"Joe Strain" wrote in message om... The currrent in the wire produces an electromagnetic field which has a defined radius. The field coil of a motor is used to turn it into a magnet so the motor will work...stretch out the windings, no emf imposed upon the core..no magnet-action-no work Stretch it out, you exceed the radius of the electromagnetic field, no interaction, no function. The whole purpose of the antenna in coil-structure is to use the induced emf to create a load on the antenna so it "thinks" it is longer Yodar Read this a couple days ago, and am still trying to wrap my brain around it. Will try to reply in more depth 12/25 or 12/26 Dave "Dave" wrote in message ... I just got through picking up a ton of discontinued wire from my local Home Depot, and was planning on building a "broomstick" antenna like some I found described on the net. Got a question though: doesn't "stretching out" the coil to a meter or more reduce the inductance of the resulting coil? Why wouldn't it work better to just leave it on the spool? I was under the impression that the formula for calculating the inductance for a given coil involved multiplying the square of the number of coils by the ratio of the coil width to length. Wouldn't this mean that a "longer" coil would have a lower inductance than a "shorter" coil, given the same length of wire and approximate diameter of coils? Forgive me if I'm being stupid here, it has been twenty years since I have attempted anything like this, but that was what I thought. The main account I am thinking of was related by someone in Saudi Arabia who wrapped 1.2 kM of wire around a piece of PVC and vastly improved their reception of WWV in the states. I was going to do something similar, and then looked at the two spools of wire that I was about to unwrap. They are already coils, so shouldn't I be able to just hook them up to an aligator clip and stick this to my whip antenna? (I am now thinking about taking the wire off of the smaller spool and adding it to the larger. Shouldn't that work?) And if I leave the wire on the spools (which are plastic) couldn't I turn them toward or away from the station of interest to further improve reception? (I could even put this in my attic, gaining a few feet of elevation and hiding it from my unappreciative wife.) Any input on any part of this idea is more than welcome. I would greaty value the opinions of those who have actually done something like one of these two options. Thanks, Dave |
Thanks for the links. The website for the first four was where I got my
original information, but I couldn't remember where it was. I appreciate it. Thanks also for hte Yahoo link. I'm going to check that out. Dave "RHF" wrote in message om... DAVE, Concerning the BroomStick Antenna: http://www.hard-core-dx.com/nordicdx.../bromstik.html http://www.hard-core-dx.com/nordicdx...al/broom2.html http://www.hard-core-dx.com/nordicdx.../tunestik.html http://www.hard-core-dx.com/nordicdx.../tunstik2.html IIRC: The 1.2kM of wire was wrapped on a piece of PVC Pipe http://www.hard-core-dx.com/nordicdx...al/broom3.html - - - "improved model is 6 m (18Ft) of 4 Inch OD PVC" (Section of Well Lining that was over 18 Foot Long.) = = = Effectively a 18 Foot Vertical Antenna. "I mounted the 6 m (18Ft) portion vertically, and the 2.5 m (7.5 Ft) section horizontally (a "reverted "L"" system). I added in my 250 m (750 Ft) Random Long Wire (it was there, so why not use it?), grounded the thing and in great anticipation, plugged it into the radio. - - - The results were more than amazing." - by Marty Leipzig HELLO! Forget the BroomStick [.] TBL: This Guy had a 750 Ft Random Wire Antenna ! When your 'think' of a Broom Stick Antenna that has a size small wire tightly wrapped along a length of PVC Pipe. Just consider the piece of PVC Pipe an equal section of Aluminum Tubing; and not much more. Better to try a Eight Foot Section of 2"-3" PVC Pipe with a single wire wrapped in three coils on it. * Use a 500 Foot Spool of #14 AWG Insulated 19 Stranded Wire. * Each "Coil" set to resonate at a different band of your choice. * Each "Coil" spaced 1'-2' apart on the PVC Pipe. IMHO: The BrommStick Antenna is a 'good idea' for Apartment Residents stuck with a single outside facing window. - - - Been There, Done That ! REMEMBER: The ANTENNA + GROUND SYSTEM is . . . 