Ed, this comes from years of practical experience in trying to achieve a
broad antenna.

With all due respect to the various "NEC" programs as well as Reg's program,
they are great for comparing antennas. In the real world environment of most
hams, results do not agree with the predicted on 75.

Why?, because few of us can get a 75 meter antenna any where near a half
wave length high and in the clear. While one may be able to model the real
antenna environment, I am not smart enough. I would suggest that you model
your particular 75 meter antenna, and then measure actual results as a fun
exercise.

Now to the original question, in spite of the data in QST, I have found
spreads of less than 15 feet in a practical environment will not achieve
your goal. YMMV.

We have got to the point in ham radio, we are measuring with a micrometer,
marking with a crayola, and cutting with an axe. I doubt that anyone in the
history of the world has calculated a 75 meter dipole, put it up, and made
no adjustments unless they mis-measured.


Heck for years we have used 468/F to cut our antennas and that is incorrect
as well! Don't rob yourself of the fun of trying something based on a
program. Last night, for example, I had an enjoyable ragchew with a fellow
in England, running my barefoot Icom 706 MKIIG on 75. My antenna is 40 feet
up at it's highest point. Anecdotal evidence for sure, but the QSO was fun
anyway!

Sorry to get so long winded... Good luck on your broad antenna experiments,
the journey is the fun part.

73 Fred W4JLE



"Ed" wrote in message
. 93.175...


Some things that do not work, "the bazooka", dual wires spread less
than 15 feet, and any of the antennas that are terminated folded
dipoles.


Fred, I appreciate your comments on my questions. Could you elaborate
on
your statement (above) that "dual wires spread less than 15 feet" do not
work? The QST article, Table 1, seems to indicate they do work, with a
spread of only 6 feet, or even 3 feet, for 75M dipoles.


Ed K7AAT

Ed wrote:

The May 2005 issue of QST had an interesting antenna article ...

Interesting choice of verb tense, Ed, to describe May 2005. :-)
--
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 =----

Proves the old saying "Even a blind hog finds an acorn sometime."

"Bart Bailey" wrote in message
...
In posted on Sun,
17 Apr 2005 09:24:23 -0400, Fred W4JLE wrote: Begin

I doubt that anyone in the
history of the world has calculated a 75 meter dipole, put it up, and
made
no adjustments unless they mis-measured.

I must be the exception that proves a rule, but back when living in
rural Alabama I measured, cut, and hung mine from pine trees and didn't
have to make any adjustments...
When it blew down during hurricane Fredrick in '79, the replacement,
identical length, never quite matched the original, of course I had to
use different trees, maybe there's a botanical (resin) factor involved?

--

Bart

Fred W4JLE wrote:
I doubt that anyone in the
history of the world has calculated a 75 meter dipole, put it up, and made
no adjustments unless they mis-measured.

I'm one of the hams who calculated a 75 meter dipole, fed it
with ladder-line, and had to make no adjustments. :-)
--
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! 100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---

Nah! Cecil you mis-measured, you can't even get the impedance right. Next
you will be telling me that you change the length of your feed line and
don't need a tuner. :)

"Cecil Moore" wrote in message
...
Fred W4JLE wrote:
I doubt that anyone in the
history of the world has calculated a 75 meter dipole, put it up, and
made
no adjustments unless they mis-measured.

I'm one of the hams who calculated a 75 meter dipole, fed it
with ladder-line, and had to make no adjustments. :-)
--
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! 100,000
Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---

Fred W4JLE wrote:
Nah! Cecil you mis-measured, you can't even get the impedance right.

With a ~50 ohm antenna and ~450 ohm ladder-line,
a match is impossible so why fret about it? :-)
Patient: Doc, it hurts when I do this.
Doc: Then don't do that.
--
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! 100,000 Newsgroups
---= East/West-Coast Server Farms - Total Privacy via Encryption =---

The May 2005 issue of QST had an interesting antenna article ...

Interesting choice of verb tense, Ed, to describe May 2005. :-)


Don't blame me; blame ARRL for coming out so darned early with it!

:^)


Ed

Dear Fred (W4JLE):
Oh my. I never thought of PVC 12" sewer pipe.

Thank you for that, and the other, details. I will be on the lookout
for such pipe and measure its thickness. Apparently, the pipe is strong
enough that the end supports do not buckle. I would have expected to need
supplemental braces on the end supports.

Presumably, the electric fence wire is solid aluminum. If so, you must
use a pair of substantial clamps at the feed point and some sort of Al to Cu
transition.

Thanks. 73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Fred W4JLE" wrote in message
...
They make a 12" PVC pipe. I got some scrap sections from the guy who put
in
sewer lines in my town.

