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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? |
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 |
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 |
David, The bottom line is that it's a terrible 'amateur' antenna for the price. 'Doc |
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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 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFAqCs8GPFSfAB/ezgRAs6KAKCrBspPVZNGVycGY8LrSmotdVTjCgCfaKHT gNzRDEBBv0WOb0rRB856QcY= =DG7W -----END PGP SIGNATURE----- |
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 |
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 |
"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 |
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 - |
'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 |
In article Gj4qc.43044$pJ1.24343@lakeread02,
Jack Painter wrote: 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. My wife and I recently spent several weeks touring around Peru (just got back last week). I was intrigued to observe a _lot_ of modest-size HF wire antennas scattered around... and these all appeared to be of this same basic "terminated, folded dipole" variety. I saw a couple at the Cuzco airport, one at a village on the Amazon, one or two in Aguas Calientes (the village right below Machu Picchu), etc. They were usually mounted in an inverted-V configuration, and appeared to be permanent installations rather than short-term field-use installations. The applications were probably NVIS, with working ranges out to a few hundred miles. I can't say for certain that they _were_ T2FDs, as I had no way to go up on the towers and confirm that the device at the center of the upper part of the dipole was a terminating resistor. I've never seen a folded dipole with an open-circuiting insulator at the center of the upper span, though. My guess is that these antennas were chosen because of their "one size fits all" nature - they can be installed and used without trimming, don't require SWR-matching at the transmitter, and their relatively low efficiency may not be an issue in these applications. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
They conform to the manufacturer's specifications.
But the manufacturer's specifications do not mention, at least in numerical terms, the most important parameter - antenna GAIN. The omission can mean only one thing - very poor gain at the lower frequencies. But that is easily corrected by pumping in 10 Kwatts. |
David, Huh! I would have sworn that was just what was asked. 'Doc |
"R. David Steele" wrote in message
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 I never noticed one of them in a permanent (U.S.) 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. 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. 73, Jack Painter Virginia Beach, Va |
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Hash: SHA1 "Mike" == Mike Coslo writes: [... David mentioned B&W antennas ...] Doc David, The bottom line is that it's a terrible 'amateur' antenna Doc for the price. 'Doc Jack Out of curiosity, what other antenna provides a better Jack cost-benefit ratio while maintaining the same constraints with Jack respect to power, size, and construction? Mike Hmmm, How about an Isotron? 8^) Man, there is a small antenna! They're too spooky for me. I don't understand how they work. Mike If you take the bands that the B&W performs adequately on, the Mike size ratio between it an a halfwave dipole isn't quite so Mike good. I suppose the FD that is most comparable to my antenna is Mike the BWD 90. It's 90 feet, as we might figure. My dipole is 96 Mike feet. I guess it depends on what you consider "adequate". If your 96-ft dipole provides comparable SWR matches across all the bands the B&W antennas allegedly provide, that'd be pretty impressive. Like the other poster, I noticed that there were no gain figures in the B&W literature, and that does make me suspicious. Mike My dipole cost less than 30 dollars to make. If you count the Mike tuner, I still spent less money. Sure, so did I. And my antenna was messed up the following spring, due to stretched wire, water leaking into critical bits, and more. If you spent less than thirty dollars and used copperweld or stainless steel, then I'd like to know what trucks that wire falls off so I can chase them around town. Mike - Mike KB3EIA - Jack. - -- Jack Twilley jmt at twilley dot org http colon slash slash www dot twilley dot org slash tilde jmt slash -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFAqZIWGPFSfAB/ezgRAvFkAJ9zTZ4ZD9qTOoceEi5ICQwBhk6C1ACgiKev Zr1I+ORR6RZutXp2ypQiKvI= =ybp2 -----END PGP SIGNATURE----- |
Jack, 'AES' has copperweld, 18 ga., 250 feet, about $18.00. No idea where to find stainless steel wire, don't need it... 'Doc |
