Sine the G5RV is designed for 20 meters, and is a compromise on the
other bands: I conclude that the 1/2 scale G5RV is a 10 meter antenna;
and is a compromise on the other bands!

Old Ed wrote:
Uhhhh, Reg...

Don't look now, but:

1. The equations underlying the Smith Chart don't become more
valid when they are programmed into a computer.

2. Antennas scale with frequency, as you are undoubtedly aware.
So a half-size antenna used at twice the frequency is neither
more nor less "ridiculous" than the "full-sized" version.

3. The "not bad" matches Cecil was talking about were/are
achieved WITHOUT the use of an outboard antenna tuner.
So our hypothetical G5RV/2 DX chaser just might bag the
quarry while you are still getting your tuner on frequency.

Ed

"Reg Edwards" wrote in message
...

The ancient Smith chart may tell somebody about something.

But I'm still laughing about the ridiculous half-size G5RV. And so,
in his grave, is Mr Varney.

Anything will work after a fashion at one frequency. It's so easy to
find one. But by which time the DX has faded away.
----
Reg, G4FGQ

Hi there, Op...

Well, the devil is in the details, isn't it?

One "compromise" from a Mercedes is a Yugo.
That would be a pretty big come-down.

But another "compromise" from a Mercedes would be a BMW
(or vice-versa). That wouldn't be hard to take at all.

Presumably, the reference antennas against which the G5RV is
called a "compromise" are full-sized dipoles for the respective
bands. IF the G5RV can come reasonably close to those
(and many users seem to think it can), then there is a pretty
good basis for its enduring popularity.

73, Ed

"Ham op" wrote in message
...
Sine the G5RV is designed for 20 meters, and is a compromise on the
other bands: I conclude that the 1/2 scale G5RV is a 10 meter antenna;
and is a compromise on the other bands!

The full size G5RV IS A 20 Meter antenna!! That's a fact.

It performs as designed on 20 meters!!

Any wire can be made to radiate on other frequencies by using stubs,
baluns, tuners, etc. But that does not change the fact that the G5RV is
designed as a 20 meter antenna!!

It works on other harmonically related bands, but it is still a 20 meter
design!

I used one about 6 years ago. Then changed to a center fed doublet with
open wire tuned feeders. I'll take the doublet/tuned feeders any day!

Ham Op


Old Ed wrote:

Hi there, Op...

Well, the devil is in the details, isn't it?

One "compromise" from a Mercedes is a Yugo.
That would be a pretty big come-down.

But another "compromise" from a Mercedes would be a BMW
(or vice-versa). That wouldn't be hard to take at all.

Presumably, the reference antennas against which the G5RV is
called a "compromise" are full-sized dipoles for the respective
bands. IF the G5RV can come reasonably close to those
(and many users seem to think it can), then there is a pretty
good basis for its enduring popularity.

73, Ed

"Ham op" wrote in message
...

Sine the G5RV is designed for 20 meters, and is a compromise on the
other bands: I conclude that the 1/2 scale G5RV is a 10 meter antenna;
and is a compromise on the other bands!

Hi again, Ham Op -

You're one step ahead of me re the G5RV in that you have
used one. I have not. I see no reason to doubt your (inferred)
statement that you were only satisfied with it on 20m.

However, the ARRL antenna book lists the G5RV in the chapter
on Multiband Antennas, and begins the description as follows:
"A multiband antenna that does not require a lot of space, is simple
to construct, and is low in cost is the G5RV." (To be fair, the ARRL
piece goes on to state that 20m is the most-favored band in the
G5RV design.)

A common-sense question would be: Why would Varney design
a single-band 20m doublet that is bigger and more complicated
than a single-band 20m dipole, unless he was looking for some
added benefit--e.g., multiband operation? Alas, I don't have ready
access to Varney's old articles, so his thought process will have to
remain unknown to me for the time being.

I have no wish to assume the role of Chief Defender of the G5RV.
I merely responded to some G5RV/2 criticisms that I found illogical.
My dipoles are of the trap and fan variety, and I like them that way.

