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#1
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Do you currently use a longwire or dipole or have the real estate for one?
Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. |
#2
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![]() Seeing-I-dawg wrote: Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. First, please understand and accept that I have nothing against the Wellbrook company or thier products. Their web page has clearly helped many newbie SWL learn how to errect a "long" wire antenna. And many people swear by all of their loops. However, my experience suggests loops may not be the do all end all. For a alternative perspective please read the research by Dallas Lanford at http://www.kongsfjord.no/ "Measurements of Some Antennas Signal to Man Made Noise Ratios" Every situation is different. And the guy I traded theALA 1530 to loves it. Perhaps under extreme noise situations loops are better. My recent experiments mirrored Dallas' experiences. My "shack" is still disassembled. I hope to have it up and running by the weekend. 2 days of rain really messed with my plans. Terry |
#4
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In article .com,
"Steve" wrote: wrote: Seeing-I-dawg wrote: Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. First, please understand and accept that I have nothing against the Wellbrook company or thier products. Their web page has clearly helped many newbie SWL learn how to errect a "long" wire antenna. And many people swear by all of their loops. However, my experience suggests loops may not be the do all end all. For a alternative perspective please read the research by Dallas Lanford at http://www.kongsfjord.no/ "Measurements of Some Antennas Signal to Man Made Noise Ratios" Every situation is different. And the guy I traded theALA 1530 to loves it. Perhaps under extreme noise situations loops are better. My recent experiments mirrored Dallas' experiences. My "shack" is still disassembled. I hope to have it up and running by the weekend. 2 days of rain really messed with my plans. I have an open mind on this issue. I use one of the Wellbrook loops and I like it, but I'm perfectly prepared to believe that a small active vertical can be just as quiet. What generates confusion about this issue are the conflicting reports one hears and even the conflicting experimental results one reads about. I visited the http://www.kongsfjord.no site and found it very interesting. However, if you look at some of the reviews available on the Wellbrook website, you'll see different tests and comparisons that yield results that are much more favorable to the Wellbrooks. There may well be something wrong with the tests and comparisons carried out in those reviews. I don't see anything obviously suspect about them, but I don't have the technical expertise that some of the folks in this group have. In any case, I think it's this kind of data that accounts for the reputation the Wellbrook loops have as being extremely quiet antennas. One problem of post in a public news group is that at times I feel like I'm talking to a brick wall. Most peoples experience in high noise areas will favor a loop antenna over a dipole for locally picked up noise. This is an expected theoretical result of local induction fields affecting loop and dipole antennas. The IP2 and IP3 differences in the active antennas are due to the amplifier design not the antenna. -- Telamon Ventura, California |
#5
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![]() Telamon wrote: In article .com, "Steve" wrote: wrote: Seeing-I-dawg wrote: Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. First, please understand and accept that I have nothing against the Wellbrook company or thier products. Their web page has clearly helped many newbie SWL learn how to errect a "long" wire antenna. And many people swear by all of their loops. However, my experience suggests loops may not be the do all end all. For a alternative perspective please read the research by Dallas Lanford at http://www.kongsfjord.no/ "Measurements of Some Antennas Signal to Man Made Noise Ratios" Every situation is different. And the guy I traded theALA 1530 to loves it. Perhaps under extreme noise situations loops are better. My recent experiments mirrored Dallas' experiences. My "shack" is still disassembled. I hope to have it up and running by the weekend. 