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Longwire question
Hi from the Netherlands.
Question. I just installed a new longwire antenna. And because I always heard: "'the more wire the better"' I have installed a sort of long U, doubling my regular wire lenght... One end of the U is attatched to an isolator on the first floor and from there it goes down to the garden to another isolator, and from there it goes back up to another isolator. The coax goes to a balun and to my ar3000a and or Kenwood 1000r. The antenna wires don't touch and they are plastic coated. did I do the right thing? seems have a lot of interference.... txs 7373 Joost |
"test" wrote in message ...
I just installed a new longwire antenna. And because I always heard: "'the more wire the better"' I have installed a sort of long U, doubling my regular wire lenght... One end of the U is attatched to an isolator on the first floor and from there it goes down to the garden to another isolator, and from there it goes back up to another isolator. The coax goes to a balun and to my ar3000a and or Kenwood 1000r. The antenna wires don't touch and they are plastic coated. did I do the right thing? seems have a lot of interference.... A balun matches a balanced load (a symmetric antenna such as a dipole) to an unbalanced source (coaxial cable). Does not make any sense to me to feed a longwire via a balun. Maybe you are using an "unun" acting as impedance transformer between 2 unbalanced sides? The increased interference you mention may be caused by overloading your RX, especially if it has no preselector in its front end. Just my 2c worth... |
txs
"Markus L" schreef in bericht ... "test" wrote in message ... I just installed a new longwire antenna. And because I always heard: "'the more wire the better"' I have installed a sort of long U, doubling my regular wire lenght... One end of the U is attatched to an isolator on the first floor and from there it goes down to the garden to another isolator, and from there it goes back up to another isolator. The coax goes to a balun and to my ar3000a and or Kenwood 1000r. The antenna wires don't touch and they are plastic coated. did I do the right thing? seems have a lot of interference.... A balun matches a balanced load (a symmetric antenna such as a dipole) to an unbalanced source (coaxial cable). Does not make any sense to me to feed a longwire via a balun. Maybe you are using an "unun" acting as impedance transformer between 2 unbalanced sides? The increased interference you mention may be caused by overloading your RX, especially if it has no preselector in its front end. Just my 2c worth... |
TEST,
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That's the one I have, an RF Systems Magnetic Longwire Balun (MLB) ..
"RHF" schreef in bericht oups.com... TEST, . Yes - In general the more Wire the Better "Works" to a degree; and your two Shortwave Receivers can handle more wire then most 'portable' AM/FM Shortwave Radios. . What you call a Longwire Antenna is more generally described as a Random Wire Antenna; because it is not 'cut' for one frequency and one or more Wave Lengths (WL) long. . For a Shorwave Listener's (SWL) Random Wire Antenna the 'preferred' lay-out is to have a Long and Elevated Wire Antenna Element that is connected to a Matching Transformer (near ground level) with a Ground Rod and Ground; using a Coax Cable Feed-in-Line to the Radio/Receivers. . READ - The Inverted "L" Antenna - It's 'basic' Lay-Out and Structure The Inverted "L" {Shortwave Listerner's} Antenna - "Why-It-Works" http://groups.yahoo.com/group/Shortw...a/message/1969 http://groups-beta.google.com/group/...b3ddbed819958d . For a Shortwave Listerner's (SWL) Antenna 'bending' the Antenna Wire Element is not a problem. Using Insulated (Plastic Overed) Wire has its Advantages and 'stranded' wire is usually easier to work with then solid. The use of Insulators at the Wire-Ends and other Mounting Points is a 'good' Construction Technique. . READ - Three "Must" Links to Read -wrt- Low Noise SWL Antenna http://groups.yahoo.com/group/Shortw...na/message/949 . READ - "Low Noise Shortwave Listener (SWL) Antenna for most Radio/Receivers" [NO Antenna Tuner Required] http://groups.yahoo.com/group/Shortw...a/message/1525 http://groups.yahoo.com/group/Shortw...a/message/1024 . For most Shortwave Listeners (SWLs) who are considering building and using a Low Noise Inverted "L" Antenna. . READ - Inverted "L' Antenna Reading List http://groups.yahoo.com/group/Shortw...na/message/374 . READ - The 'simple' Answer (in most cases) is the Low Noise Inverted "L" Antenna http://groups.yahoo.com/group/Shortw...a/message/1785 . NOTE - When properly laid-out, arranged and constructed; the Inverted "L" Antenna provides a relatively 'low noise' "Omni-Directional" Shortwave Listener's (SWL) Antenna. . iane ~ RHF . All are WELCOME and "Invited to Join" the Shortwave Listener (SWL) Antenna eGroup on YAHOO ! http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Some Say: On A Clear Day You Can See Forever. http://groups.yahoo.com/group/Shortw...na/message/502 . I BELIEVE: On A Clear Night . . . You Can Hear Forever and Beyond, The BEYOND ! With a Shortwave Listener SWL Antenna of your own making. "If You Build It {SWL Antenna} You Will Hear Them !" . . = = = test wrote: Hi from the Netherlands. Question. I just installed a new longwire antenna. And because I always heard: "'the more wire the better"' I have installed a sort of long U, doubling my regular wire lenght... One end of the U is attatched to an isolator on the first floor and from there it goes down to the garden to another isolator, and from there it goes back up to another isolator. The coax goes to a balun and to my ar3000a and or Kenwood 1000r. The antenna wires don't touch and they are plastic coated. did I do the right thing? seems have a lot of interference.... txs 7373 Joost . |
The more wire up in the air, the more electrical energy will be generated in
it by passing radio waves or waves of any electromagnetic type. You will get more noise, and if your radio isn't sufficiently selective you will have more signals overlapping because they are stronger. The other side of the coin is that you will get more of a weak signal too. The best radioes are able to operate well with weak signals with nearby strong ones without undue interference. A ground may help a lot. A metal rod pounded into the ground is good - keep the length of the wire connecting the receiver to the ground as short as possible. If you have other radioes, tv's computers etc., keep them turned off while you listen. ~~~~~ God gives Peace not war + "Moi" wrote in message ... That's the one I have, an RF Systems Magnetic Longwire Balun (MLB) .. "RHF" schreef in bericht oups.com... TEST, . Yes - In general the more Wire the Better "Works" to a degree; and your two Shortwave Receivers can handle more wire then most 'portable' AM/FM Shortwave Radios. . What you call a Longwire Antenna is more generally described as a Random Wire Antenna; because it is not 'cut' for one frequency and one or more Wave Lengths (WL) long. . For a Shorwave Listener's (SWL) Random Wire Antenna the 'preferred' lay-out is to have a Long and Elevated Wire Antenna Element that is connected to a Matching Transformer (near ground level) with a Ground Rod and Ground; using a Coax Cable Feed-in-Line to the Radio/Receivers. . READ - The Inverted "L" Antenna - It's 'basic' Lay-Out and Structure The Inverted "L" {Shortwave Listerner's} Antenna - "Why-It-Works" http://groups.yahoo.com/group/Shortw...a/message/1969 http://groups-beta.google.com/group/...b3ddbed819958d . For a Shortwave Listerner's (SWL) Antenna 'bending' the Antenna Wire Element is not a problem. Using Insulated (Plastic Overed) Wire has its Advantages and 'stranded' wire is usually easier to work with then solid. The use of Insulators at the Wire-Ends and other Mounting Points is a 'good' Construction Technique. . READ - Three "Must" Links to Read -wrt- Low Noise SWL Antenna http://groups.yahoo.com/group/Shortw...na/message/949 . READ - "Low Noise Shortwave Listener (SWL) Antenna for most Radio/Receivers" [NO Antenna Tuner Required] http://groups.yahoo.com/group/Shortw...a/message/1525 http://groups.yahoo.com/group/Shortw...a/message/1024 . For most Shortwave Listeners (SWLs) who are considering building and using a Low Noise Inverted "L" Antenna. . READ - Inverted "L' Antenna Reading List http://groups.yahoo.com/group/Shortw...na/message/374 . READ - The 'simple' Answer (in most cases) is the Low Noise Inverted "L" Antenna http://groups.yahoo.com/group/Shortw...a/message/1785 . NOTE - When properly laid-out, arranged and constructed; the Inverted "L" Antenna provides a relatively 'low noise' "Omni-Directional" Shortwave Listener's (SWL) Antenna. . iane ~ RHF . All are WELCOME and "Invited to Join" the Shortwave Listener (SWL) Antenna eGroup on YAHOO ! http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Some Say: On A Clear Day You Can See Forever. http://groups.yahoo.com/group/Shortw...na/message/502 . I BELIEVE: On A Clear Night . . . You Can Hear Forever and Beyond, The BEYOND ! With a Shortwave Listener SWL Antenna of your own making. "If You Build It {SWL Antenna} You Will Hear Them !" . . = = = test wrote: Hi from the Netherlands. Question. I just installed a new longwire antenna. And because I always heard: "'the more wire the better"' I have installed a sort of long U, doubling my regular wire lenght... One end of the U is attatched to an isolator on the first floor and from there it goes down to the garden to another isolator, and from there it goes back up to another isolator. The coax goes to a balun and to my ar3000a and or Kenwood 1000r. The antenna wires don't touch and they are plastic coated. did I do the right thing? seems have a lot of interference.... txs 7373 Joost . |
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"mongo" wrote in message ... http://www.universal-radio.com/catalog/antsup/1484.html I don't see a ground lead on that one. How does one ground it? |
SANJAYA,
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in reality the longer the wire the better.
