[Premium-Rx] B&W Antenna

Wed May 4 12:38:11 EDT 2011

I had a Racal Antennas copy of the B&W Wideband Dipole. It worked really 
well on receive but was no match for my simple inverted-V on transmit.
I eventually sold it to a military vehicle enthusiast who was also a Novice 
Ham. The first thing he did was break the 12:1 balun, so I repaired it for 
him.
He found that the the 'swamping' resistor was cracked and managed to get the 
company who made it to send him a replacement. However I never
heard anymore from him. I suspect the was of the impression that because it 
was a Racal piece, that it would be a dream antenna.

Ian, GM0UHC

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Subject: Premium-Rx Digest, Vol 54, Issue 3

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Today's Topics:

   1. B&W Antenna for sale (machine.age at comcast.net)
   2. am interseted in your antenna (billbeamon at comcast.net)
   3. B&W Antenna SOLD (machine.age at comcast.net)
   4. Re: B&W Antenna for sale (George Georgevits)
   5. Re: B&W Antenna for sale (Bob Kulow)
   6. Re: B&W Antenna for sale (Terry O')
   7. Re: B&W Antenna for sale (Robert Nickels)
   8. Re: B&W Antenna for sale (Williams, Barry)
   9. Re: B&W Antenna for sale (Thomas Adams)
  10. Re: B&W Antenna for sale (Bob Betts)

----------------------------------------------------------------------

Message: 1
Date: Tue, 3 May 2011 18:22:43 +0000 (UTC)
From: machine.age at comcast.net
Subject: [Premium-Rx] B&W Antenna for sale
To: Premium-Rx at mailman.qth.net
Message-ID:
<709812996.817210.1304446963171.JavaMail.root at sz0159a.emeryville.ca.mail.comcast.net>

Content-Type: text/plain; charset=utf-8

Gents

I am finally getting around to selling my Barker & Williamson folded 
dipole---their part number BWD-90. Commercial/military quality folded 
dipole.

See at their website http://www.bwantennas.com/ama/fdipole.ama.htm

Retails for $325.00. Had up for a year in Denver, so no corrosion.

Sell to group for $75.00 plus shipping.

Thanks to all. This is it for me, off the air.

John England

San Jose, CA

------------------------------

Message: 2
Date: Tue, 3 May 2011 19:38:08 +0000 (UTC)
From: billbeamon at comcast.net
Subject: [Premium-Rx] am interseted in your antenna
To: Premium-Rx at mailman.qth.net
Message-ID:
<1174452761.4811759.1304451488363.JavaMail.root at sz0044a.emeryville.ca.mail.comcast.net>

Content-Type: text/plain; charset=utf-8

"I am finally getting around to selling my Barker & Williamson folded 
dipole---their part number BWD-90. Commercial/military quality folded 
dipole."

Pls contact KD4FNC, billbeamon -at- comcast.net

------------------------------

Message: 3
Date: Tue, 3 May 2011 20:39:19 +0000 (UTC)
From: machine.age at comcast.net
Subject: [Premium-Rx] B&W Antenna SOLD
To: premium-rx <premium-rx at mailman.qth.net>
Message-ID:
<687558876.826024.1304455159894.JavaMail.root at sz0159a.emeryville.ca.mail.comcast.net>

Content-Type: text/plain; charset=utf-8

Gents

I could have sold several. Have 4 guys in line. Number 1 is mailing me a 
check locally.

If falls through, will contact next chap.

Thanks to all.

John England

------------------------------

Message: 4
Date: Wed, 4 May 2011 09:15:30 +1000
From: "George Georgevits" <georgg at bigpond.net.au>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: "Premium Rx" <premium-rx at mailman.qth.net>
Message-ID: <GHEEJEBEIOBJEFDFJIHGKEFNDKAA.georgg at bigpond.net.au>
Content-Type: text/plain; charset="us-ascii"

Hi John,

I am sorry to see anyone go off the air.

Just a quick question if I may? I had a look at your link to the
manufacturer for this antenna. I don't want to buy it (sorry), its just that
when simple antennas make what seem like extraordinary claims, it tends to
arouse my curiosity!

That little item in the centre of the dipole at the top - that wouldn't
happen to be a rather large resistor would it?

Also, did you ever happen to compare the performance of this antenna to that
of a straight tuned dipole? Just wondering if there was much difference.

