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#11
February 3rd 04, 10:38 AM
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"RHF" wrote in message om... KW, I have bought two Kiwa MW Air Core Loop Antennas. A Used one for $248 and the other 'Like New in the Box' with all the Documents and Gear for $425. Is it really that much better than a Select-A-Tenna? I've pulled in a lot of stations very clearly with my SAT. DeWayne You Got To Keep-On KEEPING-ON ! iaf... ~ RHF = = = If At First... You Don't Succeed - Try - Try Again ! . . = = = "Ken Wilson" = = = wrote in message ... ----- Original Message ----- From: "RHF" Newsgroups: rec.radio.shortwave,rec.radio.swap Sent: Monday, February 02, 2004 2:41 AM Subject: FA: Kiwa Mediumwave Loop FO&A, So... How did all these Loops finally close out and infact did any of the eBay Bidders "PAY TOO MUCH" - You Be The Judge: DISCLAIMER: These were NOT My eBay Auctions and I am NOT Associated with the Seller [.] Hello RHF & the Group, I don't know about most of you .....but the only way I can get what I would call a good price on Ebay SWL equip.... is if it is not a popular item or better yet ....not many know it is there. I hope to find items that are missspellledd or listed wrong. 73, Ken |
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#12
February 3rd 04, 08:23 PM
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DeWayne,
In One Word: "YES" Read the Information presented on the Kiwa MW Air Core Loop Antenna WebPage. http://www.kiwa.com/kiwaloop.html iane ~ RHF .. .. = = = "DeWayne" = = = wrote in message ... "RHF" wrote in message om... KW, I have bought two Kiwa MW Air Core Loop Antennas. A Used one for $248 and the other 'Like New in the Box' with all the Documents and Gear for $425. Is it really that much better than a Select-A-Tenna? I've pulled in a lot of stations very clearly with my SAT. DeWayne You Got To Keep-On KEEPING-ON ! iaf... ~ RHF = = = If At First... You Don't Succeed - Try - Try Again ! . . = = = "Ken Wilson" = = = wrote in message ... ----- Original Message ----- From: "RHF" Newsgroups: rec.radio.shortwave,rec.radio.swap Sent: Monday, February 02, 2004 2:41 AM Subject: FA: Kiwa Mediumwave Loop FO&A, So... How did all these Loops finally close out and infact did any of the eBay Bidders "PAY TOO MUCH" - You Be The Judge: DISCLAIMER: These were NOT My eBay Auctions and I am NOT Associated with the Seller [.] Hello RHF & the Group, I don't know about most of you .....but the only way I can get what I would call a good price on Ebay SWL equip.... is if it is not a popular item or better yet ....not many know it is there. I hope to find items that are missspellledd or listed wrong. 73, Ken |
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#14
February 17th 04, 03:43 AM
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FO&A,
This "UN-USED" Kiwa High Performance MW Loop Antenna. Closed Out with a Final Bid (Selling Price) of $760. [New Record ?] NOTE: There were Nine Bids with Seven of the Bids (7/9) being place in the last 40 Minutes of the Auction. FWIW: Maybe Kiwa should get back into the MW Loop Antenna 'business'. ~ RHF .. .. = = = (RHF) = = = wrote in message . com... KW, FYI: Here is an "UN-USED" Kiwa High Performance MW Loop Antenna eBay Auction Item Number: 3076899263 It is already up to $450 with Two(2) Bids both by the same Bidder. I guess he really, Really. REALLY ! - Wants It  ) ;-} !]jtf ~ RHF . . = = = (RHF) = = = wrote in message . com... KW, I have bought two Kiwa MW Air Core Loop Antennas. A Used one for $248 and the other 'Like New in the Box' with all the Documents and Gear for $425. You Got To Keep-On KEEPING-ON ! iaf... ~ RHF = = = If At First... You Don't Succeed - Try - Try Again ! . . = = = "Ken Wilson" = = = wrote in message ... ----- Original Message ----- From: "RHF" Newsgroups: rec.radio.shortwave,rec.radio.swap Sent: Monday, February 02, 2004 2:41 AM Subject: FA: Kiwa Mediumwave Loop FO&A, So... How did all these Loops finally close out and infact did any of the eBay Bidders "PAY TOO MUCH" - You Be The Judge: DISCLAIMER: These were NOT My eBay Auctions and I am NOT Associated with the Seller [.] Hello RHF & the Group, I don't know about most of you .....but the only way I can get what I would call a good price on Ebay SWL equip.... is if it is not a popular item or better yet ....not many know it is there. I hope to find items that are missspellledd or listed wrong. 73, Ken .. |
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#15
February 17th 04, 11:42 AM
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"DeWayne" wrote in message ...
