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Can you ID this antenna
The other day, while passing the local Reserves building, I noticed a
new antenna mounted to their tower. It was in an inverted Vee form but had approximately three white insulators that were around 6 to 8 inches in length running between the two wires of this antenna. The antenna was fed, via coax, from the bottom by what appeared to be a balun. The wire proceeded out from the balun past the bottom of the three (per side) insulators and at each end appeared to either double back, upon itself, or be attached to the top wire which was connected to the bottom wire at each end then passed through the top of each of the three (per side) insulators and ended up meeting the other sides, top wire, at, what appeared to be, a plastic mounting plate that served as a fastening point for each of the top wires and also as a top support for the antenna's middle to be connected via rope, wire, etc to either a tower or mast. The top (middle) of the antenna had no contact with the bottom middle (of the antenna), where it was fed from, but the top and bottom wires (isolated from each other as it ran from the middle to end, by three white insulators approx 6-8 inches in length) The only contact of the top wire to the bottom wire was at the extreme ends of this inverted vee type antenna where the top and bottom wires were attached to each other then each end mounted, via insulator, to some connecting point to support the height of the ends of this antenna. I've just never seen this type antenna and would love to build one. If you know the type, from the description I have given, please share the name of it and where I might be able to obtain the forumulas for calculating length. What bands does it work? Is it homebrew or commercial? Any input would be appreciated. |
Can you ID this antenna
On Jun 22, 8:11*am, Gary KW4Z wrote:
The other day, while passing the local Reserves building, I noticed a new antenna mounted to their tower. *It was in an inverted Vee form but had approximately three white insulators that were around 6 to 8 inches in length running between the two wires of this antenna. *The antenna was fed, via coax, from the bottom by what appeared to be a balun. *The wire proceeded out from the balun past the bottom of the three (per side) insulators and at each end appeared to either double back, upon itself, or be attached to the top wire which was connected to the bottom wire at each end then passed through the top of each of the three (per side) insulators and ended up meeting the other sides, top wire, at, what appeared to be, a plastic mounting plate that served as a fastening point for each of the top wires and also as a top support for the antenna's middle to be connected via rope, wire, etc to either a tower or mast. *The top (middle) of the antenna had no contact with the bottom middle (of the antenna), where it was fed from, but the top and bottom wires (isolated from each other as it ran from the middle to end, by three white insulators approx 6-8 inches in length) *The only contact of the top wire to the bottom wire was at the extreme ends of this inverted vee type antenna where the top and bottom wires were attached to each other then each end mounted, via insulator, to some connecting point to support the height of the ends of this antenna. I've just never seen this type antenna and would love to build one. If you know the type, from the description I have given, please share the name of it and where I might be able to obtain the forumulas for calculating length. What bands does it work? *Is it homebrew or commercial? Any input would *be appreciated. Totally lost in the discription, Can you supply a picture. |
Can you ID this antenna
On Jun 22, 8:20*am, JIMMIE wrote:
On Jun 22, 8:11*am, Gary KW4Z wrote: The other day, while passing the local Reserves building, I noticed a new antenna mounted to their tower. *It was in an inverted Vee form but had approximately three white insulators that were around 6 to 8 inches in length running between the two wires of this antenna. *The antenna was fed, via coax, from the bottom by what appeared to be a balun. *The wire proceeded out from the balun past the bottom of the three (per side) insulators and at each end appeared to either double back, upon itself, or be attached to the top wire which was connected to the bottom wire at each end then passed through the top of each of the three (per side) insulators and ended up meeting the other sides, top wire, at, what appeared to be, a plastic mounting plate that served as a fastening point for each of the top wires and also as a top support for the antenna's middle to be connected via rope, wire, etc to either a tower or mast. *The top (middle) of the antenna had no contact with the bottom middle (of the antenna), where it was fed from, but the top and bottom wires (isolated from each other as it ran from the middle to end, by three white insulators approx 6-8 inches in length) *The only contact of the top wire to the bottom wire was at the extreme ends of this inverted vee type antenna where the top and bottom wires were attached to each other then each end mounted, via insulator, to some connecting point to support the height of the ends of this antenna. I've just never seen this type antenna and would love to build one. If you know the type, from the description I have given, please share the name of it and where I might be able to obtain the forumulas for calculating length. What bands does it work? *Is it homebrew or commercial? Any input would *be appreciated. Totally lost in the discription, Can you supply a picture.- Hide quoted text - - Show quoted text - Maybe an orthogonal antenna. |