2 days of rain really messed with my plans. I have an open mind on this issue. I use one of the Wellbrook loops and I like it, but I'm perfectly prepared to believe that a small active vertical can be just as quiet. What generates confusion about this issue are the conflicting reports one hears and even the conflicting experimental results one reads about. I visited the http://www.kongsfjord.no site and found it very interesting. However, if you look at some of the reviews available on the Wellbrook website, you'll see different tests and comparisons that yield results that are much more favorable to the Wellbrooks. There may well be something wrong with the tests and comparisons carried out in those reviews. I don't see anything obviously suspect about them, but I don't have the technical expertise that some of the folks in this group have. In any case, I think it's this kind of data that accounts for the reputation the Wellbrook loops have as being extremely quiet antennas. - One problem of post in a public news group is - that at times I feel like I'm talking to a brick wall. Telamon - You Just Keep-On Writing : Cause This Brick Wall Is Listening ! ~ RHF - Most peoples experience in high noise areas will favor - a loop antenna over a dipole for locally picked up noise. OK ! - This is an expected theoretical result of local induction - fields affecting loop and dipole antennas. OK ! - The IP2 and IP3 differences in the active antennas - are due to the amplifier design not the antenna. The ablity to 'rotate' a small Loop Antenna to Null-Out a Local Offending Radio Station {Signal Source} does have to be factored into the practical {use} equation. -vice- A small Vertical Whip Antenna {Omni-Directional} : Given that the Amplifier used with both Antennas has the same characteristics. However - The Practical {Use} Equation {Societal Factoring} may make the 'near invisibility' of the Small {Short-and-Thin} Vertical Whip Antenna the only realistic choice for an Antenna by a Shortwave Listener (SWL) "When NO Antenna Is Allowed." what antenna ? i don't see an antenna : i ain't got no stinking antenna ~ RHF |
#6
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![]() wrote in message oups.com... Seeing-I-dawg wrote: Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. First, please understand and accept that I have nothing against the Wellbrook company or thier products. Their web page has clearly helped many newbie SWL learn how to errect a "long" wire antenna. And many people swear by all of their loops. However, my experience suggests loops may not be the do all end all. For a alternative perspective please read the research by Dallas Lanford at http://www.kongsfjord.no/ "Measurements of Some Antennas Signal to Man Made Noise Ratios" Every situation is different. And the guy I traded theALA 1530 to loves it. Perhaps under extreme noise situations loops are better. My recent experiments mirrored Dallas' experiences. My "shack" is still disassembled. I hope to have it up and running by the weekend. 2 days of rain really messed with my plans. Terry Terry, this post wasn't intended as an addendum to my previous post to you about horizontal loops. I don't/can't dispute the claims about verticals Vs. loops regarding noise. Generally, a vertical antenna is ideal for DXing since its main "lobe" is towards the horizon (in all directions). But I know you knew that. Could that account for the difference in S/MMN ratio in the Kongsfjord comparison? The two main practical advantages of loops is steerability or nulling with relatively small loops and inherently broadbanded performance with relatively large (full wave) loops. The Wellbrook ALA1530+ claims both - broadband performance using a broadband amplifier and steerability using a small "shielded" loop. The ALA1530+ design is different from the ALA100 in that the ALA1530+ "loop" is inside an aluminum tube/shield. Alegedly this shield(?) rejects the nearby Electric-field which supposedly contains the noise component and amplifies the Magnetic-field which supposedly does not contain the noise [Electro-Magnetic wave = RF]. The ALA100 wire antenna component has no shield so how can it reject nearby Electric-fields containing noise? Additionally, in the Kongsfjord power line comparison (45Ft vertical Vs. Loop) the vertical's main lobe is at the horizon (under the powerline). The lobes of the loop are very much like that of a dipole (above the horizon) - more closely aimed at the powerline. Therefor, I think the Kongsfjord comparison is missplaced. But I am not versed with the noise argument related to loops Vs. verticals. My point to my original post in this thread was that if you already have a dipole or longwire (which is inherently NOT broadbanded) you can use the ALA100 to convert them into a loop. The Wellbrook ALA100 product is simply a broadband amplifier (I suspect similiar to the 1530). It does not include any "antenna" or coax. You supply the antenna wire yourself - an existing dipole or longwire folded into some resemblance to a large broadbanded loop. The shape is not critical as long as the wires are not too close. Converting a dipole or longwire into a broadbanded loop and adding a broadbanded amplifier like the ALA100 seems like a good idea. Although the ALA100 was meant to be used with a relatively medium sized rotatable vertical loop, http://www.wellbrook.uk.com/ALA100b.html Wellbrook's email in essence said it will work with any reasonably sized loop oriented in any plane - vertically or horizontally. My antenna goal is to have one antenna and to squeeze as much performance out of it on as many frequencies (500KHz-30MHz) as possible. That, my friend, can be most closely accomplished with a large loop. However, I am intriqed by the 15ft vertical that is diagramed at the Kongsfjord noise measurments link. There are no ideal antennas. Just antennas with ideal applications. |