"RHF" wrote in message om... KW, I have bought two Kiwa MW Air Core Loop Antennas. A Used one for $248 and the other 'Like New in the Box' with all the Documents and Gear for $425. Is it really that much better than a Select-A-Tenna? I've pulled in a lot of stations very clearly with my SAT. DeWayne I don't know what a Select-A-Tenna is, but a loop is a loop is a loop. There is no magical quality that any one loop would have over another besides voltage. The larger the loop, the higher the voltage out. But the directional qualities are the same. Several hundred bucks for a MW loop is ridiculous. I'd have to be on some kind of drugs to pay that much. My loops are all free. And they work as well as any other loop, not counting extra tricks like phasing, etc. The size of the loop, IE: bigger, is only important if you actually have a low enough noise floor to take advantage of it. You have to be out in the country in most cases. Here in the big breast bearing city of Houston, my smaller loops work as well as the bigger ones. If the station listened to is strong, a ferrite stick is about as good as anything. Even my fairly small 16 inch round loop gives me enough voltage to be well over the city noise floor, with no preamp used. Only a coupling loop. It covers 500-2000 kc. Lower into LW, if I tack on extra fixed caps in parallel with the variable. To see an improvement over a normal bi-directional loop, a K9AY terminated loop, or something along those lines can be used. That IS an improvement over the average loop as it's unidirectional. Most run a pair, switched to change in 4 directions. Looks kinda like an eggbeater of sorts. MK |
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#16
February 17th 04, 12:32 PM
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Mark Keith wrote:
I don't know what a Select-A-Tenna is, but a loop is a loop is a loop. There is no magical quality that any one loop would have over another besides voltage. The larger the loop, the higher the voltage out. But the directional qualities are the same. Several hundred bucks for a MW loop is ridiculous. I'd have to be on some kind of drugs to pay that much. My loops are all free. And they work as well as any other loop, not counting extra tricks like phasing, etc. The size of the loop, IE: bigger, is only important if you actually have a low enough noise floor to take advantage of it. You have to be out in the country in most cases. Here in the big breast bearing city of Houston, my smaller loops work as well as the bigger ones. If the station listened to is strong, a ferrite stick is about as good as anything. Even my fairly small 16 inch round loop gives me enough voltage to be well over the city noise floor, with no preamp used. Only a coupling loop. It covers 500-2000 kc. Lower into LW, if I tack on extra fixed caps in parallel with the variable. To see an improvement over a normal bi-directional loop, a K9AY terminated loop, or something along those lines can be used. That IS an improvement over the average loop as it's unidirectional. Most run a pair, switched to change in 4 directions. Looks kinda like an eggbeater of sorts. MK 1. The depth of the null is different between loops (and loop arrangements) 2. And then there's the matter of pointing it. There are two patterns for small antennas, a magentic field pattern and an electic field pattern. The radio hears both, and _they don't null at the same place_. A _loop_ responds mostly to magnetic field, but there is an electric field response some number of dB down. That number of dB down limits the depth of the null you can get. The fields can't be used to cancel each other because they're in quadrature. 1. Kiwa builds an electric-field balanced loop that has the lowest possible response to electric fields, and so the magnetic field null is then very deep. 2. Kiwa's is on an azimuth-elevation mount. Every time you get twice as close to the true null, you get 6dB more null. Soon you're dealing with fractions of a degree. The ability to adjust to fractions of a degree limits the null depth, the finer the better. The Kiwa is about the best you'll find. It's an active loop, so you can feed the radio a high level of signal, which makes the radio's native loop response less important if you air-couple it. -- Ron Hardin On the internet, nobody knows you're a jerk. |
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#17
February 17th 04, 09:51 PM
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Ron Hardin wrote in message
1. The depth of the null is different between loops (and loop arrangements) True, but this is a design issue, not money..:/ 2. And then there's the matter of pointing it. There are two patterns for small antennas, a magentic field pattern and an electic field pattern. The radio hears both, and _they don't null at the same place_. A _loop_ responds mostly to magnetic field, but there is an electric field response some number of dB down. That number of dB down limits the depth of the null you can get. The fields can't be used to cancel each other because they're in quadrature. 1. Kiwa builds an electric-field balanced loop that has the lowest possible response to electric fields, and so the magnetic field null is then very deep. Some of mine are too, but I don't find the difference between one of those to say my round 16 inch "normal" loop to be that great. "12 turns and a 2 turn coupling loop" It's mainly an issue of good balance, and reducing common mode currents, etc I think. I get very good nulls with mine. I've never actually tested using a step attenuator or anything, but it's common to knock a loud local BC station down 20-30db or more going by the s meter. I've seen 40 db a few times. In the day, most all out of town groundwave signals are totally gone if I rotate against them. As far as balance, I found better balance using the coupling loop, than directly feeding the loop. I noticed a slight skew off true direction when directly fed. I notice many people complain about a lack of nulls or directivity at night, but mine does fairly well. Maybe not as "dead air gone" as in the daytime nulls, but still very effective. Thats where adjusting the tilt can help a bit. 2. Kiwa's is on an azimuth-elevation mount. Every time you get twice as close to the true null, you get 6dB more null. Soon you're dealing with fractions of a degree. The ability to adjust to fractions of a degree limits the null depth, the finer the better. The Kiwa is about the best you'll find. Mine is also. I can turn it around on it's stand, and I can also adjust the tilt. I usually end up with mine pointing downwards just a tad for the best nulls. My nulls are very sharp. Just a fraction of an inch in rotation as I turn it can mean quite a few db in the null depth. It's an active loop, so you can feed the radio a high level of signal, which makes the radio's native loop response less important if you air-couple it. That can be handy, but again preamps, etc can be built fairly cheap. I don't need one on mine. Plenty of signal, and I can kick the radio's preamp on if I want more. But I prefer not to use it, as it just pumps up the noise. I guess to each his own, but I'll never spend several hundred bucks for a small loop when they can be built for a fraction of that. It certainly doesn't require near that kind of money to copy what they are doing. MK |
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