"Mark Keith" wrote in message
om...
"Dave VanHorn" wrote in message
...
"Mark Keith" wrote in message
om...
George Cronk wrote in message
. 154.205...
Does anyone know where I can get plans for this antenna? Materials
needed
to build one?

Thanks

You would be better off with a 1/4 wave ground plane on 2m. Seriously.
And one of those can be as simple as five 19 inch pieces of wire and a
So-239 connector. MK

Why would he be better off with a 1/4 wave, with it's large vertical
lobe?

Cuz it's easier decoupled with it's 1/4 wave radials, and is less
likely to have feedline radiation than the funky 5/8 antenna with 1/4
wave radials. In direct comparisons here, the 1/4 GP was a good bit
better than the 5/8 with 1/4 radials.

Interesting. You obviously have developed a far superior measurement
technique than most antenna engineering firms, and maybe even NIST. Your
results disagree with pretty much everyone who measures antenna gain
professionally, and the ARRL handbooks, but hey they must all be wrong then.

Though it's entirely done in the HF spectrum, a pretty detailed analysis is
presented he
http://www.cebik.com/58-3.html
A good ground, and cleaner near-field space, is easier to come by at VHF and
UHF, so I would expect results to be somewhat better than what was seen here
even at the high end of the HF spectrum.

If you google a bit, you'll probably find some articles on converting a CB
antenna to a 5/8 2 meter antenna.

Dave VanHorn wrote,
lobe?

Cuz it's easier decoupled with it's 1/4 wave radials, and is less
likely to have feedline radiation than the funky 5/8 antenna with 1/4
wave radials. In direct comparisons here, the 1/4 GP was a good bit
better than the 5/8 with 1/4 radials.

Interesting. You obviously have developed a far superior measurement
technique than most antenna engineering firms, and maybe even NIST. Your
results disagree with pretty much everyone who measures antenna gain
professionally, and the ARRL handbooks, but hey they must all be wrong then.

Though it's entirely done in the HF spectrum, a pretty detailed analysis is
presented he
http://www.cebik.com/58-3.html
A good ground, and cleaner near-field space, is easier to come by at VHF and
UHF, so I would expect results to be somewhat better than what was seen here
even at the high end of the HF spectrum.

If you google a bit, you'll probably find some articles on converting a CB
antenna to a 5/8 2 meter antenna.


In volume 1 of the Antenna Compendium series is an article entitled "The
5/8-Wavelength Antenna Mystique" by Donald K. Reynolds, K7DBA.
I don't think Reynolds would disagree with Mark too much.
73,
Tom Donaly, KA6RUH

"Dave VanHorn" wrote in message

Cuz it's easier decoupled with it's 1/4 wave radials, and is less
likely to have feedline radiation than the funky 5/8 antenna with 1/4
wave radials. In direct comparisons here, the 1/4 GP was a good bit
better than the 5/8 with 1/4 radials.

Interesting. You obviously have developed a far superior measurement
technique than most antenna engineering firms, and maybe even NIST.

Maybe so if using a simple antenna switch to A/B test is superior...

Your
results disagree with pretty much everyone who measures antenna gain
professionally, and the ARRL handbooks, but hey they must all be wrong then.

No, they do NOT disagree with most who have a clue. BTW, those
"results" I gave you with gain numbers were from modeling.

Though it's entirely done in the HF spectrum, a pretty detailed analysis is
presented he

HF? Thats the problem....You can't apply the performance shown on HF,
and expect it to pan out on 2m. The decoupling problem will rear it's
head on VHF.

http://www.cebik.com/58-3.html
A good ground, and cleaner near-field space, is easier to come by at VHF and
UHF, so I would expect results to be somewhat better than what was seen here
even at the high end of the HF spectrum.

A good ground is not the whole answer. Decoupling is more important at
those higher frequencies.

If you google a bit, you'll probably find some articles on converting a CB
antenna to a 5/8 2 meter antenna.

Why would I need to do that? I already done that before. I've built
enough 5/8 antennas to choke a horse. Maybe two or three. Thats why
I'm fairly comfortable with what I say.
I'd like to ask one question. Have you ever actually compared the two
types at the same time using a switch? MK

"Dave VanHorn" wrote in message

If you google a bit, you'll probably find some articles on converting a CB
antenna to a 5/8 2 meter antenna.

One note...There is only one case on VHF where I often prefer a 5/8
over a 1/4 , and that is on a car when roof mounted. The 5/8 will
usually "picket fence" less, if you are in an area that is all flat
terrain. But as far as elevated ground planes at the house, I prefer
the 1/4 wave anyday. If I use 5/8 elements at home, it will always be
a dual 5/8 collinear of some type. Not a GP with 1/4 wave radials. MK

"Dave VanHorn" wrote in message

Though it's entirely done in the HF spectrum, a pretty detailed analysis is
presented he
http://www.cebik.com/58-3.html
A good ground, and cleaner near-field space, is easier to come by at VHF and
UHF, so I would expect results to be somewhat better than what was seen here
even at the high end of the HF spectrum.