55.5% of the Radio/Receiver and Antenna+Ground Reception Equation. GoTo= http://groups.yahoo.com/group/SWL-AM...na/message/288 All are WELCOME at this "Antenna Ashram" + Who Seek Better Reception + + And a Clear Understanding + + + From That Which Transcends the Ether and Beyond. WHE "SWL Antennas and AM & FM Antennas" eGroup on YAHOO ! - When You NEED to Contemplate the - - "Aerial High" and the - - - "True Meaning of Ground". iane ~ RHF . . = = = "Dave" = = = wrote in message ... I just got through picking up a ton of discontinued wire from my local Home Depot, and was planning on building a "broomstick" antenna like some I found described on the net. Got a question though: doesn't "stretching out" the coil to a meter or more reduce the inductance of the resulting coil? Why wouldn't it work better to just leave it on the spool? I was under the impression that the formula for calculating the inductance for a given coil involved multiplying the square of the number of coils by the ratio of the coil width to length. Wouldn't this mean that a "longer" coil would have a lower inductance than a "shorter" coil, given the same length of wire and approximate diameter of coils? Forgive me if I'm being stupid here, it has been twenty years since I have attempted anything like this, but that was what I thought. The main account I am thinking of was related by someone in Saudi Arabia who wrapped 1.2 kM of wire around a piece of PVC and vastly improved their reception of WWV in the states. I was going to do something similar, and then looked at the two spools of wire that I was about to unwrap. They are already coils, so shouldn't I be able to just hook them up to an aligator clip and stick this to my whip antenna? (I am now thinking about taking the wire off of the smaller spool and adding it to the larger. Shouldn't that work?) And if I leave the wire on the spools (which are plastic) couldn't I turn them toward or away from the station of interest to further improve reception? (I could even put this in my attic, gaining a few feet of elevation and hiding it from my unappreciative wife.) Any input on any part of this idea is more than welcome. I would greaty value the opinions of those who have actually done something like one of these two options. Thanks, Dave . |
"Telamon" wrote in message ... In article , "Dale Parfitt" wrote: "donutbandit" wrote in message ... "Dave" wrote in : I just got through picking up a ton of discontinued wire from my local Home Depot, and was planning on building a "broomstick" antenna like some I found described on the net. I built one. I was quite disappointed after reading all the hype. I get better reception from a wire run around the corners of my bedroom ceiling. I would not anticipate the broomstick antenna to be any different than a metal tube or rod of similar dimensions. Good comparison. A tightly wound broomstick would resemble a rod for receiving purposes. -- Telamon Ventura, California Still true, even if each turn of wire is insulated from those adjacent to it? How could that be? Thanks, Dave |
"Dave" wrote in message ... The roof is wood with asphalt shingles. But the attic is only about three feet tall (see my reply to diverd4777). With extreme difficulty one can get from one side of the house to the other through the attic, but trying to do this while carrying something is next to impossible. Is that what you are asking about, about the crown? Height, in the attic? If not please let me know. The crown of the roof is the pointed top (outside). ^ === crown / \ | | |
Dave wrote:
It is a metal fence. Chain-link. I didn't think that was a very likely answer to my problems. I'd be curious as to why running a wire along a metal fence would be such a problem. I just ran about 200 feet of wire along the top of a wire fence (2 inch square openings), albeit the type that is covered with some green vinyl. And I have noticed CONSIDERABLE improvement in reception. Wouldn't attaching to so much metal just help to expand the range of the antenna? Also, related to the metal fence thing: what would happen were I to attach a wire to my metal roof? And as long as we're on the subject of random wire, what's the deal with needing "stranded" wire. I had about 100 feet of that first, and then when I went to buy some more all they had was single strand, so I bought that and just added that to the end of the stranded. what's the importance/need of using stranded? av |
