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Old May 16th 04, 10:36 PM
John Smith
 
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Default How good or bad is the B&W antannas?

Gernic antenna, if it is within 3:1 vswr then it is matched fairly well.
Gain is directional, this one should have a pattern that changes as one
moves up in frequency, more lobes.
good one to check on on EZNEC (demo free on internet)
Low Freq need a good ground.
Also this type of antenna was used in the 20's and 30's, and on the ships at
sea.

"R. David Steele" /OMEGA wrote in message
...
http://www.bwantennas.com/

The military is using these antennas because of ALE (automatic
linking) and NVIS. I gather that while they are very broad
banded, they have less the best gain?

Any feed back?



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Old May 16th 04, 11:10 PM
Bob Miller
 
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On Sun, 16 May 2004 21:13:58 GMT, R. David Steele
/OMEGA wrote:

http://www.bwantennas.com/

The military is using these antennas because of ALE (automatic
linking) and NVIS. I gather that while they are very broad
banded, they have less the best gain?

Any feed back?


According to a QST review about 20 years ago, the B&Ws are comparable
to a standard dipole from 20 meters and up; much less efficient than a
standard dipole, below 20 meters.

bob
k5qwg


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Old May 16th 04, 11:49 PM
JGBOYLES
 
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According to a QST review about 20 years ago, the B&Ws are comparable
to a standard dipole from 20 meters and up; much less efficient than a
standard dipole, below 20 meters.


Yep, a short 80m antenna does ok on 20m. The Military, in their quest to get a
signal out, in the smallest space possible devised a scheme that used a very
inefficient antenna. From what I have read, it was a 20 kw transmitter with
matching auto-tuner that tuned from 2-30 mhz.
One makes up for the -6db loss on 4mhz with brute force. The B&W has 6db or
more loss on 80m. As a ham, I hope my antenna is very efficient. When I am
mobile that is not possible, but fixed, I want an efficient antenna.


73 Gary N4AST
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Old May 17th 04, 03:00 AM
'Doc
 
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David,
The bottom line is that it's a terrible 'amateur' antenna for
the price.
'Doc
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Old May 17th 04, 04:02 AM
Jack Twilley
 
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-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

"Doc" == w5lz writes:


[... David mentioned B&W antennas ...]

Doc David, The bottom line is that it's a terrible 'amateur' antenna
Doc for the price. 'Doc

Out of curiosity, what other antenna provides a better cost-benefit
ratio while maintaining the same constraints with respect to power,
size, and construction?

Jack.
- --
Jack Twilley
jmt at twilley dot org
http colon slash slash www dot twilley dot org slash tilde jmt slash
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Old May 17th 04, 12:57 PM
'Doc
 
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David,
You're at least partially right, I don't have the
slightest idea of what 'ALE' is (although I do have
an idea). As a previous owner of one of the subject
antennas, I also have a pretty good idea of it's
worth to the average amateur.
'Doc
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Old May 17th 04, 01:00 PM
'Doc
 
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Jack Twilley wrote:

Out of curiosity, what other antenna provides a better cost-benefit
ratio while maintaining the same constraints with respect to power,
size, and construction?

Jack.


Jack,
Almost anything! The only 'one' who benefits from this
antenna's
'cost-benefit' is the manufacturor...
'Doc
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Old May 17th 04, 03:51 PM
Jack Painter
 
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"R. David Steele" wrote about the B&W design:

Remember that the military does two things. One is NVIS which
has the antenna mounted about 1/4 wavelength above ground. This
gives a good ground effect from 2 MHz to 12 MHz out to 300 miles.

The other is ALE, automatic link, which switches frequencies
automatically to insure the best path. An antenna with tuner
would just be too slow.


David, even for purposes of this discussion, that is a bit oversimplified.
Perhaps that type of broadband temporary antenna installation is acceptable
for field units, but have never seen one of them in a permanent
installation. I happen to be around several hundred HF antenna
installations, and neither NVIS nor ALE operating units use anything of the
kind. Maybe you were referring to field units, as above, not sure. Also,
ATU/couplers are always used for ALE systems, with the memory-response times
measured in milliseconds. This applies to air, ground and marine units for
all armed services. There is no magic antenna for all bands ALE, and units
using NVIS would have little need for ALE in the first place. That doesn't
mean the military hasn't wasted money on it somewhere for short range use,
it just wouldn't realize it's potential for reliable medium to long range
linking.

Jack Painter
Virginia Beach, Va


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Old May 17th 04, 06:00 PM
Mike Coslo
 
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Jack Twilley wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


"Doc" == w5lz writes:


[... David mentioned B&W antennas ...]

Doc David, The bottom line is that it's a terrible 'amateur' antenna
Doc for the price. 'Doc

Out of curiosity, what other antenna provides a better cost-benefit
ratio while maintaining the same constraints with respect to power,
size, and construction?



Hmmm, How about an Isotron? 8^) Man, there is a small antenna!

If you take the bands that the B&W performs adequately on, the size
ratio between it an a halfwave dipole isn't quite so good. I suppose the
FD that is most comparable to my antenna is the BWD 90. It's 90 feet, as
we might figure. My dipole is 96 feet.

My dipole cost less than 30 dollars to make. If you count the tuner, I
still spent less money.

- Mike KB3EIA -


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Old May 17th 04, 06:00 PM
David G. Nagel
 
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'Doc wrote:

Jack Twilley wrote:

Out of curiosity, what other antenna provides a better cost-benefit
ratio while maintaining the same constraints with respect to power,
size, and construction?

Jack.



Jack,
Almost anything! The only 'one' who benefits from this
antenna's
'cost-benefit' is the manufacturor...
'Doc

Doc

Having used a B&W antenna for several years all I can say is that it
does the job I ask of it. It provides me with a frequency agile antenna
that allows me to change frequency quickly without having a mess of wire
hanging from the trees in my yard.
Yes it is not the most efficient of sky hooks but it does what I need it
to do.
You obviously don't need these abilities. More power to you but please
do not dismiss the B&W out of hand without considering the requirements
of those that do. When someone asks about the B&W just give the facts
about the antenna and not your personal opinion.

Dave WD9BDZ

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