Chuck W. wrote:
I understand that strictly speaking a G5RV isn't a multi-band antenna,
but my primary use of it is on 20 meters where it works pretty well as
a 3/2 half-wavelength doublet. It's up about 55 feet now as a flat-top
and I've been working plenty of DX with only about 300-400 watts out.

Never satisfied, and always wanting improvement (it's a compulsion!),
I'm wondering whether a half-square like the Windom HSQ listed here
would be an improvement on 20 meters:
http://www.antennasmore.com/windomhq.htm

I've read that at 20 meters and above, there is more benefit to being
horizontally-polarized at a decent height, so maybe I'm better off with
the G5RV?

Thanks for any thoughts.

Chuck
KB5GC


Hi Chuck,

Cebik conclueds the following when speaking of the Half Square antenna.

" Installing SCVs too high, especially half squares, can easily defeat
the main functional advantage of the antennas. Designing them for 20
meters is a marginal enterprise, and above 20 meters, other antenna
types will normally out-perform the SCVs. The SCVs do come into their
own again until the VHF region, where they can be mounted many
wavelengths above ground and their largely vertical polarization
combined with a beamwidth around 60 degrees may be superior in some
applications to Yagis turned on their side.

Except for these very general comments, I have avoided comparisons with
other types of antennas. Although a thorough comparison would be useful,
the amount of material there is to present on SCVs and the shortage of
space within which to present it suggests that this must be (as they
sometimes say in textbooks) "an exercise left to the reader." --Cebik.

you can read the whole article at :

http://www.cebik.com/scv/scv4.html

My best guest is that at 55 feet the G5RV is a better all round antenna
on 20 Meters.

73 Dave Kc1di

Thanks, Dave! It's always a temptation to fiddle with things, but end
up changing them for the worse. I'll leave well enough alone for now!

-Chuck

Okay, so here's a slightly-off-subject follow-up. I looked thru
cebik's web site and didn't see this addressed: Since the G5RV isn't
particularly resonant on 17 and 15 meters, if I connected a dipole for
each of these bands, in parallel, at the same feedpoint as the G5RV
would this work effectively?

Way back when, I recall putting multiple dipoles at the same feedpoint
without incident, but I haven't really seen this discussed much.
Intuition suggests that they would interact negatively and impedance
would be wacky.

-Chuck

Chuck W. wrote:
Okay, so here's a slightly-off-subject follow-up. I looked thru
cebik's web site and didn't see this addressed: Since the G5RV isn't
particularly resonant on 17 and 15 meters, if I connected a dipole for
each of these bands, in parallel, at the same feedpoint as the G5RV
would this work effectively?

That's what antenna modeling programs are good at. There
would probably be some interaction on the higher bands.
--
73, Cecil, http://www.qsl.net/w5dxp

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"Chuck W." wrote in message
oups.com...
Okay, so here's a slightly-off-subject follow-up. I looked thru
cebik's web site and didn't see this addressed: Since the G5RV isn't
particularly resonant on 17 and 15 meters, if I connected a dipole for
each of these bands, in parallel, at the same feedpoint as the G5RV
would this work effectively?

I had dipoles cut for 40, 17, and 12 m all in parallel, and it works fine,
so long as you can get several feet of separation between the ends of the
dipoles and the other wires. Just tune the highest frequency antenna first
and then work down. This was for a 50 Ohm feedline. A real G5RV uses 1/2
wavelength at 20 m of 450 Ohm line; this is transparent at 20 m, but makes
the antenna usable on 80. The 450 Ohm line would probably mess up any
parallel dipoles you hang across the G5RV.

Tam/WB2TT

Way back when, I recall putting multiple dipoles at the same feedpoint
without incident, but I haven't really seen this discussed much.
Intuition suggests that they would interact negatively and impedance
would be wacky.

-Chuck

Just tune the highest frequency antenna first
and then work down..........

It's much easier if you start low, and go up...
If you have interaction, it's almost always a
"higher" band. So if you start low, you'll only
have to do each, once...Going the other way,
can have you chasing your tail after a while...
IE: the higher bands will usually change when
adding the lower bands if the wires couple...
Rarely the case, the other way around.
I've used parallel dipoles for years...
My favorite config for everyday use dipoles.
Once, even had paralleled turnstiles for 80/40 on
one coax...
At the present, I have 160/80/40 on one coax..
To make a noticable difference over a dipole,
you'll need to get some serious gain...If you don't
get at least 4-5 db over the dipole, I hardly think it's
worth the hassle...That G5RV would have appx 2-3
db broadside over a 1/2 dipole, assuming you aren't
losing power feeding it... I agree with Reg, I'd either
run coax, or ladder line, but not both....To me , running
both is an exercise in sillyness...But to many, their own...
Ladder line, if you have a tuner, or coax, if single band,
or a remote tuner, etc...

..................................................
Is it true, though, that when the ladderline/windowline gets wet it
negatively impacts the efficiency of the transmission line?
.................................................. ...

Depends on the ladder line, and whats in between the wires...
300 ohm line can be bad, and also other lines that have no
"windows", etc between the wires...Supposably, the "windowed"
ladder line is less effected by rain. Open ladder line with insulators,

almost no impact at all...I've seen 300 ohm line turn near useless
on UHF when raining hard. I used it to a large UHF TV antenna I
used to receive ATV. Great when dry, but get it wet.....
MK

wrote in message
oups.com...
Just tune the highest frequency antenna first
and then work down..........
..............................
You are right, of course . I got mixed up. Thanks for pointing it out.

Tam/WB2TT