Jack Twilley wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 "Mike" == Mike Coslo writes: [... David mentioned B&W antennas ...] Doc David, The bottom line is that it's a terrible 'amateur' antenna Doc for the price. 'Doc Jack Out of curiosity, what other antenna provides a better Jack cost-benefit ratio while maintaining the same constraints with Jack respect to power, size, and construction? Mike Hmmm, How about an Isotron? 8^) Man, there is a small antenna! They're too spooky for me. I don't understand how they work. No majik there, they work about as well as you would expect an antenna that size to work. That is, not very well. They look cool though! Mike If you take the bands that the B&W performs adequately on, the Mike size ratio between it an a halfwave dipole isn't quite so Mike good. I suppose the FD that is most comparable to my antenna is Mike the BWD 90. It's 90 feet, as we might figure. My dipole is 96 Mike feet. I guess it depends on what you consider "adequate". If your 96-ft dipole provides comparable SWR matches across all the bands the B&W antennas allegedly provide, that'd be pretty impressive. Like the other poster, I noticed that there were no gain figures in the B&W literature, and that does make me suspicious. Right, the two antennas are not quite comparable. I have to use a tuner on my antenna. But that really isn't a handicap IMO. I contest with my rig, and although I have to be careful on 80 meters, I can change bands and set the knobs to their proper positions in just a couple seconds. Mike My dipole cost less than 30 dollars to make. If you count the Mike tuner, I still spent less money. Sure, so did I. And my antenna was messed up the following spring, due to stretched wire, water leaking into critical bits, and more. If you spent less than thirty dollars and used copperweld or stainless steel, then I'd like to know what trucks that wire falls off so I can chase them around town. Never used copperweld, except for twinlead. You can get it pretty easily though. The trick with regular copper is to pre-stretch it. You get a helper or two on each end, and give a good steady pull to stretch it. And yeah, Mother Nature can be a b***h sometimes. My dipole has been up over 2 years now, and is still surviving. That is probably as much luck as my construction genius! 8^) I'll be taking it down for some modifications - I'm going to lengthen it so I can tune 80 meters better, so I'll see soon how the plastic parts held up. I think what I am driving at here is that everything comes at a price, some monetary, some functional. Antennas like the B&W FD are great if you want minimal fuss. That comes at a price in performance though. I went real cheap. The price I pay is using a tuner. That doesn't bother me at all - I'm an inveterate knob twiddler! - Mike KB3EIA - |
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Hash: SHA1 "Mike" == Mike Coslo writes: [...] Mike I think what I am driving at here is that everything comes at a Mike price, some monetary, some functional. Antennas like the B&W FD Mike are great if you want minimal fuss. That comes at a price in Mike performance though. I went real cheap. The price I pay is using Mike a tuner. That doesn't bother me at all - I'm an inveterate knob Mike twiddler! I wholeheartedly agree. There's a price to be paid for every setup -- if you're not paying out of your wallet, you're paying out of your time, or out of your loss of capabilities. It's one of those basic facts of life. I also went dollar-cheap, and I'm getting what I pay for. I'm considering going for something like the B&W for my next location should it be appropriate, to see if I can get my money's worth out of it. Worst case, it ends up getting sold second-hand on eBay. Best case, well, we can all dream. :-) Mike - Mike KB3EIA - Jack. - -- Jack Twilley jmt at twilley dot org http colon slash slash www dot twilley dot org slash tilde jmt slash -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFAqoCpGPFSfAB/ezgRAiuZAKDPcpJKvKr1eiSj6+4d30dGuCsQaQCg0X/2 v/pEGeHTOHAryu0ry+/QQyw= =3Y62 -----END PGP SIGNATURE----- |
On Tue, 18 May 2004 14:31:17 -0700, Jack Twilley Wrote :
snip I wholeheartedly agree. There's a price to be paid for every setup -- Same old story isn't it - "cheap", "well made" and "effective" - choose any two. ie. If it's cheap and effective it aint gonna last...:-) -- Humbug |
Jim Higgins wrote:
On Sun, 16 May 2004 21:13:58 GMT, in , 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? I tend to compare the claims for any antenna to the characteristics of a dummy load and then remember the principle of reciprocity. So for the BW dipole let's see. It's really quiet, esp on the lower frequencies. It's really broad banded. It's not for me. Dummy loads are pretty quiet too aren't they? ;^) - Mike KB3EIA - |
Jim Higgins wrote:
On Sun, 16 May 2004 21:13:58 GMT, in , 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? I tend to compare the claims for any antenna to the characteristics of a dummy load and then remember the principle of reciprocity. So for the BW dipole let's see. It's really quiet, esp on the lower frequencies. It's really broad banded. It's not for me. Doh! I guess that was your point! - Mike KB3EIA - |
Jack Twilley wrote in message ...