But there is a down side the longer the wire the more you receive including interference. you could try useing an Antenna Tuner preselector... "RHF" wrote in message oups.com... TEST, . Yes - In general the more Wire the Better "Works" to a degree; and your two Shortwave Receivers can handle more wire then most 'portable' AM/FM Shortwave Radios. . What you call a Longwire Antenna is more generally described as a Random Wire Antenna; because it is not 'cut' for one frequency and one or more Wave Lengths (WL) long. . For a Shorwave Listener's (SWL) Random Wire Antenna the 'preferred' lay-out is to have a Long and Elevated Wire Antenna Element that is connected to a Matching Transformer (near ground level) with a Ground Rod and Ground; using a Coax Cable Feed-in-Line to the Radio/Receivers. . READ - The Inverted "L" Antenna - It's 'basic' Lay-Out and Structure The Inverted "L" {Shortwave Listerner's} Antenna - "Why-It-Works" http://groups.yahoo.com/group/Shortw...a/message/1969 http://groups-beta.google.com/group/...b3ddbed819958d . For a Shortwave Listerner's (SWL) Antenna 'bending' the Antenna Wire Element is not a problem. Using Insulated (Plastic Overed) Wire has its Advantages and 'stranded' wire is usually easier to work with then solid. The use of Insulators at the Wire-Ends and other Mounting Points is a 'good' Construction Technique. . READ - Three "Must" Links to Read -wrt- Low Noise SWL Antenna http://groups.yahoo.com/group/Shortw...na/message/949 . READ - "Low Noise Shortwave Listener (SWL) Antenna for most Radio/Receivers" [NO Antenna Tuner Required] http://groups.yahoo.com/group/Shortw...a/message/1525 http://groups.yahoo.com/group/Shortw...a/message/1024 . For most Shortwave Listeners (SWLs) who are considering building and using a Low Noise Inverted "L" Antenna. . READ - Inverted "L' Antenna Reading List http://groups.yahoo.com/group/Shortw...na/message/374 . READ - The 'simple' Answer (in most cases) is the Low Noise Inverted "L" Antenna http://groups.yahoo.com/group/Shortw...a/message/1785 . NOTE - When properly laid-out, arranged and constructed; the Inverted "L" Antenna provides a relatively 'low noise' "Omni-Directional" Shortwave Listener's (SWL) Antenna. . iane ~ RHF . All are WELCOME and "Invited to Join" the Shortwave Listener (SWL) Antenna eGroup on YAHOO ! http://groups.yahoo.com/group/Shortwave-SWL-Antenna/ . Some Say: On A Clear Day You Can See Forever. http://groups.yahoo.com/group/Shortw...na/message/502 . I BELIEVE: On A Clear Night . . . You Can Hear Forever and Beyond, The BEYOND ! With a Shortwave Listener SWL Antenna of your own making. "If You Build It {SWL Antenna} You Will Hear Them !" . . = = = test wrote: Hi from the Netherlands. Question. I just installed a new longwire antenna. And because I always heard: "'the more wire the better"' I have installed a sort of long U, doubling my regular wire lenght... One end of the U is attatched to an isolator on the first floor and from there it goes down to the garden to another isolator, and from there it goes back up to another isolator. The coax goes to a balun and to my ar3000a and or Kenwood 1000r. The antenna wires don't touch and they are plastic coated. did I do the right thing? seems have a lot of interference.... txs 7373 Joost . |
"big boy now" in reality the longer the wire the better. But there is a down side the longer the wire the more you receive including interference. you could try useing an Antenna Tuner preselector... Then how would you explain the performance equivalency of a 2Xwavelength horizontal loop's performance to that of a 1/2wave dipole cut for same frequency? http://www.cebik.com/wire/horloop.html The advantage of this type of loop is that it performs equally to a dipole on multiple frequencies. It is an excellent SWL antenna if you have the real-estate. Even a 1Xwavelength H-loop performs very well. |
tianli_ wrote:
http://www.cebik.com/wire/horloop.html The advantage of this type of loop is that it performs equally to a dipole on multiple frequencies. The main disadvantage is that you could buy several hundred better performing antennas for less than the first year's property taxes for the land needed to construct the damn thing! Yeesh. This makes my jokes about a 30-element MW log-periodic sound practical by comparison. |
Pull out your calculator. It's not that big.