Can you ID this antenna
"Gary KW4Z" wrote in message ... The other day, while passing the local Reserves building, I noticed a new antenna mounted to their tower. It was in an inverted Vee form but had approximately three white insulators that were around 6 to 8 inches in length running between the two wires of this antenna. The antenna was fed, via coax, from the bottom by what appeared to be a balun. The wire proceeded out from the balun past the bottom of the three (per side) insulators and at each end appeared to either double back, upon itself, or be attached to the top wire which was connected to the bottom wire at each end then passed through the top of each of the three (per side) insulators and ended up meeting the other sides, top wire, at, what appeared to be, a plastic mounting plate that served as a fastening point for each of the top wires and also as a top support for the antenna's middle to be connected via rope, wire, etc to either a tower or mast. The top (middle) of the antenna had no contact with the bottom middle (of the antenna), where it was fed from, but the top and bottom wires (isolated from each other as it ran from the middle to end, by three white insulators approx 6-8 inches in length) The only contact of the top wire to the bottom wire was at the extreme ends of this inverted vee type antenna where the top and bottom wires were attached to each other then each end mounted, via insulator, to some connecting point to support the height of the ends of this antenna. I've just never seen this type antenna and would love to build one. If you know the type, from the description I have given, please share the name of it and where I might be able to obtain the forumulas for calculating length. What bands does it work? Is it homebrew or commercial? Any input would be appreciated. Sounds very much like B&W's "folded dipole". I use quotes because in their version they have a resistor at the center of the unfed wire that absorbs power and smooths out the VSWR. http://www.bwantennas.com/ama/amaindex.htm Dale W4OP |
Can you ID this antenna
On Jun 22, 8:07*am, "Dale Parfitt" wrote:
"Gary KW4Z" wrote in message ... The other day, while passing the local Reserves building, I noticed a new antenna mounted to their tower. *It was in an inverted Vee form but had approximately three white insulators that were around 6 to 8 inches in length running between the two wires of this antenna. *The antenna was fed, via coax, from the bottom by what appeared to be a balun. *The wire proceeded out from the balun past the bottom of the three (per side) insulators and at each end appeared to either double back, upon itself, or be attached to the top wire which was connected to the bottom wire at each end then passed through the top of each of the three (per side) insulators and ended up meeting the other sides, top wire, at, what appeared to be, a plastic mounting plate that served as a fastening point for each of the top wires and also as a top support for the antenna's middle to be connected via rope, wire, etc to either a tower or mast. *The top (middle) of the antenna had no contact with the bottom middle (of the antenna), where it was fed from, but the top and bottom wires (isolated from each other as it ran from the middle to end, by three white insulators approx 6-8 inches in length) *The only contact of the top wire to the bottom wire was at the extreme ends of this inverted vee type antenna where the top and bottom wires were attached to each other then each end mounted, via insulator, to some connecting point to support the height of the ends of this antenna. I've just never seen this type antenna and would love to build one. If you know the type, from the description I have given, please share the name of it and where I might be able to obtain the forumulas for calculating length. What bands does it work? *Is it homebrew or commercial? Any input would *be appreciated. Sounds very much like B&W's "folded dipole". I use quotes because in their version they have a resistor *at the center of the unfed wire that absorbs power and smooths out the VSWR.http://www.bwantennas.com/ama/amaindex.htm Dale W4OP Dale, Though not exactly like the B&W antenna that you linked to it is similar enough that I feel it has to be based upon that antenna design. Jimmie, I'm sorry I totally lost you in the description. I'll see if I can get a photo however all of you are aware of the security precautions since Sept 11. My apology if the description was not concise enough to enable you to identify. |
