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OT: B & W antenna

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Ken G Kopp

OT: B & W antenna

The B & W antenna was/is a T2FD. I have several rolled up in my shed, and
all National Guard armories in Montana have them in use.

73 - K0PP
On Dec 9, 2015 19:00, "Charlie T, K3ICH" <[hidden email]> wrote:

> I forget the name of it, (MAX-something) but there was an "antenna"
> produced back in the 70's that consisted of a sealed center box with a coax
> connector on the bottom and two eyes to attach dipole wires. The ads
> claimed good match from 80 thru 10 M. It was basically a 50 Ω
> non-inductive resistor across the feed line which also connected to the two
> eyes. It was potted, so you had to destroy it to see what was inside. If
> did in fact radiate a little and of course provided a decent match to the
> coax.
>
> Another "slightly" more efficient antenna was produced by the venerable B
> & W Company and sold as a wide band dipole. It's coax feed point had a
> 6:1 balun which fed a fairly wide (12" ??) spaced 90 foot folded dipole
> which was terminated with a 600 Ω *resistor in the center, physically
> right above the center fed balun. We had one at Microlog and used it quite
> successfully on the HAM bands as well as the Marine SITOR freqs, however, a
> random 100 foot dipole fed directly with coax thru an MN-2700 generally
> worked better.
>
> My point here is that there is a wide range of antenna types & performance
> and they all work to some degree.
>
> Hard to beat a simple resonant dipole though.
>
> I agree with Joe. Nothing wrong with traps either, especially since
> there's no 'tuner' required.
>
> 73, Charlie k3ICH
>
>
>
> * (Might be wrong on the value....seems it should be 300 Ω. Then again,
> maybe the balun was 12:1)
>
>
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k6dgw

Re: OT: B & W antenna

All Guard armories everywhere had/have them since I was a teenager [when
dirt was young]. They served/serve a specific purpose very well, wide
band coverage where nobody is trying to work DX.

We had fan dipoles [2 or 3 freqs] in SE Asia, tough to tune, especially
on missions. Fortunately, when they arrived with our gear, the guys in
the Philippines had already adjusted and marked them.

I wonder sometimes why coupled-resonator dipole haven't caught on in the
ham community. I've built several, the first when the WARC HF bands
opened. They're cheap, easy to build, and extremely easy to adjust, and
they're "a half-wave dipole" on every band with a predictable pattern
and balanced feed. I've never done more than 3 bands, but I've heard in
the past [anecdotally] doing 5 using those old crossed spacers designed
for cage elements.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 12/9/2015 6:10 PM, Ken G Kopp wrote:
> The B & W antenna was/is a T2FD. I have several rolled up in my shed, and
> all National Guard armories in Montana have them in use.
>
> 73 - K0PP

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NK7Z

Re: OT: B & W antenna

The BED-90 works fairly well on 75 Meters, about 2 S units down from a
dipole, but it has a 1:1 on almost any frequency between 3 MHz., and 30
Mhz., which is fine for me as I am using a KW for MARS work, and we are
on clear frequencies...

I have heard several stories about what it has for a resistor on it, if
anyone knows for sure, I would be most interested.
--
Thanks and 73's,
For equipment, and software setups and reviews see:
www.nk7z.net

For MixW support see;
http://groups.yahoo.com/neo/groups/mixw/info
For Dopplergram information see:
http://groups.yahoo.com/neo/groups/dopplergram/info
For MM-SSTV see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Wed, 2015-12-09 at 19:17 -0800, Fred Jensen wrote:

> All Guard armories everywhere had/have them since I was a teenager [when
> dirt was young]. They served/serve a specific purpose very well, wide
> band coverage where nobody is trying to work DX.
>
> We had fan dipoles [2 or 3 freqs] in SE Asia, tough to tune, especially
> on missions. Fortunately, when they arrived with our gear, the guys in
> the Philippines had already adjusted and marked them.
>
> I wonder sometimes why coupled-resonator dipole haven't caught on in the
> ham community. I've built several, the first when the WARC HF bands
> opened. They're cheap, easy to build, and extremely easy to adjust, and
> they're "a half-wave dipole" on every band with a predictable pattern
> and balanced feed. I've never done more than 3 bands, but I've heard in
> the past [anecdotally] doing 5 using those old crossed spacers designed
> for cage elements.
>
> 73,
>
> Fred K6DGW
> - Northern California Contest Club
> - CU in the Cal QSO Party 1-2 Oct 2016
> - www.cqp.org
>
> On 12/9/2015 6:10 PM, Ken G Kopp wrote:
> > The B & W antenna was/is a T2FD. I have several rolled up in my shed, and
> > all National Guard armories in Montana have them in use.
> >
> > 73 - K0PP
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