It's more decoupling than anything. Although the usual 5/8 GP with 1/4
wave radials is a flawed animal from the git-go. I think the best
article to describe the effect is from a Dr. Reynolds , "I think thats
the name anyway", that wrote an article for AEA about this problem.
They put out a small brochure with the article and some pictures. They
described the problems with most of the common verticals used. IE: 1/2
waves, 5/8's, and collinears. The result of all that led to the
development of the AEA isopole. Probably the best decoupled dual 5/8
collinear ever designed. And thus , the highest performing compared to
less well decoupled competitors. Thats why cushcraft modified their
ringo ranger, and added a decoupling section, and renamed it the ringo
ranger 2. The effects of a lack of decoupling was glaring when
compared to an antenna of the same appx size, using good decoupling.
The RR was also an appx dual 5/8, although slightly perverted in
dimensions...The RR2 is a good antenna. But the isopole will still
usually beat it. The 5/8 GP or other poorly decoupled antenna does
have the rare chance of the feedline currents adding in phase and
creating some gain, but this is like a one in twenty chance...Like
going to Vegas...Doesn't usually work out that way for most people.
Never did for me...I've never had an elevated 5/8 GP on 2m that was
worth a hoot. Not a one...
Only on a car were they ok. But you look at a car...It's large enough
to usually provide a lower 5/8's of sorts, and also there is no
feedline radiation to skew the pattern upwards. The feedline radiation
if any, is shielded by the car body.
HF is a whole different story. On 10m, a 5/8 GP is best over both a
1/4 wave and a 1/2 wave. I've tested this many times in the real
world...
HF is less critical as far as using a real low wave angle, and also
the average angle used , even locally, is probably slightly higher.
But it doesn't apply to VHF or UHF. It's a whole different world
there, and feedline decoupling is by far the most critical part of a
good antenna. Not brute gain numbers. It won't do any good if the gain
is not where you need it. And thats under 5 degrees for local VHF. MK

Looking over the replies to this post makes me wonder where the helpful
ham hand is lurking these days. This poor guy just wants to know about
plans and materials for an antenna to build and all but one reply tells
him he doesn't want one or you should buy this one or he's stupid for
considering one or I can get into this repeater with that antenna, bla,
bla bla. It can be made with the same components as an SO-239 1/4 wave
ground plane but with a little more wire with a cork screw turn at the
bottom. Doesn't anyone have the simple plans for this guy?

George Cronk wrote:

Does anyone know where I can get plans for this antenna? Materials needed
to build one?

Thanks

On Mon, 05 Apr 2004 00:54:06 GMT, Mike wrote:

Looking over the replies to this post makes me wonder where the helpful
ham hand is lurking these days. This poor guy just wants to know about
plans and materials for an antenna to build and all but one reply tells
him he doesn't want one or you should buy this one or he's stupid for
considering one or I can get into this repeater with that antenna, bla,
bla bla. It can be made with the same components as an SO-239 1/4 wave
ground plane but with a little more wire with a cork screw turn at the
bottom. Doesn't anyone have the simple plans for this guy?

George Cronk wrote:

Does anyone know where I can get plans for this antenna? Materials needed
to build one?

Thanks
Actually I do have plans for a colinear 5/8 over 5/8 2 meter antenna;
all you'd have to do is omit the phasing coil and top radiator. This
one is built from wire on an SO-239.

To the original poster - I can scan the sketch & email it to you, let
me know if you'd like that & it's a done deal.

Howard
KE6something or other

Mike wrote in message .com...
Looking over the replies to this post makes me wonder where the helpful
ham hand is lurking these days. This poor guy just wants to know about
plans and materials for an antenna to build and all but one reply tells
him he doesn't want one or you should buy this one or he's stupid for
considering one or I can get into this repeater with that antenna, bla,
bla bla. It can be made with the same components as an SO-239 1/4 wave
ground plane but with a little more wire with a cork screw turn at the
bottom. Doesn't anyone have the simple plans for this guy?

Sure, if he really wants to use an inferior antenna, I can tell him
how to build it. It's simple. A 5/8 wave radiator, and about 4-5 turns
of coil on a one inch form for matching will get him fairly close.
But I don't recommend one. You wouldn't get me running a 5/8 GP on 2m
for anything. It's like G5RV's on 80m...They usually suck...So do most
5/8's GP's on 2m...:/ But don't take my word for it. Compare them with
an antenna switch and see. The only time I ever see a 5/8's beat a 1/4
on 2m, is if they are nearly on the ground. And I think thats just a
line of sight deal... MK

Hustler makes a 5/8 wave 2M antenna they call the SF-2. HRO sells them for
$14.95.
At that price the only reason to make one is "for fun" but that's
worthwhile.
73, K3DWW

"George Cronk" wrote in message
54.205...
Does anyone know where I can get plans for this antenna? Materials needed
to build one?

Thanks