Can you ID this antenna
The B&W, which comes in several configuations, is a pretty standard
military antenna. We had several of them on various buildings at Ft. Meade, where I worked and I've seen them on military posts all over. Several other commands at Ft. Meade also had them. I've also seen then at some local reserve armories as I drive by them. With an antenna tuner (usually automatic) they can cover the whole HF spectrum. As it is a government issue, it likely can be made by several vendors to government specs and then bid upon, unless there is something so unique about it that it is a sole source contract. Some of them I inventoried when doing site inventories ( I was a US Dept. of Defense program manager) were, in fact sold to the gov't by B&W which I believe is short for Barker & Williamson who made ham transmitters in the 1950's when I was both a kid and first licensed. I'm not an antenna engineer by any means but someone who was said that essentially is was a sort of hybrid between a Zepp and a folded dipole. The extra spacing contributed to its bandwidth. He said the center had some sort of insulator with a balun transformer. It was not the most effecient antenna, but could be erected quickly and was packaged with a mast kit for field operations. The military version also had the option of stainless steel wire. Most of the ones I saw were permanently installed. I was always curious about them, but all my projects were receive-only for intercept so I never got to play with them at all. Like to hear more about them. Jon W3JT |
Can you ID this antenna
It was probably one of these:
http://www.bwantennas.com/ Works on a wide range of HF frequencies, popular with the government, but a tad expensive (upwards of $1,595.00 is a lot for a dipole) and you lose a certain amount of power in the antenna. bob k5qwg On Mon, 22 Jun 2009 05:11:09 -0700 (PDT), Gary KW4Z wrote: The other day, while passing the local Reserves building, I noticed a new antenna mounted to their tower. It was in an inverted Vee form but had approximately three white insulators that were around 6 to 8 inches in length running between the two wires of this antenna. The antenna was fed, via coax, from the bottom by what appeared to be a balun. The wire proceeded out from the balun past the bottom of the three (per side) insulators and at each end appeared to either double back, upon itself, or be attached to the top wire which was connected to the bottom wire at each end then passed through the top of each of the three (per side) insulators and ended up meeting the other sides, top wire, at, what appeared to be, a plastic mounting plate that served as a fastening point for each of the top wires and also as a top support for the antenna's middle to be connected via rope, wire, etc to either a tower or mast. The top (middle) of the antenna had no contact with the bottom middle (of the antenna), where it was fed from, but the top and bottom wires (isolated from each other as it ran from the middle to end, by three white insulators approx 6-8 inches in length) The only contact of the top wire to the bottom wire was at the extreme ends of this inverted vee type antenna where the top and bottom wires were attached to each other then each end mounted, via insulator, to some connecting point to support the height of the ends of this antenna. I've just never seen this type antenna and would love to build one. If you know the type, from the description I have given, please share the name of it and where I might be able to obtain the forumulas for calculating length. What bands does it work? Is it homebrew or commercial? Any input would be appreciated. |
Can you ID this antenna
On Jun 23, 11:48*am, Jon Teske wrote:
The B&W, which comes in several configuations, is a pretty standard military antenna. We had several of them on various buildings at Ft. Meade, where I worked and I've seen them on military posts all over. Several other commands at Ft. Meade also had them. I've also seen then at some local reserve armories as I drive by them. With an antenna tuner (usually automatic) they can cover the whole HF spectrum. As it is a government issue, it likely can be made by several vendors to government specs and then bid upon, unless there is something so unique about it that it is a sole source contract. *Some of them I inventoried when doing site inventories ( I was a US Dept. of Defense program manager) were, in fact sold to the gov't by B&W which I believe is short for Barker & Williamson who made ham transmitters in the 1950's when I was both a kid and first licensed. I'm not an antenna engineer by any means but someone who was said that essentially is was a sort of hybrid between a Zepp and a folded dipole. The extra spacing contributed to its bandwidth. He said the center had some sort of insulator with a balun transformer. *It was not the most effecient antenna, but could be erected quickly and was packaged with a mast kit for field operations. The military version also had the option of stainless steel wire. Most of the ones I saw were permanently installed. I was always curious about them, but all my projects were receive-only for intercept so I never got to play with them at all. Like to hear more about them. Jon W3JT They're found on the roof tops os US Embassy's as well. If the design incorporates a resistor there will be additional loss, but that is the trade off when you need a multiband antenna that plays well with ALE. We were issued dipoles which had to be retuned with each frequency change through out the day. Sometimes efficiency isn't everything. |
