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. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] 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, W4TVwrote: > 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. > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to jkra...@iafrica.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] OT: B & W antenna
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" <li...@subich.com> To: elecraft@mailman.qth.net 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. > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to wrco...@yahoo.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] 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"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 valueseems it should be 300 Ω. Then again, > maybe the balun was 12:1) > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to kengk...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] 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. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] 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 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
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:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to d...@nk7z.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] OT: B & W antenna
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" <d...@nk7z.net> To: elecraft@mailman.qth.net 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to d...@nk7z.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k3...@comcast.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com