Sgordon wrote:
Considering putting up a Vee Beam for 17 meters. I then ran across a couple
websites that show a multiband Vee Beam cut for 15 tuning it for 6-20m. Has
anyone built even a mono-band Vee Beam? How did it preform?
If you would cut one for say 40 meters and feed with opern wire, how will it
preform on the higherbands? Just really looking for some more info on them.

There's a fair amount of info on V-antennas in the 15th edition of The ARRL
Antenna Book including sloping terminated V's.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

"Sgordon" wrote in message gy.com...
Considering putting up a Vee Beam for 17 meters. I then ran across a couple
websites that show a multiband Vee Beam cut for 15 tuning it for 6-20m. Has
anyone built even a mono-band Vee Beam? How did it preform?
If you would cut one for say 40 meters and feed with opern wire, how will it
preform on the higherbands? Just really looking for some more info on them.

Vee beams, being basically half a rhombic, are not really cut to any
one frequency.
The only real consideration as to length, is to the amount of gain you
will get.
That will vary on the length of the wires per wavelength of the
frequency being used at the time. You can use one on any band, if it's
long enough to qualify as a true vee beam, but you would design the
length for the amount of gain you want on the lowest band to be used.
One wave per leg would be the minimum, and that's not much of a vee
beam. Most are multi waves per leg. Feeding with a tuner and open wire
line as you suggest will be fine, and is the usual method used. The
higher the freq, the higher the gain in general. The angle between the
wires needs to be considered though. In general, the longer the
antenna in wavelengths, the smaller the angle between the wires for
optimum results. MK

I passed along this info to Dean Straw, N6BV, the ARRL Antenna Book
editor. He replied that since the 19th Edition, he's used EZNEC/4 (an
NEC-4 based program) for generating rhombic and vee beam data. I'd hope
that it would agree closely with the 1980 NEC analysis.

Roy Lewallen, W7EL

Crazy George wrote:
Scott:

The curves for V Beams in the ARRL Antenna Handbook, and apparently also in
the engineering texts were derived from a few experimentally determined data
points assuming a sinusoidal current on the arms. In the July 1980 IEEE
Transactions on Antennas and Propagation, Gary Thiele and Ernie Ekelman
published a rigorous NEC analysis of the configuration, including a couple
of useful curves. Both the optimum included angle vs. arm length and
directivity vs. arm length differ significantly from the previously
published curves. So, dig up a copy of IEEE-A&P Trans., Vol. AP-28, No. 4,
and look on pp. 588-590 for the full story.

--
Crazy George
Remove NO and SPAM from return address

Roy, this brings up a question , and am curious about-- Just what are the
differences between EZNEC and EZNEC -4 ? Have had copies of Elnec, thru
EZNEC, and you keep doing great job improveing each one, but keep hearing
about NEC-4 (as opposed to NEC, and NEC-2), and am curious (no puns
intended), as to what are the major advantages of NEC-4 over NEC, and NEC-2
(what ever happened to NEC-3?) Is it worth upgradeing to, or, of interest
only to someone doing complex arrays ? I'm sure others would also be
interested, as am not in a position to get engineering tomes (am retired),
but am curious. Kinda like a teacher that was at Oregon Institute of
Technology (last name of "Barber"), who ran a company that built antennas
for military planes - turned out a curtain, so if part of hull was shot, the
rest of the hull would radiate! Wished I had more oppurtunity when still in
K.Falls to pump him, but they cut his teaching position. Guess you the
expert to ask, now-- Jim NN7K




"Roy Lewallen" wrote in message
...
I passed along this info to Dean Straw, N6BV, the ARRL Antenna Book
editor. He replied that since the 19th Edition, he's used EZNEC/4 (an
NEC-4 based program) for generating rhombic and vee beam data. I'd hope
that it would agree closely with the 1980 NEC analysis.

Roy Lewallen, W7EL

Crazy George wrote:
Scott:

The curves for V Beams in the ARRL Antenna Handbook, and apparently also
in
the engineering texts were derived from a few experimentally determined
data
points assuming a sinusoidal current on the arms. In the July 1980 IEEE
Transactions on Antennas and Propagation, Gary Thiele and Ernie Ekelman
published a rigorous NEC analysis of the configuration, including a
couple
of useful curves. Both the optimum included angle vs. arm length and
directivity vs. arm length differ significantly from the previously
published curves. So, dig up a copy of IEEE-A&P Trans., Vol. AP-28, No.
4,
and look on pp. 588-590 for the full story.