AV wrote: Dave wrote: It is a metal fence. Chain-link. I didn't think that was a very likely answer to my problems. I'd be curious as to why running a wire along a metal fence would be such a problem. I just ran about 200 feet of wire along the top of a wire fence (2 inch square openings), albeit the type that is covered with some green vinyl. And I have noticed CONSIDERABLE improvement in reception. Wouldn't attaching to so much metal just help to expand the range of the antenna? Also, related to the metal fence thing: what would happen were I to attach a wire to my metal roof? And as long as we're on the subject of random wire, what's the deal with needing "stranded" wire. I had about 100 feet of that first, and then when I went to buy some more all they had was single strand, so I bought that and just added that to the end of the stranded. what's the importance/need of using stranded? av As far as ability to pick up RF signal, I'm not aware that there *is* a bit of difference. Stranded is a bit stronger, perhaps, but if anyone ever told you you "had" to use stranded for antenna wire, I'd be intersted in hearing their justification for that. Tony ----== Posted via Newsfeed.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeed.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= 19 East/West-Coast Specialized Servers - Total Privacy via Encryption =--- |
TM,
Antennas - WHY - Stranded Wire is a 'little' Better. 1. More Flexible and Less Breakage. 2. If you use a Single Strand (1) type Wire. When the One Strand Breaks the Wire Has Failed. 3. If you use a Multi-Stranded (19) type Wire. When the One to Three Strands Breaks the Wire Has NOT Failed; and you still have a Wire that would be rated at about 85%. NOTE: Nineteen Stranded Wire has a Single Strand; that is Surounded by Six Strands (Optimum Re-inforcement); that is Surounded by Twelve Strands (Optimum Re-inforcement); {Like A Bridge Support Cable} Then Covered by Insulation. 4. IIRC: For the same AWG Size Wire the Stranded Wire is Rated as Stronger and Lighter then the Single Strand Wire. 5. RF Wise - Multi-Strand Wire has more Surface Area for RF to Travel On. So specialty Antenna Wires like * "QuietFlex" (41 Strand @ #14 AWG) * "Flex-Weave" (168 Strands @ #14 AWG) Can Actually (In-Fact) make a' difference' in your Reception. ? NOW ? IS ? ANY ? OF ? THIS ? TRUE ? REMEMBER: The Antenna & Ground System is 55.5% of the Radio/Receiver and Antenna/Ground Reception Equation. http://groups.yahoo.com/group/SWL-AM...na/message/288 WHE "SWL Antennas and AM & FM Antennas" eGroup on YAHOO ! - When You NEED to Contemplate the - - "Aerial High" and the - - - "True Meaning of Ground". iane ~ RHF All are WELCOME at this "Antenna Ashram" + Who Seek Better Reception + + And a Clear Understanding + + + From That Which Transcends the Ether and Beyond. .. .. = = = Tony Meloche = = = wrote in message ... AV wrote: Dave wrote: It is a metal fence. Chain-link. I didn't think that was a very likely answer to my problems. I'd be curious as to why running a wire along a metal fence would be such a problem. I just ran about 200 feet of wire along the top of a wire fence (2 inch square openings), albeit the type that is covered with some green vinyl. And I have noticed CONSIDERABLE improvement in reception. Wouldn't attaching to so much metal just help to expand the range of the antenna? Also, related to the metal fence thing: what would happen were I to attach a wire to my metal roof? And as long as we're on the subject of random wire, what's the deal with needing "stranded" wire. I had about 100 feet of that first, and then when I went to buy some more all they had was single strand, so I bought that and just added that to the end of the stranded. what's the importance/need of using stranded? av As far as ability to pick up RF signal, I'm not aware that there *is* a bit of difference. Stranded is a bit stronger, perhaps, but if anyone ever told you you "had" to use stranded for antenna wire, I'd be intersted in hearing their justification for that. Tony .. |