Cheers,
George Georgevits
Sydney, Oz

VK2KGG

> -----Original Message-----
> From: premium-rx-bounces at mailman.qth.net
> [mailto:premium-rx-bounces at mailman.qth.net]On Behalf Of
> machine.age at comcast.net
> Sent: Wednesday, 4 May 2011 4:23 AM
> To: Premium-Rx at mailman.qth.net
> Subject: [Premium-Rx] B&W Antenna for sale
>
>
> Gents
>
>
> I am finally getting around to selling my Barker & Williamson
> folded dipole---their part number BWD-90. Commercial/military
> quality folded dipole.
>
>
> See at their website http://www.bwantennas.com/ama/fdipole.ama.htm
>
>
> Retails for $325.00. Had up for a year in Denver, so no corrosion.
>
>
> Sell to group for $75.00 plus shipping.
>
>
> Thanks to all. This is it for me, off the air.
>
>
> John England
>
>
> San Jose, CA
> ______________________________________________________________
> Premium-Rx mailing list
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> Help Contact eMail:  paul at 8zo.com
> Home Page:  http://www.premium-rx.org/

------------------------------

Message: 5
Date: Tue, 03 May 2011 21:39:24 -0400
From: Bob Kulow <edison1946 at gmail.com>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: premium-rx at mailman.qth.net
Message-ID: <4DC0AE4C.6030604 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I had one of those antennas years ago.  I was glad when a tree fell down
on it and destroyed it!

Yes, the big round thing is a resistor.  The antenna is broadbanded and
works equally poorly between 3 and 30 MHz.  It can be useful for net
operations where there is no competition for the frequency.  Otherwise,
a random wire and a tuner works a*lot* better.

73
Bob WA2UEH

------------------------------

Message: 6
Date: Tue, 03 May 2011 21:29:52 -0500
From: Terry O' <watkins-johnson at terryo.org>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: premium-rx at mailman.qth.net
Message-ID: <4DC0BA20.4020503 at terryo.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

It's just a T2FD antenna.  Tons of info on the internet on how to make
them.  Basically just broadening the bandwidth by lowering the Q with a
swamping resistor.

I've strung a couple together over the years.  They are adequate,
especially for receiving on HF where the high atmospheric noise masks
the lost antenna gain.  If fact the T2FD sounds like it works better
than other antennas because it is quieter due to its built-in signal
attenuation.  This is misleading to many folks.

But transmitting into an antenna effectively paralleled with a dummy
load is a pretty inefficient way to do things.  No way I'd ever pay
someone for one for that use.

Terry O'
http://watkins-johnson.terryo

------------------------------

Message: 7
Date: Tue, 03 May 2011 22:19:19 -0500
From: Robert Nickels <ranickel at comcast.net>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: premium-rx at mailman.qth.net
Message-ID: <4DC0C5B7.9050601 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 5/3/2011 8:39 PM, Bob Kulow wrote:
>   It can be useful for net operations where there is no competition for 
> the frequency
They also use 'em for ALE (Automatic Link Establishment) mode, where the
radio has to switch frequencies quickly to find the best propagation.
That's why they're often seen on government buildings, etc.   I would
think the automatic antenna tuners would be a much better option.

73, Bob W9RAN

------------------------------

Message: 8
Date: Tue, 3 May 2011 22:39:09 -0500
From: "Williams, Barry" <Barry.Williams at nov.com>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: "'W9RAN at oneradio.net'" <W9RAN at oneradio.net>,
"'premium-rx at mailman.qth.net'" <premium-rx at mailman.qth.net>
Message-ID:
<184545B9C095D0469F8555AA820D9B3E24421B5243 at Srvhouexc04.nov.com>
Content-Type: text/plain; charset="iso-8859-1"

One of the fellows who had to go out and set up radio systems at embassies 
pointed out that in some places there may be radio operators who know little 
about the antenna systems.  This type antenna is not optimum, but works 
without power fold back on all frequencies, so is basically trouble free and 
worked well enough.

73,
Barry
KD5VC
------Original Message------
From: Robert Nickels
To: premium-rx at mailman.qth.net
ReplyTo: W9RAN at oneradio.net
Subject: Re: [Premium-Rx] B&W Antenna for sale
Sent: May 3, 2011 10:19 PM

On 5/3/2011 8:39 PM, Bob Kulow wrote:
>   It can be useful for net operations where there is no competition for 
> the frequency
They also use 'em for ALE (Automatic Link Establishment) mode, where the
radio has to switch frequencies quickly to find the best propagation.
That's why they're often seen on government buildings, etc.   I would
think the automatic antenna tuners would be a much better option.