NK7Z

Re: OT: B & W antenna

Make that BWD-90, not BED-90.
--
Thanks and 73's,
For equipment, and software setups and reviews see:
www.nk7z.net

For MixW support see;
http://groups.yahoo.com/neo/groups/mixw/info
For Dopplergram information see:
http://groups.yahoo.com/neo/groups/dopplergram/info
For MM-SSTV see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Wed, 2015-12-09 at 22:20 -0800, David Cole wrote:
> The BED-90 works fairly well on 75 Meters, about 2 S units down from a
> dipole, but it has a 1:1 on almost any frequency between 3 MHz., and 30
> Mhz., which is fine for me as I am using a KW for MARS work, and we are
> on clear frequencies...
>
> I have heard several stories about what it has for a resistor on it, if
> anyone knows for sure, I would be most interested.

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Barry K3NDM

Re: OT: B & W antenna

In reply to this post by NK7Z

If memory serves, that antenna is a variant of the T2FD and should have
a 490 Ohm resistor in it. As you go higher in frequency, it becomes more
efficient as the resistor will need to absorb less energy; the resistor
is rated at 1/3 the antennas power rating at the low end.

73,
Barry
K3NDM

------ Original Message ------
From: "David Cole" <[hidden email]>
To: [hidden email]
Sent: 12/10/2015 1:20:13 AM
Subject: Re: [Elecraft] OT: B & W antenna

>The BED-90 works fairly well on 75 Meters, about 2 S units down from a
>dipole, but it has a 1:1 on almost any frequency between 3 MHz., and 30
>Mhz., which is fine for me as I am using a KW for MARS work, and we are
>on clear frequencies...
>
>I have heard several stories about what it has for a resistor on it, if
>anyone knows for sure, I would be most interested.
>--
>Thanks and 73's,
>For equipment, and software setups and reviews see:
>www.nk7z.net
>
>For MixW support see;
>http://groups.yahoo.com/neo/groups/mixw/info
>For Dopplergram information see:
>http://groups.yahoo.com/neo/groups/dopplergram/info
>For MM-SSTV see:
>http://groups.yahoo.com/neo/groups/MM-SSTV/info
>
>
>On Wed, 2015-12-09 at 19:17 -0800, Fred Jensen wrote:
>> All Guard armories everywhere had/have them since I was a teenager
>>[when
>> dirt was young]. They served/serve a specific purpose very well,
>>wide
>> band coverage where nobody is trying to work DX.
>>
>> We had fan dipoles [2 or 3 freqs] in SE Asia, tough to tune,
>>especially
>> on missions. Fortunately, when they arrived with our gear, the guys
>>in
>> the Philippines had already adjusted and marked them.
>>
>> I wonder sometimes why coupled-resonator dipole haven't caught on in
>>the
>> ham community. I've built several, the first when the WARC HF bands
>> opened. They're cheap, easy to build, and extremely easy to adjust,
>>and
>> they're "a half-wave dipole" on every band with a predictable pattern
>> and balanced feed. I've never done more than 3 bands, but I've heard
>>in
>> the past [anecdotally] doing 5 using those old crossed spacers
>>designed
>> for cage elements.
>>
>> 73,
>>
>> Fred K6DGW
>> - Northern California Contest Club
>> - CU in the Cal QSO Party 1-2 Oct 2016
>> - www.cqp.org
>>
>> On 12/9/2015 6:10 PM, Ken G Kopp wrote:
>> > The B & W antenna was/is a T2FD. I have several rolled up in my
>>shed, and
>> > all National Guard armories in Montana have them in use.
>> >
>> > 73 - K0PP
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:[hidden email]
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>Message delivered to [hidden email]

Joe Subich, W4TV-4

Re: OT: B & W antenna

In reply to this post by NK7Z

> I have heard several stories about what it has for a resistor on it,
> if anyone knows for sure, I would be most interested.

