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#1
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I'm still trying to decide on a ready-made HF antenna. I have a couple more
questions. Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Does the G5RV really need an antenna tuner? Wow, there's a 7:1 price difference here! Hope to be QSOing soon, instead of emailing. -- Bob D. ND9B |
#2
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Bob D. wrote:
Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Any antenna can be equipped with a resistor that will dissipate so much RF energy that a tuner is not required. A dummy load will do the same thing. One review of the BWD-90 says it is the biggest air-cooled dummy load in the world. http://www.eham.net/reviews/detail/1016 Does the G5RV really need an antenna tuner? Yes, unless you install a resistor at the coax/twinlead junction. http://www.vk1od.net/G5RV/ -- 73, Cecil http://www.w5dxp.com |
#3
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I used the B&W for a while here, and find the AlphaDelta DX-CC Works better
and can handle the Amplifier.. BEWARE the ratings on the B&W!.. The antenna is good to 250W RTTY or full duty use, and 500W Voice.. Spend your money on a Different antenna!.. N8NOE-Jeff Bob D. wrote: Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Any antenna can be equipped with a resistor that will dissipate so much RF energy that a tuner is not required. A dummy load will do the same thing. One review of the BWD-90 says it is the biggest air-cooled dummy load in the world. http://www.eham.net/reviews/detail/1016 Does the G5RV really need an antenna tuner? Yes, unless you install a resistor at the coax/twinlead junction. http://www.vk1od.net/G5RV/ |
#4
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Bob D. wrote:
I'm still trying to decide on a ready-made HF antenna. I have a couple more questions. Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Does the G5RV really need an antenna tuner? Wow, there's a 7:1 price difference here! Hope to be QSOing soon, instead of emailing. Bob, check out www.cebik.com for an anlysis of the B&W antennas, G5RV's and others. The B&W antenna radiates better than a dummy load of course, but is less efficient than alternative antennas burdened by other constraints. We haven't quite reached the "one size fits all" stratum yet. 73, Chuck, NT3G ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#5
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On Fri, 27 Apr 2007 08:12:26 -0400, Bob D. wrote:
Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Good afternoon, Bob. I agree with Chuck and Cecil. The B&Ws are radiating dummy loads, nothing more. One time, I was on a 75-meter net with another station about 15 miles from me, and several other stations elsewhere in the state, as far as 150 miles away. The other station (the one 15 miles away) was running 100 watts and a B&W at 25 feet. I was running a grand total of FIVE (5) watts and a cut dipole at 20 feet. My 5 watts was reported as stronger than the other station's 100 watts. I read another report in this newsgroup from another amateur who said pretty much the same thing except in his case it was a MARS net, I think, somewhere above the top end of 75 meters. For the price of a B&W, or perhaps just a bit more, you can buy the materials to make an 80-meter dipole fed with ladder line, and an autotuner e.g. from LDG that will let you run that antenna on 80 through 10. That's what I would recommend if you want easy and relatively inexpensive multiband operation. |
#6
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Rick (W-A-one-R-K-T) wrote:
On Fri, 27 Apr 2007 08:12:26 -0400, Bob D. wrote: Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Good afternoon, Bob. I agree with Chuck and Cecil. The B&Ws are radiating dummy loads, nothing more. One time, I was on a 75-meter net with another station about 15 miles from me, and several other stations elsewhere in the state, as far as 150 miles away. The other station (the one 15 miles away) was running 100 watts and a B&W at 25 feet. I was running a grand total of FIVE (5) watts and a cut dipole at 20 feet. My 5 watts was reported as stronger than the other station's 100 watts. I read another report in this newsgroup from another amateur who said pretty much the same thing except in his case it was a MARS net, I think, somewhere above the top end of 75 meters. For the price of a B&W, or perhaps just a bit more, you can buy the materials to make an 80-meter dipole fed with ladder line, and an autotuner e.g. from LDG that will let you run that antenna on 80 through 10. That's what I would recommend if you want easy and relatively inexpensive multiband operation. Let's not overstate the case against the B&W. Cebik's modeling shows a ~6 dB penalty for the 90' B&W at 6 MHz and above, while at 4 MHz, it is more like 12 dB, which is very roughly commensurate with your anecdotal report. Obviously, one does not endure such losses without countervailing benefits which, in this case, are superb frequency agility, simplicity, and reliability. While I wouldn't own one, others do. Chuck, NT3G ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#7