73, Bob W9RAN
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------------------------------

Message: 9
Date: Wed, 04 May 2011 01:45:51 -0600
From: Thomas Adams <quixote2 at ix.netcom.com>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: "George Georgevits" <georgg at bigpond.net.au>, "Premium Rx"
<premium-rx at mailman.qth.net>
Message-ID: <E1QHVtW-0007hD-Tk at elasmtp-junco.atl.sa.earthlink.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 17:15 03-05-11, George Georgevits wrote:

>That little item in the centre of the dipole at the top - that wouldn't
>happen to be a rather large resistor would it?
>
>Also, did you ever happen to compare the performance of this antenna to 
>that
>of a straight tuned dipole? Just wondering if there was much difference.
>
>Cheers,
>George Georgevits
>Sydney, Oz
>
>VK2KGG

Yep...   the center housing contains a resistor and a balun. The B&W
antenna is a rather
badly designed T2FD, combined with some rather shaky marketing claims.

I'm a bit of a T2FD buff here, and for me the B&W specs are a joke.

Sure, a T2FD design may well show a low VSWR over 1.8 - 30 MHz, or an
even WIDER
range...  but once you exceed perhaps 4 octaves, as you go higher in
frequency the
radiation pattern with ANY T2FD variant turns into garbage; a ton of
high angle minor
lobes, and NO major lobes to speak of.

Here, I cover HF with TWO T2FDs; the low one is cut to cover 1.750 -
7.0 MHz, and the high
one goes 7.0 - 28 MHz.

To those who argue that the T2FD is nothing more than a dummy load
because of the resistor;
the argument tells me a number of things about them.

The first is that they've never actually USED a T2FD. It's an
effective antenna, if used intelligently.

The second thing is that they haven't figured out that EVERY antenna
design is a trade-off. Sure,
some of your transmitter power just heats up the resistor... but
you're trading off radiation
efficiency at discreet frequencies for reasonable performance across
wide bandwidths.

To get BOTH on HF, the only design I know of that will do it is a
discone. Anybody got a 100 foot
tower and maybe a half mile of #12 wire laying around?  'Cause that's
what it would take to erect
one...   not to mention a sizable chunk of real estate.

Well...   lemme get off of my soapbox.

Mr. T.   W9LBB

------------------------------

Message: 10
Date: Wed, 4 May 2011 06:55:29 -0700 (PDT)
From: Bob Betts <rwbetts at sbcglobal.net>
Subject: Re: [Premium-Rx] B&W Antenna for sale
To: premium-rx at mailman.qth.net
Message-ID: <250248.51158.qm at web83608.mail.sp1.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

Hello Group:
This topic was covered in great detail on the yahoo antenna group and some 
of that info may bear repeating here.
The B&W folded dipole is actually a T2FD that was developed more than a 
half-century ago. As a product of the cold war, it went into countless 
installations at embassies around the world. B&W has enjoyed one of the 
longest contract arrangements ever,?with the US military and government 
agencies, as well. Like any engineering design effort, there is always a 
compromise between quality, quantity, and cost. A racing car gets bad 
mileage; and a "green" car shouldn't be on the race track. The same applies 
to the T2FD.
Its low gain, and on some bands, bad gain, is a trade off for loading 
flatness over a very large range of bands. These antennas are (and have 
been)?the defacto HF antenna for TOC (Tactical Operations Center), War Room 
Comms, LP's (Listening Posts), and (especially) embassy roof tops. I have 
installed dozens of them here and in Vietnam?in the military and later for 
"other"?customers and know exactly what to expect from them when compared to 
band-specific antennas. But the performance loss is a real advantage for the 
"clerk-operated" stations where SWR and tuning could be a real problem. In 
the Signal Corps, we were doing a lot of frequency hopping and the T2FD was 
virtually always employed. An interesting observation is that when used for 
intercept or surveillance, one of the pre/postselectors was usually 
used,?due to the broadband characteristics of the antenna -- this was 
especially true of the early solid state?radios where the equipment
had?inadequate front end filtering.
?
Bob

http://www.bobsamerica.com
* Music *?Audio *?Radio *
"It's all good"

------------------------------

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