#7
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Terry,
Please read the last paragraph of this 1991 paper: http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf "Seeing-I-dawg" wrote in message ... wrote in message oups.com... Seeing-I-dawg wrote: Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. First, please understand and accept that I have nothing against the Wellbrook company or thier products. Their web page has clearly helped many newbie SWL learn how to errect a "long" wire antenna. And many people swear by all of their loops. However, my experience suggests loops may not be the do all end all. For a alternative perspective please read the research by Dallas Lanford at http://www.kongsfjord.no/ "Measurements of Some Antennas Signal to Man Made Noise Ratios" Every situation is different. And the guy I traded theALA 1530 to loves it. Perhaps under extreme noise situations loops are better. My recent experiments mirrored Dallas' experiences. My "shack" is still disassembled. I hope to have it up and running by the weekend. 2 days of rain really messed with my plans. Terry Terry, this post wasn't intended as an addendum to my previous post to you about horizontal loops. I don't/can't dispute the claims about verticals Vs. loops regarding noise. Generally, a vertical antenna is ideal for DXing since its main "lobe" is towards the horizon (in all directions). But I know you knew that. Could that account for the difference in S/MMN ratio in the Kongsfjord comparison? The two main practical advantages of loops is steerability or nulling with relatively small loops and inherently broadbanded performance with relatively large (full wave) loops. The Wellbrook ALA1530+ claims both - broadband performance using a broadband amplifier and steerability using a small "shielded" loop. The ALA1530+ design is different from the ALA100 in that the ALA1530+ "loop" is inside an aluminum tube/shield. Alegedly this shield(?) rejects the nearby Electric-field which supposedly contains the noise component and amplifies the Magnetic-field which supposedly does not contain the noise [Electro-Magnetic wave = RF]. The ALA100 wire antenna component has no shield so how can it reject nearby Electric-fields containing noise? Additionally, in the Kongsfjord power line comparison (45Ft vertical Vs. Loop) the vertical's main lobe is at the horizon (under the powerline). The lobes of the loop are very much like that of a dipole (above the horizon) - more closely aimed at the powerline. Therefor, I think the Kongsfjord comparison is missplaced. But I am not versed with the noise argument related to loops Vs. verticals. My point to my original post in this thread was that if you already have a dipole or longwire (which is inherently NOT broadbanded) you can use the ALA100 to convert them into a loop. The Wellbrook ALA100 product is simply a broadband amplifier (I suspect similiar to the 1530). It does not include any "antenna" or coax. You supply the antenna wire yourself - an existing dipole or longwire folded into some resemblance to a large broadbanded loop. The shape is not critical as long as the wires are not too close. Converting a dipole or longwire into a broadbanded loop and adding a broadbanded amplifier like the ALA100 seems like a good idea. Although the ALA100 was meant to be used with a relatively medium sized rotatable vertical loop, http://www.wellbrook.uk.com/ALA100b.html Wellbrook's email in essence said it will work with any reasonably sized loop oriented in any plane - vertically or horizontally. My antenna goal is to have one antenna and to squeeze as much performance out of it on as many frequencies (500KHz-30MHz) as possible. That, my friend, can be most closely accomplished with a large loop. However, I am intriqed by the 15ft vertical that is diagramed at the Kongsfjord noise measurments link. There are no ideal antennas. Just antennas with ideal applications. |
#8