Out of curiosity, what other antenna provides a better cost-benefit ratio while maintaining the same constraints with respect to power, size, and construction? A well made G5RV, for one. A well-made W3DZZ trap dipole, for another. W5DXP's "linear tuner" dipole, for a third. Or the classic dipole-with-openline-and-a-real-balanced-tuner for a fourth. All are much more efficient than a T2FD of the same size. The B&W/T2FD is discussed in detail on W4RNL's excellent site (which see). In short, its efficiency is quite low on the lower bands and gets to be almost as good as a halfwave dipole on the upper bands. Their one and only advantage is low SWR over the frequency range. 73 de Jim, N2EY |
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Hash: SHA1 "N2EY" == N2EY writes: N2EY Jack Twilley wrote in message N2EY ... Out of curiosity, what other antenna provides a better cost-benefit ratio while maintaining the same constraints with respect to power, size, and construction? N2EY A well made G5RV, for one. A well-made W3DZZ trap dipole, for N2EY another. W5DXP's "linear tuner" dipole, for a third. Or the N2EY classic dipole-with-openline-and-a-real-balanced-tuner for a N2EY fourth. All are much more efficient than a T2FD of the same N2EY size. The only one of those I haven't seen is the "linear tuner" dipole. N2EY The B&W/T2FD is discussed in detail on W4RNL's excellent site N2EY (which see). In short, its efficiency is quite low on the lower N2EY bands and gets to be almost as good as a halfwave dipole on the N2EY upper bands. Their one and only advantage is low SWR over the N2EY frequency range. I've looked, but the T2FD that's discussed isn't the one I'd be buying, and I'm not sure if that matters. N2EY 73 de Jim, N2EY Jack. - -- Jack Twilley jmt at twilley dot org http colon slash slash www dot twilley dot org slash tilde jmt slash -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFArEYkGPFSfAB/ezgRApFQAKDmCr5rfAAedd+vbyQ/dYZb+r3azgCg/2oD xgXsm3pVOa95PdaCzXYj6Fo= =wiLd -----END PGP SIGNATURE----- |
Jack Twilley wrote:
The only one of those I haven't seen is the "linear tuner" dipole. It's described at: http://www.qsl.net/w5dxp/notuner.htm -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Jack Twilley wrote in message ...
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 "N2EY" == N2EY writes: N2EY Jack Twilley wrote in message N2EY ... Out of curiosity, what other antenna provides a better cost-benefit ratio while maintaining the same constraints with respect to power, size, and construction? N2EY A well made G5RV, for one. A well-made W3DZZ trap dipole, for N2EY another. W5DXP's "linear tuner" dipole, for a third. Or the N2EY classic dipole-with-openline-and-a-real-balanced-tuner for a N2EY fourth. All are much more efficient than a T2FD of the same N2EY size. The only one of those I haven't seen is the "linear tuner" dipole. http://www.qsl.net/w5dxp/notuner.htm N2EY The B&W/T2FD is discussed in detail on W4RNL's excellent site N2EY (which see). In short, its efficiency is quite low on the lower N2EY bands and gets to be almost as good as a halfwave dipole on the N2EY upper bands. Their one and only advantage is low SWR over the N2EY frequency range. I've looked, but the T2FD that's discussed isn't the one I'd be buying, and I'm not sure if that matters. Which one would you be buying and how is it different? Most of the data in the W4RNL site is for a 90' T2FD. When you look at the gain curves, remember that they're in dBi. A simple halfwave dipole has about 2.2 dBi gain. The T2FD isn't a new invention - it was in QST about 1948 as a *receiving* antenna, and that wasn't the first article on it by any means. Government/military folks wanted a receiving antenna that was essentially omnidirectional and would give a decent match to balanced line over the HF frequency range - possibly feeding several receivers via an active receive coupler. Low efficiency below 8 or 10 MHz was no big deal because the receivers had lots of gain, and atmospheric noise dominates in that part of the spectrum even with a poor antenna. Transmitting is another issue. If you want to spend the money for a T2FD, enjoy. But in the same space (T2FDs are not small!) and for the same or less money you could have a much more efficient transmitting antenna. 73 de Jim, N2EY |
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? I have used the BWD-90 for 2 months now, and love it. I live on a city lot, and this antenna fits and performs better than any other antenna I have tried. I've tried shortened 75m dipoles, 40 meter delta loops, and all kinds of slopers. all narrow banded and loaded with city noise. The antenna has made the hobby fun for me again. It is frequency agile, and has a great signal to noise ratio. At 80 meters the antenna is only down 1 db from a standard dipole. At 40 meters it even, there is 1db gain at 20 meters, and 3db at 10m. (B & W,s numbers, not mine). The botton line is if you live in the sticks with all kinds of space, and no noise, you don't need a folded terminated dipole. you can run wire to the cows come home, but it's sure nice in the city. Curt |
Any feed back?