RHF wrote:
? NOW ? IS ? ANY ? OF ? THIS ? TRUE ? . sounds pretty plausible to me, but then i'm the one who asked the question, and i'm a fairly gullible person. as for the strength question, multi-strand didn't withstand an avalanche of snow coming off the roof and breaking it, nor did it withstand my puppy biting it into a few pieces. i kinda doubt there is really too much difference in strength. the fact that stranded allows for the breakage of one strand while leaving the others intact, but just the same, those single threads are thinner and more likely to break in the first place! as for surface area, that sounds plausible, but then that brings it back to the metal fence question. if it's surface area you want, then why the warning not to lay a random wire along a metal fence. wouldn't the fence be helpful in reception and pass things along into the wire? av |
DAVE,
Understanding the "BroomStick" Antenna and its Coil. = WHY = Three Shorter Coils may Work Better then One Long Coil. First: Lets take a Eight Foot (8Ft) piece of One Inch (1") Outside Diameter (OD) PVC Pipe. (This is our BroomStick Antenna "FORM".) Second: Take a Single piece of #14 AWG Stranded Insulated Wire and stretch it out along the length of the PVC Pipe. What Do We Have? A Vertical Antenna Element - That happens to be 1/4 of a Wave Length (WL) in the range of 31 MHz. Third: Take a Single piece of #14 AWG Stranded Insulated Wire and stretch it out along the length of the PVC Pipe and form a Coil of 11 Turns (about 1") at the Bottom. What Do We Have? A "LOADED" Vertical Antenna Element - That happens to act like 1/4 of a Wave Length (WL) in the range of 10 MHz. Fourth: Take a Single piece of #14 AWG Stranded Insulated Wire and stretch it out along the length of the PVC Pipe and form a Coil of 66 Turns (about 6") at the Bottom. What Do We Have? A "LOADED" Vertical Antenna Element - That happens to act like 1/4 of a Wave Length (WL) in the range of 1 MHz. Fifth: Take a Single piece of #14 AWG Stranded Insulated Wire and stretch it out along the length of the PVC Pipe and form a Coil of 460 Turns (about 2Ft) at the Bottom. What Do We Have? A "LOADED" Vertical Antenna Element - That happens to act like 1/4 of a Wave Length (WL) for about 100 kHz. CONCLUSION: The Conclusion That We Must Draw From The Above Is: That the common BroomStick Antenna that has wire closely wound on a piece of PVC Pipe to FORM a Coil of 3Ft, 5Ft, or all of the 8Ft; must be resonant well below 100 kHz. THEREFO Therefore for 31 MHz, 10 MHz, 1MHz and anything in-between: The BroomStick Antenna simply looks effectively like a 1/4 WL Antenna Element that works so-so in the range of 31 MHz. = = = Effectively like a 1" Copper Pipe. BETTER: The Better Alternative is to Start over by taking a Eight Foot (8Ft) piece of One Inch (1") Outside Diameter (OD) PVC Pipe. (This is our BroomStick Antenna "FORM".) Next, take a single piece of #14 AWG Stranded Insulated Wire and wrap three coils on the PVC Pipe. * "Concerning the BroomStick Antenna" Read Message #410 GoTo= http://groups.yahoo.com/group/SWL-AM...na/message/410 * "Image of Tri-Band 'BroomStick' Antenna" GoTo= http://groups.yahoo.com/group/SWL-AM...na/message/412 PHOTOS Section: Image "BroomStick Antenna Tri-Band" GoTo= http://photos.groups.yahoo.com/group...FM-Antenna/lst iane ~ RHF .. .. = = = "Dave" = = = wrote in message ... "Telamon" wrote in message ... In article , "Dale Parfitt" wrote: "donutbandit" wrote in message ... "Dave" wrote in : I just got through picking up a ton of discontinued wire from my local Home Depot, and was planning on building a "broomstick" antenna like some I found described on the net. I built one. I was quite disappointed after reading all the hype. I get better reception from a wire run around the corners of my bedroom ceiling. I would not anticipate the broomstick antenna to be any different than a metal tube or rod of similar dimensions. Good comparison. A tightly wound broomstick would resemble a rod for receiving purposes. -- Telamon Ventura, California - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Still true, even if each turn of wire is insulated from those adjacent to it? How could that be? Thanks, Dave .. |
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