"clifto" wrote in message ... tianli_ wrote: http://www.cebik.com/wire/horloop.html The advantage of this type of loop is that it performs equally to a dipole on multiple frequencies. The main disadvantage is that you could buy several hundred better performing antennas for less than the first year's property taxes for the land needed to construct the damn thing! Yeesh. This makes my jokes about a 30-element MW log-periodic sound practical by comparison. |
CW wrote:
"clifto" wrote... tianli_ wrote: http://www.cebik.com/wire/horloop.html The advantage of this type of loop is that it performs equally to a dipole on multiple frequencies. Yeesh. This makes my jokes about a 30-element MW log-periodic sound practical by comparison. Pull out your calculator. It's not that big. Imagine my surprise when my MW loop turned out to be only 1341 feet in diameter, needing only 33 acres to hold it (41-1/3 if you own the entire square the circle is inscribed in). We'd need about 36 poles to hold it half a wavelength, or 1,054 feet, off the ground. Maybe we could rent Arecibo... is it big enough? |
Imagine my surprise when my MW loop turned out to be only 1341 feet in
diameter, needing only 33 acres to hold it (41-1/3 if you own the entire square the circle is inscribed in). We'd need about 36 poles to hold it half a wavelength, or 1,054 feet, off the ground. Maybe we could rent Arecibo... is it big enough? I don't think anyone is going to go through the trouble of building a H-loop for the MW BCB. The original post inquired about the feasibility of a longwire shaped into a "U". He was almost there by a few yards short of a better performing horizontal loop. The point of the discussion, and the links I included, show that a modest horizontal loop has the same dB gain as a dipole AT THE SAME HEIGHT. The loop advantage is that the dipole performs optimally on its fundamental and harmonics ONLY, while the H-Loop performs equally well on all frequencies at and above about its one wavelength circumference. Read the links and learn. |
JD,
From what you have written here; I soumds like you built yourself a SkyWire Loop Antenna. |
Except at Art Bell's compound.
On Sat, 26 Feb 2005 16:06:57 -0500, "Jack Painter" wrote: "tianli_" wrote The point of the discussion, and the links I included, show that a modest horizontal loop has the same dB gain as a dipole AT THE SAME HEIGHT. The loop advantage is that the dipole performs optimally on its fundamental and harmonics ONLY, while the H-Loop performs equally well on all frequencies at and above about its one wavelength circumference. Well said. A horizontal dipole is optimal only between 1/4 wave to preferably 1/2 wave height above ground. Anyone who thinks erecting a horizontal loop at 1/2 wave height is easy, we've got a bridge in Arizona to sell you. These horizontal loops are used, but they are typically strung between the tops of several tall telephone poles erected in a circle. Nothing you see in a hobbyists backyard. Jack |
Nice jd!
Many folks here are missing the point. It doesn't have to be 2X wavelength or even 1X wavelength. Just string up a horiz. loop anywhere you can and as long as you can make it. Don't worry about height above ground or if it is in a circular, square or trapezoid, or what have you, configuration. If it is anywhere near as high as your proposed longwire or dipole it will work just as well but over a much broader swath of frequencies. Think of its performance as much like a discone antenna at VHF & UHF - no gain over a half-wave vertical but very broadbanded. The H-loop "generally" has omni-directional characteristics where as a dipole or longwire has definite nulls and peaks around the compass. I would guess that my H-loop is about at least 70-75 meters in circumference at an average height of about 20 ft. It is strung around the edge of my roof in a large "L" configuration with the wire tucked under the roofing shingles at strategic locations - invisible! It has survived several seasons of severe weather and hasn't budged. I use it for SWLing as well as transmitting on 80-10 meters using a vintage Johnson Matchbox - sweet! Compared to a dipole or a longwire it doesn't experience those "dips" in reception on certain bands. Any "dips" that do occur are not as deep and an antenna matchbox will easily make up for it. Where anyone obtained the idea you must use dozens of 75+ ft telephone poles around 100 acres of real-estate has simply never built or used a horiz. loop. Granted, it would undoubtedly work better at greater height, my horizontal loop encircles a small section of my woods at varying heights of anywhere from 6 feet to (maybe) 15 feet. I ran about 475 to 500 feet of wire, hanging it off available tree branches as I went, in what is more or less a square with somewhat bulging sides. I couldn't tell you exactly how much wire I used, other than I used enough to form a loop through the woods. I couldn't tell you it's impedance. I feed it with coax through a home-made 1:1 transformer. I have no complaints with it's performance. I think there's this expectation by folks new to the hobby that everything has to be "labratory" perfect or it's a waste of time. In my experience, I have found that wire antenna's are *very* forgiving of imperfections. Granted, they will not perform as well as something carefully constructed in a labratory environment, but they will *still* work - and there's even odds (or better than even) they will work better than expected! My rule of thumb is: "As much wire as you reasonably can, as high as you reasonably can." In different situations, that could be 30 feet of wire at house-eave level -or- a 2wl horizontal loop at 1wl above dirt. Just do what you can, and are interested in trying, and don't sweat the details until *after* you establish a baseline. -=jd=- -- My Current Disposable Email: (Remove YOUR HAT to reply directly) |