If you desire a single antenna with excellent SWR match at many bands, then I am of the opinion that there is value here. Even the most efficient horizontal dipole is almost useless for DX--the assumed need, not NVIS-- unless it is high up. This is because all low dipoles have low gain at low elevations: Their launch angle is quite high. I would suspect that typical ohmic losses on the BW are 2-5 dB. The mismatch lsses are negligible. Getting this well over a wave high at the lowest freq of operation will afford at least that, and probably more, in a gain differential at low angles, compared to an efficient, low dipole. The point: a high BW antenna will work well. Any low dipole will work poorly. The in-between is a valid issue to ponder. 73, Chip N1IR |
"Fractenna" wrote in message
... Any feed back? If you desire a single antenna with excellent SWR match at many bands, then I am of the opinion that there is value here. Even the most efficient horizontal dipole is almost useless for DX--the assumed need, not NVIS-- unless it is high up. This is because all low dipoles have low gain at low elevations: Their launch angle is quite high. I would suspect that typical ohmic losses on the BW are 2-5 dB. The mismatch lsses are negligible. Getting this well over a wave high at the lowest freq of operation will afford at least that, and probably more, in a gain differential at low angles, compared to an efficient, low dipole. The point: a high BW antenna will work well. Any low dipole will work poorly. The in-between is a valid issue to ponder. 73, Chip N1IR Chip, how did we digress to comparing a "high B&W" to a "low dipole"? When the two are each at their optimal height (and why would we ever compare anything else..) then the dipole has it all over a B&W. I use my (amost 1/2 wave height) dipole only for DX, without a tuner on it's two resonant frequencies and with a tuner on two bands well above, with amazing results. 5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes, if that qualifies as "DX". 73 Jack Painter Virginia Beach, Va |
Chip, how did we digress to comparing a "high B&W" to a "low dipole"? When
the two are each at their optimal height (and why would we ever compare anything else..) then the dipole has it all over a B&W. I use my (amost 1/2 wave height) dipole only for DX, without a tuner on it's two resonant frequencies and with a tuner on two bands well above, with amazing results. 5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes, if that qualifies as "DX". 73 Jack Painter Virginia Beach, Va Hi Jack, It seems relevant to me in two big contexts: (1) why do some folks do well (relatively) with the BW antenna; (2) what does it replace? My response clearly explains (1). In the case of (2), I can think of many circumstances where it is preferable to put one dipole (BW) up high than a slew of dipoles up high. If you have neighbors, you know what I mean:-) Don't know what DX is to me anymore; I have DXCC #1 Honor Roll and haven't been active on the low bands in several years. To someone else, DX is what you haven't heard or worked yet:-) I say go for it. Some folks don't live in a perfect world, Jack, and its good to know when a compromise is a true degradation. A BW antenna, up high, is a good antenna for DX across many bands. It is hardly a dummy load. Hope this helps on this question. 73, Chip N1IR |
With all the hoopla going on for this antenna I was surprised that no
one reported any calculated antenna efficiencies. So I modeled the antenna in free space - to remove environmental influences other than those contained within the antenna itself (terminating resistor and wire loss) - NEC reported the following: Freq. MHz. Efficiency Average Gain Peak Gain MHz % DBi DBi 3.5 9.6 -10.43 -8.49 7.15 41.24 -3.85 -1.33 14.2 23.21 -6.36 -1.59 21.2 30.01 -5.23 -1.36 29 53.81 -2.69 2.17 73 Danny, K6MHE |
Freq. MHz. Efficiency Average Gain Peak Gain
MHz % DBi DBi 3.5 9.6 -10.43 -8.49 7.15 41.24 -3.85 -1.33 14.2 23.21 -6.36 -1.59 21.2 30.01 -5.23 -1.36 29 53.81 -2.69 2.17 73 Danny, K6MHE 80M is a bit lower than I expect, but not by much:referring to dBmax values. It probably picks up a dB or more at the high end of 75M. It doesn't mean much to discuss 'average gain' values unless its an isotropic or (within a certain elevation range) an omni antenna. Sometimes vertical dipoles are described as having an 'average gain', but I haven't seen that used for horizontal ones:-) The pattern is not bidirectional on the higher bands BTW... ar least that's what intuition tells me... 73, Chip N1IR |