--
Crazy George
Remove NO and SPAM from return address

There are two major differences between EZNEC and EZNEC/4. The first is
that EZNEC/4 is one of the two EZNEC pro programs, the other being
EZNEC-M. These programs are intended for professional use (although some
amateurs have bought them) and cost several times as much as the
standard version of EZNEC. The added features of the pro versions are
10,000 segment capability, the ability to read and write description
files in NEC format, ground wave analysis, automated rectangular wire
grid creation, and a way to do advanced replication, rotation, and
translation of groups of wires. EZNEC-M is identical to EZNEC/4 except
that EZNEC-M only has an NEC-2 calculating engine, while EZNEC/4 gives
you the choice of NEC-2 or NEC-4. And the availability of an NEC-4
calculating engine is the second difference between EZNEC and EZNEC/4,
since EZNEC has only NEC-2.

The most striking advantage of NEC-4 over NEC-2 is that it allows the
modeling of buried conductors. It also is relatively free of the error
NEC-2 creates when modeling connected wires of dissimilar diameters, and
will hold up better at the edges of calculation capability. For example,
it'll handle loops which are a bit smaller than the smallest that NEC-2
can manage. For most models above ground, though, NEC-2 and NEC-4 will
give you virtually identical results.

NEC-4 has some additional capabilites which I haven't yet implemented in
EZNEC/4. These include the ability to include the effect of wire
insulation, and the ability to define the conductivity and permittivity
of the primary medium (fixed at free space for NEC-2). It also does some
checking of the geometry for errors such as overlapping or crossing
wires. EZNEC/4 does have it run these checks.

NEC-2 is public domain software -- anyone can get it and use it for any
purpose, free. It's on the Web as both source code and compiled for a
number of platforms. But NEC-4 is copyrighted by the University of
California, and is not free. Any U.S. citizen can buy it for use within
the U.S. I believe the cost is still $850, although there's a discount
for universities, and some military and defense groups can get it free.
I sell EZNEC/4, which includes an NEC-4 calculating engine, only to
people and organizations whom I've confirmed have a valid NEC-4 license,
via confirmation from the issuing agency. (You don't need to have NEC-4
in order to run EZNEC/4, but you must have purchased it before I'll sell
EZNEC/4 to you.) EZNEC/4 is $600 on top of the $850 NEC-4 fee, so no, an
upgrade from EZNEC isn't a viable choice for the vast majority of hobby
users.

NEC-3 was a forerunner of NEC-4, and was sort of a first attempt at
implementing NEC-4's advanced features. It had a number of shortcomings
which were fixed in NEC-4. NEC-4 wasn't available to the public for a
number of years, and NEC-3 was never made available to the public.

If anyone is seriously interested in purchasing NEC-4, drop me an email
and I'll be glad to tell you whom to contact.

Roy Lewallen, W7EL

wrote:
Roy, this brings up a question , and am curious about-- Just what are the
differences between EZNEC and EZNEC -4 ? Have had copies of Elnec, thru
EZNEC, and you keep doing great job improveing each one, but keep hearing
about NEC-4 (as opposed to NEC, and NEC-2), and am curious (no puns
intended), as to what are the major advantages of NEC-4 over NEC, and NEC-2
(what ever happened to NEC-3?) Is it worth upgradeing to, or, of interest
only to someone doing complex arrays ? I'm sure others would also be
interested, as am not in a position to get engineering tomes (am retired),
but am curious. Kinda like a teacher that was at Oregon Institute of
Technology (last name of "Barber"), who ran a company that built antennas
for military planes - turned out a curtain, so if part of hull was shot, the
rest of the hull would radiate! Wished I had more oppurtunity when still in
K.Falls to pump him, but they cut his teaching position. Guess you the
expert to ask, now-- Jim NN7K

Thanks, kept seeing posts about NEC-4, but no explanation. At least answers
my question! --Jim NN7K


"Roy sent:
There are two major differences between EZNEC and EZNEC/4. The first is
that EZNEC/4 is one of the two EZNEC pro programs, the other being
EZNEC-M. These programs are intended for professional use (although some
amateurs have bought them) and cost several times as much as the
standard version of EZNEC. The added features of the pro versions are
10,000 segment capability, the ability to read and write description
files in NEC format, ground wave analysis, automated rectangular wire
grid creation, and a way to do advanced replication, rotation, and
translation of groups of wires. EZNEC-M is identical to EZNEC/4 except
that EZNEC-M only has an NEC-2 calculating engine,