Bob Wood wrote:

Thanks again Mark,

I am currently located in South Central New Mexico and all of the stations
on the net are East and North East of my location. Since FB ratio is not a
concern for me I think your suggestion of an Extended Double Zepp (EDZ)
would work just fine. 0.64 wave on a side would work perfectly since the
0.75 wave per side that I had been considering was really pushing the size
of my back yard. I will have to look into the EDZ but am assuming that the
max radiation pattern would be broadside to the wire which would work
perfectly for me.

Yes. Appx 5.1 dbi in two directions broadside to the wires. Or almost
exactly 3 db over the 1/2 wave dipole.

North-South which would provide the East-West broadside radiation and if it
has any gain over a dipole, I will be ahead for sure. I know that I do not
have enough room on the property to install two elements so I think we will
now shoot for the EDZ and see how it works.

Should do pretty well. Will be appx 84 ft a side. Get it as high as you
can, and preferably set up as a flat top. It will work as as inv vee,
but the gain may drop off a bit. I ran one on 20m one time, and it did
well. One thing about the 40m EDZ.. If you feed with ladder line and a
tuner, it can be used on other bands also. Even 80m should work ok,
being it's longer than a 80m 1/2 dipole. Always use the minimum
inductance needed to get a usable match when tuning the tuner. MK
--
http://web.wt.net/~nm5k

Bob

If you are still uncertain about what angle to use for a V with 1/4 waves
per side, you might get alot of insite from how good LPV antennas are
designed. The basic idea used for the LPV depends on the pattern from each
side of the V to combine to provide good directivity at that frequency where
the elements are 3/4 wave long.

Jerry



"Bob Wood" wrote in message
...
V Beam antenna question

I want to put up a 40M V Beam antenna to enhance communication in one
direction only. From the limited design information that I have found, I
am
thinking of 3/4 wavelength on each side with a horizontal separation angle
of either 72 degrees or 120 degrees. I have seen both separation angles
listed as optimum for maximum gain. I was wondering if anyone knew for
sure
which angle would produce the best result. Also, and actually most
important, I need to have some idea of what the feed point impedance might
be. I can feed it with ladder line or good coax and a balun but I am not
sure what balun to use or would it be better to use ladder line? I sure
would appreciate any guidance on this antenna project.

Bob
W5QCP

Bob

If you are still uncertain about what angle to use for a V with 1/4 waves
per side, you might get alot of insite from how good LPV antennas are
designed. The basic idea used for the LPV depends on the pattern from each
side of the V to combine to provide good directivity at that frequency where
the elements are 3/4 wave long.

Jerry



"Bob Wood" wrote in message
...
V Beam antenna question

I want to put up a 40M V Beam antenna to enhance communication in one
direction only. From the limited design information that I have found, I
am
thinking of 3/4 wavelength on each side with a horizontal separation angle
of either 72 degrees or 120 degrees. I have seen both separation angles
listed as optimum for maximum gain. I was wondering if anyone knew for
sure
which angle would produce the best result. Also, and actually most
important, I need to have some idea of what the feed point impedance might
be. I can feed it with ladder line or good coax and a balun but I am not
sure what balun to use or would it be better to use ladder line? I sure
would appreciate any guidance on this antenna project.

Bob
W5QCP

Bob Wood wrote:
"I want to put up a 40M V Beam antenna to enhance communication in one
direction only.---I am thinking of 3/4 wavelength on a side with a
horizontal separation angle of either 72 degrees or 120 fegrees."

Arnold B. Bailey catalogs a bidirectional horizontal unterminated Vee in
"TV and Other Receiving Antennas" Ends of the Vee must be terminated in
their surge impedance for unidirectional response. Bailey gives 800 ohms
as surge impedance of the wires in the Vee.

All antennas in Bailey`s catalog are "optimized" for a frequency of 200
MHz (1.5 meters).

The horizontal Vee is center-fed at its apex. So, it opens / closes
toward its best directions, since It is unterminated. It is
bidirectional.

Bailey`s Vee is several wavelengths per side. Its drivepoint resistance
is 160 ohms. Gain is 10 dB. 3-dB bandwidth is 3%. It still behaves as a
standing wave antenna without termination.

The Vee is made from two horizontal 35-foot #10 wires for 200 MHz,
forming an included angle of 35-degrees (21-feet between outer ends).

At 40m, the wavelength is about 27 times that at 1.5m. So, that`s the
scale factor. The wires become about 933 feet long.