If I go off the reservation to another type of wire antenna, it won't
be either a Windom or a G5RV; I'd like to experiment with a
multiresonant OCF design. (I really don't want to bring antenna
tuners into my mix--either the conventional lumped-constant type,
or Cecil's variable-line-length type.) I like "instant" QSY+QRO.
Your mileage may vary.

Good DX,

Anonymous Handle (just for grins)

"Ham op" wrote in message
...
The full size G5RV IS A 20 Meter antenna!! That's a fact.

It performs as designed on 20 meters!!

Any wire can be made to radiate on other frequencies by using stubs,
baluns, tuners, etc. But that does not change the fact that the G5RV is
designed as a 20 meter antenna!!

It works on other harmonically related bands, but it is still a 20 meter
design!

I used one about 6 years ago. Then changed to a center fed doublet with
open wire tuned feeders. I'll take the doublet/tuned feeders any day!

Ham Op

"Old Ed" wrote
A common-sense question would be: Why would Varney design
a single-band 20m doublet that is bigger and more complicated
than a single-band 20m dipole, unless he was looking for some
added benefit--e.g., multiband operation?

The reason Varney used a G5RV in preference to an ordinary dipole was
because of its clover-leaf radiation pattern on 20 metres. He is quite
clear about this. He could work Europe and N.America from S.America
without changing antennas. Otherwise, for 20 metres, he would have
chosen the better antenna - an ordinary halfwave dipole which also
can be used multiband over an openwire line, the line being
conveniently of any length.

The reason the G5RV became popular with amateurs was because of its
theoretical attraction when Varney published it. The ideas of
cloverleaf and 1/2-wavelength feedline, combined in one simple system,
were quite clever, easy to understand and therefore intellectually
attractive. Also, 20 metres happens to be the best all-year-round,
day and night, DX band.

And so began the bandwagon. With a little forced imagination on the
part of dealers, multi-band operation (on which it is weak) soon
followed.

Even its name, The Famous G5RV, sounds very nice. If Louis Varney had
had a call like BF6POX nobody would ever have heard of it.
----
Reg.

Reg Edwards wrote:
The reason the G5RV became popular with amateurs was because of its
theoretical attraction when Varney published it. The ideas of
cloverleaf and 1/2-wavelength feedline, combined in one simple system,
were quite clever, easy to understand and therefore intellectually
attractive. Also, 20 metres happens to be the best all-year-round,
day and night, DX band.

If Varney didn't intend to use the antenna on 80m and 40m, why
didn't he just feed it with coax? 1/2WL of twinlead doesn't change
the feedpoint impedance on 20m but it does wonders on 80m and 40m.
--
73, Cecil http://www.qsl.net/w5dxp

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Cec sed,
" If Varney didn't intend to use the antenna on 80m and 40m, why
didn't he just feed it with coax?
=================================

He was averse to feeding a balance antenna over an unbalanced line.
Went against the grain.

Coax was rarely used in his day and age anyway. Too heavy and
expensive.

Everything was open wire. Home made. Couldn't buy it.

Transmitters had tuned tanks and link coupling to openwire line.

And he didn't like RF in the shack. Or radiation from the feedline.
TV's used 45 MHz - the 3rd harmonic of 20 metres.

But most likely, it didn't occur to him.
----
Reg.

"Old Ed" wrote
Presumably, the reference antennas against which the G5RV is
called a "compromise" are full-sized dipoles for the respective
bands. IF the G5RV can come reasonably close to those
(and many users seem to think it can),

==============================
Can 250,000 housewives be wrong?
Of course they can!

Reg Edwards wrote:

"Old Ed" wrote
Presumably, the reference antennas against which the G5RV is
called a "compromise" are full-sized dipoles for the respective
bands. IF the G5RV can come reasonably close to those
(and many users seem to think it can),

Can 250,000 housewives be wrong?
Of course they can!

Reg, I just modeled the half-sized G5RV using EZNEC.
The dipole is 3/2WL on 10m and the twinlead is 1/2WL
on 10m. EZNEC reports the following 50 ohm SWRs at
the twinlead/coax junction.

10m - 2.0:1, 20m - 2.7:1, 40m - 2.6:11

I would be hard pressed to tell the difference between
the efficiency of a half-sized G5RV vs a resonant
dipole for those three bands.
--
73, Cecil, http://www.qsl.net/w5dxp

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----