"Fractenna" wrote Chip, how did we digress to comparing a "high B&W" to a "low dipole"? When the two are each at their optimal height (and why would we ever compare anything else..) then the dipole has it all over a B&W. I use my (amost 1/2 wave height) dipole only for DX, without a tuner on it's two resonant frequencies and with a tuner on two bands well above, with amazing results. 5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes, if that qualifies as "DX". 73 Jack Painter Virginia Beach, Va Hi Jack, It seems relevant to me in two big contexts: (1) why do some folks do well (relatively) with the BW antenna; (2) what does it replace? My response clearly explains (1). In the case of (2), I can think of many circumstances where it is preferable to put one dipole (BW) up high than a slew of dipoles up high. If you have neighbors, you know what I mean:-) Don't know what DX is to me anymore; I have DXCC #1 Honor Roll and haven't been active on the low bands in several years. To someone else, DX is what you haven't heard or worked yet:-) I say go for it. Some folks don't live in a perfect world, Jack, and its good to know when a compromise is a true degradation. A BW antenna, up high, is a good antenna for DX across many bands. It is hardly a dummy load. Hope this helps on this question. 73, Chip N1IR Hi Chip, Yes it does help to hear it works reasonably well when other circumstances limit the options. I can't for instance squeeze more long dipoles up, but I could try one of the T2 varieties someday. Since the dipole I now have works across many bands well with a tuner, the B&W could never replace it, but it might augment it someday. Cheers and thanks, Jack Painter Virginia Beach, Va |
Jack Painter wrote:
"Fractenna" wrote Chip, how did we digress to comparing a "high B&W" to a "low dipole"? When the two are each at their optimal height (and why would we ever compare anything else..) then the dipole has it all over a B&W. I use my (amost 1/2 wave height) dipole only for DX, without a tuner on it's two resonant frequencies and with a tuner on two bands well above, with amazing results. 5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes, if that qualifies as "DX". 73 Jack Painter Virginia Beach, Va Hi Jack, It seems relevant to me in two big contexts: (1) why do some folks do well (relatively) with the BW antenna; (2) what does it replace? My response clearly explains (1). In the case of (2), I can think of many circumstances where it is preferable to put one dipole (BW) up high than a slew of dipoles up high. If you have neighbors, you know what I mean:-) Don't know what DX is to me anymore; I have DXCC #1 Honor Roll and haven't been active on the low bands in several years. To someone else, DX is what you haven't heard or worked yet:-) I say go for it. Some folks don't live in a perfect world, Jack, and its good to know when a compromise is a true degradation. A BW antenna, up high, is a good antenna for DX across many bands. It is hardly a dummy load. Hope this helps on this question. 73, Chip N1IR Hi Chip, Yes it does help to hear it works reasonably well when other circumstances limit the options. I can't for instance squeeze more long dipoles up, but I could try one of the T2 varieties someday. Since the dipole I now have works across many bands well with a tuner, the B&W could never replace it, but it might augment it someday. Cheers and thanks, Jack Painter Virginia Beach, Va As I have said many times here, The B&W antenna is for those that need it not those who can/need/want to use other means of connecting with the ether. It is definitely not the most efficient means of wireless communications but it is definitely fool proof in operation. Dave WD9BDZ |
Hi Jack,
It certainly is relevant to ask whether line/antenna mismatch losses are lower with the ATU across all the bands, compared to the ohmic matching of the T2. In any case, nothing is a substitute for getting the antenna up high--but you know this:-) 73, Chip N1IR |
As I have said many times here, The B&W antenna is for those that need
it not those who can/need/want to use other means of connecting with the ether. It is definitely not the most efficient means of wireless communications but it is definitely fool proof in operation. Dave WD9BDZ From what I can see, this is basically a military antenna sold to hams, hence the high price. I think it is pretty reliable for what it delivers, and at 65 feet long, that's a pretty good solution many times. Just get it HIGH up. Incidentally, I am at W3EF's right now and guest op'ing the night. He typically works EU on 40M in mid-afternoon with 150 watts. Of course, the tower IS at 126 feet....:-) His option was 3 els linear loaded at 126 feet vs 5 els trapped at 50 feet. I don't think he regrets the decision. Remember the other added bonus: less neighbor RFI with a higher antenna! 73, Chip N1IR |
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