The same wire formed into a rhombic is unidirectional if terminated. It
only takes one termination resistor, and the rhombic gives 3 or 4 more
dB gain than the same wires in a Vee. The rhombic is a little shorter
overall than the Vee, too. At 40 meters the rhombic requires about 567
feet overall length and is about half as wide as it is long.

If you can accept a total gain of about only 4 dB, you can have an
antenna with much less wire and space. Two parallel center-fed wires,
each about 1/2-wavelength, and 1/4-wave apart, elevated at about
1/2-wavelength, and connected together with parallel open-wire line in
the plane of the wires will give a drivepoint resistance of near 50 ohms
across either antenna.

Which direction is favored depends on which dipole is fed directly and
which acts as the directly connected reflector. 3 dB bandwidth is 60%,
which is much better than the 3% of the unterminated Vee.

Arnold B. Bailey gives data on page 521 of "TV and Other Receiving
Antennas" for the "Half-Wave Antenna and Connected Reflector". He
credits P.S. Carter, Proc. I.R.E.,vol. 20, p1032, June 1932.

Best regards, Richard Harrison, KB5WZI

Bob Wood wrote:
"I want to put up a 40M V Beam antenna to enhance communication in one
direction only.---I am thinking of 3/4 wavelength on a side with a
horizontal separation angle of either 72 degrees or 120 fegrees."

Arnold B. Bailey catalogs a bidirectional horizontal unterminated Vee in
"TV and Other Receiving Antennas" Ends of the Vee must be terminated in
their surge impedance for unidirectional response. Bailey gives 800 ohms
as surge impedance of the wires in the Vee.

All antennas in Bailey`s catalog are "optimized" for a frequency of 200
MHz (1.5 meters).

The horizontal Vee is center-fed at its apex. So, it opens / closes
toward its best directions, since It is unterminated. It is
bidirectional.

Bailey`s Vee is several wavelengths per side. Its drivepoint resistance
is 160 ohms. Gain is 10 dB. 3-dB bandwidth is 3%. It still behaves as a
standing wave antenna without termination.

The Vee is made from two horizontal 35-foot #10 wires for 200 MHz,
forming an included angle of 35-degrees (21-feet between outer ends).

At 40m, the wavelength is about 27 times that at 1.5m. So, that`s the
scale factor. The wires become about 933 feet long.

The same wire formed into a rhombic is unidirectional if terminated. It
only takes one termination resistor, and the rhombic gives 3 or 4 more
dB gain than the same wires in a Vee. The rhombic is a little shorter
overall than the Vee, too. At 40 meters the rhombic requires about 567
feet overall length and is about half as wide as it is long.

If you can accept a total gain of about only 4 dB, you can have an
antenna with much less wire and space. Two parallel center-fed wires,
each about 1/2-wavelength, and 1/4-wave apart, elevated at about
1/2-wavelength, and connected together with parallel open-wire line in
the plane of the wires will give a drivepoint resistance of near 50 ohms
across either antenna.

Which direction is favored depends on which dipole is fed directly and
which acts as the directly connected reflector. 3 dB bandwidth is 60%,
which is much better than the 3% of the unterminated Vee.

Arnold B. Bailey gives data on page 521 of "TV and Other Receiving
Antennas" for the "Half-Wave Antenna and Connected Reflector". He
credits P.S. Carter, Proc. I.R.E.,vol. 20, p1032, June 1932.

Best regards, Richard Harrison, KB5WZI

I want to thank all that replied to my request for information on the 40M
V-Beam. I certainly learned a tremendous amount of new things to consider
and to try. I did not realize that a V-Beam was numerous wavelengths and
that fact alone precludes the installation of such for my current residence.
I believe that I will try a better, higher, high quality dipole and then
experiment with a horizontal loop and perhaps a phased horizontal array if I
can squeeze these within the property lines.

Thanks again to all who shared their time and ideas with me and others
monitoring this thread.

Bob Wood
W5QCP
Alamogordo, NM

I want to thank all that replied to my request for information on the 40M
V-Beam. I certainly learned a tremendous amount of new things to consider
and to try. I did not realize that a V-Beam was numerous wavelengths and
that fact alone precludes the installation of such for my current residence.
I believe that I will try a better, higher, high quality dipole and then
experiment with a horizontal loop and perhaps a phased horizontal array if I
can squeeze these within the property lines.

Thanks again to all who shared their time and ideas with me and others
monitoring this thread.

Bob Wood
W5QCP
Alamogordo, NM