G5RV vs. Half Square on 20m
 

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

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:
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 (over the G5RV) on 20 meters:
http://www.antennasmore.com/windomhq.htm

Suggest you obtain a copy of EZNEC (free demo available at
www.eznec.com) and observe the radiation patterns. In a
nutshell, the G5RV will outperform the HSQ in four directions.
The HSQ will outperform the G5RV on 20m in the directions of
the G5RV pattern nulls on 20m because the HSQ distributes the
RF energy differently. From their web page, the HSQ radiation
pattern looks more like a vertical on 20m. So the answer is:
In some directions, you will be disappointed with the HSQ. In
other directions, you will be satisfied with the HSQ. I
personally don't see how you would ever be satisfied with
the price of the HSQ. :-)
--
73, Cecil, http://www.qsl.net/w5dxp

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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

The performance of a G5RV as a multi-band dipole, because of its
length of coax feedline, is somewhat worse than any other random
length of dipole fed with a random length of feedline of random
impedance.

Remove the coax, bring the feedline all the way back to the shack, and
the G5RV is just as good as any other simple multi-band,
multi-directional antenna.

As with other random length antennas a tuner is always useful.
----
Reg. G4FGQ.

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

On 25 Apr 2005 16:54:36 -0700, "Chuck W." wrote:

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

That's true, SWR increases, but how much do you want to operate when
it is raining?

bob
k5qwg