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Bob D. wrote:
I'm still trying to decide on a ready-made HF antenna. I have a couple more questions. Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Does the G5RV really need an antenna tuner? Wow, there's a 7:1 price difference here! Hope to be QSOing soon, instead of emailing. The B&W (and all of the essentially identical antennas which are a folded dipole of some sort with a big resistor) are an interesting solution to a system engineering problem. Sure, they're hideously inefficient, but, they don't require a tuner, and if you're not power limited, you can overcome the inefficiency by just turning up the amp. It's no different than putting a 3dB pads on the ports of a mixer to make them less sensitive to the match. You take a efficiency hit, but you pick up overall system insensitivity to component variations, etc. A terminated folded dipole and a broadband solid state amp is not a bad system solution for someone who needs a broadband (2-30MHz) system that is simple to deploy and has essentially instantaneous frequency change ability. Hmmm.. folks with ALE or HF frequency hopping radios in a tactical environment. And who buys these sorts of things: military and diplomatic folks, who aren't power constrained, need fast frequency changes and simple installation, and aren't concerned about saving every penny. In that market, a few hundred dollars more or less makes almost no difference. Jim, W6RMK |
#8
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Jim Lux wrote:
Bob D. wrote: I'm still trying to decide on a ready-made HF antenna. I have a couple more questions. Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Does the G5RV really need an antenna tuner? Wow, there's a 7:1 price difference here! Hope to be QSOing soon, instead of emailing. The B&W (and all of the essentially identical antennas which are a folded dipole of some sort with a big resistor) are an interesting solution to a system engineering problem. Sure, they're hideously inefficient, but, they don't require a tuner, and if you're not power limited, you can overcome the inefficiency by just turning up the amp. It's no different than putting a 3dB pads on the ports of a mixer to make them less sensitive to the match. You take a efficiency hit, but you pick up overall system insensitivity to component variations, etc. A terminated folded dipole and a broadband solid state amp is not a bad system solution for someone who needs a broadband (2-30MHz) system that is simple to deploy and has essentially instantaneous frequency change ability. Hmmm.. folks with ALE or HF frequency hopping radios in a tactical environment. And who buys these sorts of things: military and diplomatic folks, who aren't power constrained, need fast frequency changes and simple installation, and aren't concerned about saving every penny. In that market, a few hundred dollars more or less makes almost no difference. Jim, that is an interesting - and correct - outlook on the folded dipole. That's why it is a good solution for people who aren't constrained in power. For Hams, I would think it isn't a great solution, although if run at full legal power it might be okay. For Bob: Don't be afraid of a tuner. Look at it as just another bit of circuitry. Turning knobs is part of the fun of Ham radio. That G5RV will need a tuner. A suggestion for an antenna: Get a ladder line fed dipole of 130 feet. I think AES sells them for around 35 dollars or so. Use a tuner on it. If you want automation, there are automatic tuners that will handle balanced line. MFJ makes one for example. You'll have a nice all band antenna, if a little "lobey" on the upper bands. And you won't have the loss of the Folded dipole. - 73 de Mike KB3EIA - |
#9
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![]() "Bob D." wrote in message m... I'm still trying to decide on a ready-made HF antenna. I have a couple more questions. Can the Barker & Williamson's BWD-90 really be used without an antenna tuner? Does the G5RV really need an antenna tuner? Wow, there's a 7:1 price difference here! Hope to be QSOing soon, instead of emailing. -- Bob D. ND9B Just for comparison, take a look at www.k1kek.com. It's called the Cobra Ultralite and comes in 2 versions. 73 feet and 140 feet for 80-10 coverage and 160-10 respectively. I run the longer one with an LDG autotuner. I don't have comparative data, and I'm not trying to argue about which antenna is "best"; just the fact that the Cobra works decently, slightly better than the B & W and is less obtrusive. It carries up to 1000 watts and seems to work smoothely without any objections thru out its range. Most anything is a compromise unless it is a resonant, dedicated antenna; it's all in what you are looking for. The Cobra DOES want a tuner, however. Again, an opinion, but I don't like the B & W. 73 K4KWH |
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