The pipe is cut in such a way that you have rings 12" in diameter and 3/8"
wide. Holes are drilled every 60 degrees. I use 5 rings on each end (10
total). The wires are tied together at the center and end insulators.

I normally tie a wire between a tree and the hitch on my pickup with the 5
rings pre strung. Then add the other 5 wires. Once the whole mess is put
together slide the rings an equal distance apart. The ones at the ends
should be 18 inches from each insulator. Use 6 inch pieces of wire to
anchor
the rings. Wrap a couple of inches around the wire, over the top of the
ring
and continue wrapping on the wire. 3 per ring works well. Being cheap and
as
this antenna uses a LOT of wire I make mine out of electric fence wire
(1/4
mile for $7.00). Get some help holding the ends as you raise it. If not
you
will end up with the worlds biggest "slinky".

"J. Mc Laughlin" wrote in message
...
Dear W4JLE:

Please expand on the paragraph shown below. Sewer pipe is most
often,
hereabout, made of cast iron. What is your pipe made of? How thick is
it?
(I assume that the 3/8" mentioned is the height of pieces of pipe that
were
used as wire spacers.) How many short sections of pipe did you use?

Thanks, Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Fred W4JLE" wrote in message
...
snip

I have used a number of methods over the years to cover 75/80 with a
single
antenna. A 12" diameter cage works well at low heights. I used
sections
of
12 " sewer pipe cut 3/8" thick and 6 wires coming to a cone at the
end.

snip

I think that the reference is to "had" as compared to "has."
73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Ed" wrote in message
. 93.175...



The May 2005 issue of QST had an interesting antenna article ...

Interesting choice of verb tense, Ed, to describe May 2005. :-)


Don't blame me; blame ARRL for coming out so darned early with it!

:^)


Ed

I never used clamps, simply put the 6 wires through the eye of an insulator
and wrap it back on it's self.

The pvc is plenty strong enough, I think the last ones I made the pipe was
almost 1/2" thick outside to inside.

I have used a number of different type wires, one made from enameled copper
wire #18 was neat. You almost could not see the wires at certain times of
day and had the illusion of the rings floating in the air. At another time
of day the sun hit it just right and appeared to be a solid copper pipe
hanging in the air. I have used both Au and galvanized wire and for all
practical purposes they operated the same. The fence wire is #16.

For the connection I normally use brass contacts salvaged from an old
electrical panel. They seem to work well and last a long time.Let me define
my long time, I rarely have an antenna up more than 2 years as I am always
trying something new.


"J. Mc Laughlin" wrote in message
...
Dear Fred (W4JLE):
Oh my. I never thought of PVC 12" sewer pipe.

Thank you for that, and the other, details. I will be on the lookout
for such pipe and measure its thickness. Apparently, the pipe is strong
enough that the end supports do not buckle. I would have expected to need
supplemental braces on the end supports.

Presumably, the electric fence wire is solid aluminum. If so, you
must
use a pair of substantial clamps at the feed point and some sort of Al to
Cu
transition.

Thanks. 73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Fred W4JLE" wrote in message
...
They make a 12" PVC pipe. I got some scrap sections from the guy who put
in
sewer lines in my town.

The pipe is cut in such a way that you have rings 12" in diameter and
3/8"
wide. Holes are drilled every 60 degrees. I use 5 rings on each end (10
total). The wires are tied together at the center and end insulators.

I normally tie a wire between a tree and the hitch on my pickup with the
5
rings pre strung. Then add the other 5 wires. Once the whole mess is put
together slide the rings an equal distance apart. The ones at the ends
should be 18 inches from each insulator. Use 6 inch pieces of wire to
anchor
the rings. Wrap a couple of inches around the wire, over the top of the
ring
and continue wrapping on the wire. 3 per ring works well. Being cheap
and
as
this antenna uses a LOT of wire I make mine out of electric fence wire
(1/4
mile for $7.00). Get some help holding the ends as you raise it. If not
you
will end up with the worlds biggest "slinky".

"J. Mc Laughlin" wrote in message
...
Dear W4JLE:

Please expand on the paragraph shown below. Sewer pipe is most
often,
hereabout, made of cast iron. What is your pipe made of? How thick
is
it?
(I assume that the 3/8" mentioned is the height of pieces of pipe that
were
used as wire spacers.) How many short sections of pipe did you use?

Thanks, Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Fred W4JLE" wrote in message
...
snip

I have used a number of methods over the years to cover 75/80 with a
single
antenna. A 12" diameter cage works well at low heights. I used
sections
of
12 " sewer pipe cut 3/8" thick and 6 wires coming to a cone at the
end.

snip