https://en.wikipedia.org/wiki/T2FD_antenna

73,

... Joe, W4TV

On 12/10/2015 1:20 AM, David Cole wrote:
> The BED-90 works fairly well on 75 Meters, about 2 S units down from a
> dipole, but it has a 1:1 on almost any frequency between 3 MHz., and 30
> Mhz., which is fine for me as I am using a KW for MARS work, and we are
> on clear frequencies...
>
> I have heard several stories about what it has for a resistor on it, if
> anyone knows for sure, I would be most interested.
>
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John Kramer

Re: OT: B & W antenna

I would not touch any antenna that uses a resistor. That is what a dummy load is
after all - great SWR but the losses are huge.

I built a T2FD when I was newly licensed back in 1984 (when I didn’t know any better),
from an article in Practical Wireless. I used the specified resistor and built it according to spec,
and put it on top of a 220 ft building, raised 20 ft above the building. Any antenna
should have worked really well at this height being totally up in the clear. The SWR
was great across all the bands, but I was very disappointed in it’s performance.
I have learnt a lot since then…

BTW nothing wrong with OCFD antennas, they work well on their harmonic
frequencies as a multi band antenna, provided they are installed properly, and a good CMC is used in the
feedline. No, not an ugly Balun which might give you 1000 - 1500 ohms choking impedance
if you’re lucky, but a proper CMC with more than 12 000 ohms choking impedance.

I would rather hang a good OCFD with a quality 4:1 Balun at the feed point, and a
quality CMC choke for 80 - 10 just before the coax enters the house, rather than fiddle with
8 dipoles yuck…

Better yet, would be to use an EFHW 80-10 1K built by www.myantennas.com

73

John, ZS5J

On 10 Dec 2015, at 3:41 PM, Joe Subich, W4TV <[hidden email]> wrote:

> I have heard several stories about what it has for a resistor on it,
> if anyone knows for sure, I would be most interested.

https://en.wikipedia.org/wiki/T2FD_antenna

73,

... Joe, W4TV

On 12/10/2015 1:20 AM, David Cole wrote:
> The BED-90 works fairly well on 75 Meters, about 2 S units down from a
> dipole, but it has a 1:1 on almost any frequency between 3 MHz., and 30
> Mhz., which is fine for me as I am using a KW for MARS work, and we are
> on clear frequencies...
>
> I have heard several stories about what it has for a resistor on it, if
> anyone knows for sure, I would be most interested.
>
______________________________________________________________
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Elecraft mailing list

Re: OT: B & W antenna

In reply to this post by Joe Subich, W4TV-4

It is true! It makes a good antenna that tunes easily it you want to use a QRO transmitter work like a QRP rig with a good antenna. My Dad earned a Novice in the mid seventies at the time that my wife earned an Advanced and I earned an Extra. He called me one evening to report that his club in Denver had an article in the newsletter for an antenna which had a good SWR on all novice bands and worked well. They took a 30 foot aluminum vertical and connected a 75 watt incandescent light bulb between it and ground. I told him that in the mid fifties when I was a Novice we used the same antenna, buy omitted the pole and kept it in the shack, but we called it our dummy load. It glowed brightly with a 75 watt novice transmitter and radiated a little so that we could talk to each other across town with our dummy loads. Any dummy load will radiate a little unless you keep it in a Faraday Cage. Willis 'Cookie' Cooke,VP TARS for 2016 K5EWJ & Trustee N5BPS
From: "Joe Subich, W4TV" <[hidden email]>
To: [hidden email]
Sent: Thursday, December 10, 2015 7:41 AM
Subject: Re: [Elecraft] OT: B & W antenna

> I have heard several stories about what it has for a resistor on it,
> if anyone knows for sure, I would be most interested.

https://en.wikipedia.org/wiki/T2FD_antenna

73,

... Joe, W4TV

On 12/10/2015 1:20 AM, David Cole wrote:
> The BED-90 works fairly well on 75 Meters, about 2 S units down from a
> dipole, but it has a 1:1 on almost any frequency between 3 MHz., and 30
> Mhz., which is fine for me as I am using a KW for MARS work, and we are
> on clear frequencies...
>
> I have heard several stories about what it has for a resistor on it, if
> anyone knows for sure, I would be most interested.
>
______________________________________________________________
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