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![]() Please read the last paragraph of this 1991 paper: http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf Generally, a vertical antenna is ideal for DXing since its main "lobe" is towards the horizon (in all directions). But I know you knew that. Could that account for the difference in S/MMN ratio in the Kongsfjord comparison? .... Additionally, in the Kongsfjord power line comparison (45Ft vertical Vs. Loop) the vertical's main lobe is at the horizon (under the powerline). The lobes of the loop are very much like that of a dipole (above the horizon) - more closely aimed at the powerline. Addition part II: The powerline noise is horizontally polarized while a vertical antenna is vertically polarized. The noise was 90 degrees out of phase [typically a difference of what? 6db?]. Thus the vertical antenna in this situation was at a distinct advantage. Out of phase and major lobe pointed away from the powerline. A square loop, as is the ALA100 loop, is both horizontally and vertically polarized. Thus more sensitive to receiving the horizontally polarized powerline noise compared to a vertical antenna. |
#9
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Here's another idea:
Custom made, 5ft square, rotatable loop using Wellbrook ALA-100 amp "...so far it looks to be a fine replacement for my 700 ft. NW Beverage antenna..." http://sdr-1000.blogspot.com/2006/07...0-antenna.html __________________________________________________ ____________ "Seeing-I-dawg" wrote in message ... Do you currently use a longwire or dipole or have the real estate for one? Have you been considering the ALA1530+ instead? I exchanged emails with Wellbrook about using the ALA100 with my current 70M fullwave Horizontal loop. About Horizontal loops http://www.cebik.com/wire/hl.html http://www.cebik.com/fdim/atl1.html http://www.cebik.com/wire/horloop.html About ALA100 http://www.wellbrook.uk.com/ALA100b.html The ALA100 will allow me to use a coax feeder instead of the noise prone 450ohm ladder-line and dispense with the antenna tuner/matchbox. Per Wellbrook, "You may also find that a smaller vertical loop with ALA100 will give better directivity for MW plus very high gain at HF. The ALA100 will out perform the ALA1530+ , because the loop area is much larger." So if you are considering a ALA1530+ and are currently occupying real estate with a long-wire or dipole, you may consider joining the ends with the ALA100 for a loop in either the horizontal or vertical plane. Here's to the '06/'07 DXing season! Post your logs and good luck. |
#10
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![]() On Oct 4, 6:36 pm, "Seeing-I-dawg" wrote: Terry, Please read the last paragraph of this 1991 paper:http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf Yep, the directivity of a loop is what the "magic" is all about. Dallas' active dipole exhibited better, as in a better null, directivity from 100KHz (loran) to CB. A good buddy ratchet mouth about 3 miles from me makes a great far field test signal. The Feb 1955 "Wireless Engineer" paper by J.S.Belrose gives some very usefull info on loop. I am not saying loops have no place. Jeff, the guy I traded the wellbrook to, loves it. In his RF hell it works better then anyother antenna he has tried. Once I get the shack rebuilt I intend to take my latest version of Dallas' active dipole there to see if the tighter null will help. I plan on building the WL1030 that RHF mentioned. Martinn Hagg's design look workable. I have major doubts about wide band OpAmps in a harsh RF task, but I am willing to give it a try. I suspect that Dallas' Ultra Linear Amplifier will work as well as the Wellbrook loop maker. And it would be a lot less expensive. The Kiwa amp version 2, should also work. It will need a ?1:! broadband transformer but it is a pretty good amp. The Belrose paper explained why the 2 different heads I have for my McKay-Dymek DA5 behave so differently under temperature extremes. The unit that performs the best under wide, 100F to -20F temperature swings has a slot lengthwise to the hollow center. I have been in a heated conversation with some SWL aquantances here in the central KY area about how long a "long wire" should be. And at what length does it start degrading radio performance. Most SWL or hams, or even professional RF engineers, either don' know, or refuse to think about, the effects too much signal can cause. Front ends and first mixers behave very badly with 1dB to many. I envy DXace becuase he clearly has a superior RF location with a low enough background RF to degrade his R8B. Sadly around here, anything over 100' is more likely to cause problems then help you dig out the really weak DX. Jeff, he lives in a downtown Lexington condo, has had nasty experiences with out of band overload causing all sorts of receiver misbehavoir. And he has an AOR7030, not the plus version. Terry |
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