/du1
>
> p.s. I am thinking of using a M2loop for 6 meters,next
> time I return there in January..whats a opinion on this..
>
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
List Sponsor: Are you thinking about installing a tower this summer? Call us
for information on our fabulous Trylon Titan self-supporting towers - up to
96-feet for less than $2000! at 888-833-3104 <A
HREF="http://www.ChampionRadio.com";>
www.ChampionRadio.com</A>
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|