"tianli_" (and jd) wrote in message ... Nice jd! (( Comments inserted between text )) Many folks here are missing the point. It doesn't have to be 2X wavelength or even 1X wavelength. Just string up a horiz. loop anywhere you can and as long as you can make it. Don't worry about height above ground or if it is in a circular, square or trapezoid, or what have you, configuration. If it is anywhere near as high as your proposed longwire or dipole it will work just as well but over a much broader swath of frequencies. Think of its performance as much like a discone antenna at VHF & UHF - no gain over a half-wave vertical but very broadbanded. The H-loop "generally" has omni-directional characteristics where as a dipole or longwire has definite nulls and peaks around the compass. I would guess that my H-loop is about at least 70-75 meters in circumference at an average height of about 20 ft. It is strung around the edge of my roof in a large "L" configuration with the wire tucked under the roofing shingles at strategic locations - invisible! It has survived several seasons of severe weather and hasn't budged. I use it for SWLing as well as transmitting on 80-10 meters using a vintage Johnson Matchbox - sweet! -- While it sounds like you have little more than a cloud warmer there (if otherwise please do advise), you're right that it costs very little to run a few hundred feet of wire anywhere you can get it. The result could be a good listening antenna. What it won't normally be is a good transmitter, unless it meets mimimum design conditions. Also, don't you worry what kind of RF you illuminate the house with? It looks to me like people inside could be as close as 2 or 3' from your antenna, and at most HF frequencies that is way too close to 100+w transmit power. -- Compared to a dipole or a longwire it doesn't experience those "dips" in reception on certain bands. Any "dips" that do occur are not as deep and an antenna matchbox will easily make up for it. Where anyone obtained the idea you must use dozens of 75+ ft telephone poles around 100 acres of real-estate has simply never built or used a horiz. loop. -- That would be me. I have seen one in use, just never replicated by a hobbyist (yet). Without the near 1/2 wave design-elevation, a horizontal wire antenna becomes NVIS (or cloud warmer). We've all heard of people doing this with their rain gutters for years, but that doesn't translate to a worthwhile effort when compared to most achievable antenna designs. -- Granted, it would undoubtedly work better at greater height, my horizontal loop encircles a small section of my woods at varying heights of anywhere from 6 feet to (maybe) 15 feet. I ran about 475 to 500 feet of wire, hanging it off available tree branches as I went, in what is more or less a square with somewhat bulging sides. I couldn't tell you exactly how much wire I used, other than I used enough to form a loop through the woods. I couldn't tell you it's impedance. I feed it with coax through a home-made 1:1 transformer. I have no complaints with it's performance. I think there's this expectation by folks new to the hobby that everything has to be "labratory" perfect or it's a waste of time. In my experience, I have found that wire antenna's are *very* forgiving of imperfections. Granted, they will not perform as well as something carefully constructed in a labratory environment, but they will *still* work - and there's even odds (or better than even) they will work better than expected! My rule of thumb is: "As much wire as you reasonably can, as high as you reasonably can." In different situations, that could be 30 feet of wire at house-eave level -or- a 2wl horizontal loop at 1wl above dirt. Just do what you can, and are interested in trying, and don't sweat the details until *after* you establish a baseline. -=jd=- True enough. Jack |
"-=jd=-" wrote /snip For now, I have no interest in talking. Though, I have often thought of working towards the General ticket just to see if I could pass the tests, simply out of personal curiosity. -=jd=- I couldn't memorize 1 wpm of Morse code in the Boy Scouts, doubt that it is going to happen 35 years later ;-) I'm on the air for the USCG and they don't care if we know code or not. A smaller and smaller number of older chiefs and officers who were hams for a hundred years still know code in the guard - not much interest in it or radio in general by younger generations, even when they operate them for a living. Computer networking is what drives the communication business today, the radios themselves seem a small, mostly forgotten part of it. Sorry to have gotten off-topic with the longwire - for listening it is certainly the most forgiving of any configuration imaginable. Jack |
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