Can you ID this antenna
"Lime Light" wrote in message ... On Jun 23, 11:48 am, Jon Teske wrote: The B&W, which comes in several configuations, is a pretty standard military antenna. We had several of them on various buildings at Ft. Meade, where I worked and I've seen them on military posts all over. Several other commands at Ft. Meade also had them. I've also seen then at some local reserve armories as I drive by them. With an antenna tuner (usually automatic) they can cover the whole HF spectrum. As it is a government issue, it likely can be made by several vendors to government specs and then bid upon, unless there is something so unique about it that it is a sole source contract. Some of them I inventoried when doing site inventories ( I was a US Dept. of Defense program manager) were, in fact sold to the gov't by B&W which I believe is short for Barker & Williamson who made ham transmitters in the 1950's when I was both a kid and first licensed. I'm not an antenna engineer by any means but someone who was said that essentially is was a sort of hybrid between a Zepp and a folded dipole. The extra spacing contributed to its bandwidth. He said the center had some sort of insulator with a balun transformer. It was not the most effecient antenna, but could be erected quickly and was packaged with a mast kit for field operations. The military version also had the option of stainless steel wire. Most of the ones I saw were permanently installed. I was always curious about them, but all my projects were receive-only for intercept so I never got to play with them at all. Like to hear more about them. Jon W3JT They're found on the roof tops os US Embassy's as well. If the design incorporates a resistor there will be additional loss, but that is the trade off when you need a multiband antenna that plays well with ALE. We were issued dipoles which had to be retuned with each frequency change through out the day. Sometimes efficiency isn't everything. How much power did the military use with that type of antenna? I used to mess around at the Delaware armory communication setup (MARS?) back about twenty years ago, but I don't remember the power levels they were running. Hi, Tom!!! Ed Cregger, NM2K (I got my old callsign back after having AJ4PJ - I couldn't take being away from it) |
Can you ID this antenna
In message
, Lime Light writes On Jun 23, 11:48*am, Jon Teske wrote: The B&W, which comes in several configuations, is a pretty standard military antenna. We had several of them on various buildings at Ft. Meade, where I worked and I've seen them on military posts all over. Several other commands at Ft. Meade also had them. I've also seen then at some local reserve armories as I drive by them. With an antenna tuner (usually automatic) they can cover the whole HF spectrum. As it is a government issue, it likely can be made by several vendors to government specs and then bid upon, unless there is something so unique about it that it is a sole source contract. *Some of them I inventoried when doing site inventories ( I was a US Dept. of Defense program manager) were, in fact sold to the gov't by B&W which I believe is short for Barker & Williamson who made ham transmitters in the 1950's when I was both a kid and first licensed. I'm not an antenna engineer by any means but someone who was said that essentially is was a sort of hybrid between a Zepp and a folded dipole. The extra spacing contributed to its bandwidth. He said the center had some sort of insulator with a balun transformer. *It was not the most effecient antenna, but could be erected quickly and was packaged with a mast kit for field operations. The military version also had the option of stainless steel wire. Most of the ones I saw were permanently installed. I was always curious about them, but all my projects were receive-only for intercept so I never got to play with them at all. Like to hear more about them. Jon W3JT They're found on the roof tops os US Embassy's as well. If the design incorporates a resistor there will be additional loss, but that is the trade off when you need a multiband antenna that plays well with ALE. We were issued dipoles which had to be retuned with each frequency change through out the day. Sometimes efficiency isn't everything. Do a Google on "T2FD", and you will find lots of information on this antenna. I believe the Cebik did an analysis of it, but his articles are not as accessible as they used to be. -- Ian |
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