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Mesh curtain antenna
My latest antenna is up!
It is a window mesh curtain 8 foot by 100 foot about 1 foot off the ground. It is an all bander with the xmitter tuner on all the time, later I will trim it so I can leave the internal tuner off. At the moment the red light comes on when I am right in the center only of the top band and the SWR reads 1.5 for the middle section only!. Presume the tuner cannot handle above 1.5 on top band. Very, very quiet antenna, but it has been up less than 24 hours. Feed is on one side only with the ground connection about 2 inches away on the same side with the connections at the bottom some what towards the center of the curtain length ways.Basically it is a long one wall Faraday shield but without a drain ground on the front side. Will find a relay so I can make it bi directional |
Mesh curtain antenna
Art Unwin wrote:
My latest antenna is up! It is a window mesh curtain 8 foot by 100 foot about 1 foot off the ground. Big deal. All that is, depending on how it is fed, is either a fat dipole or a fat long wire. -- Jim Pennino Remove .spam.sux to reply. |
Mesh curtain antenna
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Mesh curtain antenna
Ian Jackson wrote:
In message , writes Art Unwin wrote: My latest antenna is up! It is a window mesh curtain 8 foot by 100 foot about 1 foot off the ground. Big deal. All that is, depending on how it is fed, is either a fat dipole or a fat long wire. As they say, "Never mind the quality - feel the width!" I tried this once myself, but the XYL yelled at me to put the curtain back in the shower. It had pretty poor ShoWeR anyhow...... - 73 de Mike N3LI - |
Mesh curtain antenna
On Mar 9, 1:04*pm, Art Unwin wrote:
My latest antenna is up! It is a window mesh curtain 8 foot by 100 foot about 1 foot off the ground. It is an all bander with the xmitter tuner on all the time, later I will trim it so I can leave the internal tuner off. At the moment the red light comes on when I am right in the center only of the top band and the SWR reads 1.5 for the middle section only!. Presume the tuner cannot handle above 1.5 on top band. Very, very quiet antenna, but it has been up less than 24 hours. Feed is on one side only with the ground connection about 2 inches away on the same side with the connections at the bottom some what towards the center of the curtain length ways.Basically it is a long one wall Faraday shield but without a drain ground on the front side. *Will find a relay so I can make it bi directional Very very quite antenna tells the whole story. Jimmie |
Mesh curtain antenna
Art Unwin wrote:
Very, very quiet antenna, but it has been up less than 24 hours. Feed is on one side only with the ground connection about 2 inches away on the same side with the connections at the bottom some what towards the center of the curtain length ways. So he is center feeding a large curtain with a "_2 inch_" wide feed. Yup, that WILL very definitely be quiet. I hope the tuner has a lot of loss in the way before the "antenna" (chortle) to dissipate the 99.999% of the power fed to the short at the end. Basically it is a long one wall Faraday shield but without a drain ground on the front side. It's not a Faraday shield if it's not completely surrounding something. I'd suggest a smaller one. Of tinfoil. Around your head. It won't help, but it would be amusing. tom K0TAR |
Mesh curtain antenna
On Mar 9, 7:58*pm, tom wrote:
Art Unwin wrote: Very, very quiet antenna, but it has been up less than 24 hours. Feed is on one side only with the ground connection about 2 inches away on the same side with the connections at the bottom some what towards the center of the curtain length ways. So he is center feeding a large curtain with a "_2 inch_" wide feed. Yup, that WILL very definitely be quiet. *I hope the tuner has a lot of loss in the way before the "antenna" (chortle) to dissipate the 99.999% of the power fed to the short at the end. Basically it is a long one wall Faraday shield but without a drain ground on the front side. It's not a Faraday shield if it's not completely surrounding something. * I'd suggest a smaller one. *Of tinfoil. *Around your head. *It won't help, but it would be amusing. tom K0TAR A Faraday shield allows for magnetic and elerctrical fields to separate and cancell leaving a RF current thast radios are designed to handle. The shield unlike what we view as radiators has two side that are independent of each other where as a "normal" radiators surface is not separated electrically. The Faraday shield operates at 90 degrees to an oncomming signal by a blocking method and does not operate as a recieving type surface that is directly connected to a radio. The Faraday shield as a single wall still has a blocking action as fields can encircle the wall but it cannot protect all. It does however protect the rear surface from field impingement and the field usually will connefct to a alternate surface leaving a void directly behind the shielding wall. The Faraday shield on the other hand is an enclosure that shields the inside from encroachment on the outside such thast fields do not interfere with activities within. It does not perform the function of field separation. In most radio circuits you will see examples of bot enclosures and shields where the latter incorporates physically unconnected surfaces for electricaly closed loops. I don't mind your postings Tom as it provides those that are educated some idea of your true standing in life. With respect to a closely aligned feed which to your mind leaves an imediate short;. I suggest you look at a three band dipole all connected at the same point. Each dipole provides a low resistance path for a particular applied frequency in its seach for a closed circuit. The applied current will not divert to a path of higher resistance or impedance in this case because we have to consider the effect of phase differences. With these sort of actions we can have several different paths for the current to follow but I assure you that it will pick the same one every time dependent on the frequency applied. Now to the wire mesh curtain. It provides a separate low impedence path for every frequency applied to it as well as a separate path for the displacement current that encloses a separate field ( see my page) which has the abilitity to accellerate mass as with an electric gun.The maximum accelleration applied to mass is obviously determined by its intrinsic mass where a minimum mass determines the speed of light. Today the smallest particle found is that of a Neutrino thus one can see the connection of the Sun to communication as we see it today. Regarding your description of the shield to a long wire or dipole, gthe curtain or shield does not provide a electrical connection for both sides of the shield as a dipole or long wire does. See Tom, your past postings are completely devoid of technical content and probably provide all readers with a silent chucklel By the way, a curtain is able to supply a very large aperture which is synonimous with the amount of gain it supplies. You might want to ponder on that aspect before you disparage it. The above is provided for you and your friends to salivate apon so you may provide a few more chuckles to those on the side lines. Note I have left some grammerr and spelling errors for you to comment upon in the absence of any technical content. Cheers and beers Art Unwin KB9MZ.....xg |
Mesh curtain antenna
On Mar 10, 4:56*pm, Art Unwin wrote:
On Mar 9, 7:58*pm, tom wrote: . The Faraday shield as a single wall still has a blocking action as fields can encircle the wall but it cannot protect all. It does however protect the rear surface from field impingement and the field usually will connefct to a alternate surface leaving a void directly behind the shielding wall. That is nonsense. The Faraday shield is defined as an enclosure, The Faraday Cage. The Faraday shield on the other hand is an enclosure that shields the inside from encroachment on the outside such that fields do not interfere with activities within. Faraday conveyed his ideas in clear and simple language. Something Unwin is incapable of. |
Mesh curtain antenna
Art Unwin wrote:
A Faraday shield allows for magnetic and elerctrical fields to separate and cancell leaving a RF current thast radios are designed to handle No, that's absolutely incorrect. Nothing is separated. And what's left over, if anything measurable is, is an electromagnetic wave. The shield unlike what we view as radiators has two side that are independent of each other where as a "normal" radiators surface is not separated electrically. The Faraday shield operates at 90 degrees to an oncomming signal by a blocking method and does not operate as a recieving type surface that is directly connected to a radio. No it doesn't. You are wrong. The Faraday shield as a single wall still has a blocking action as fields can encircle the wall but it cannot protect all. It does however protect the rear surface from field impingement and the field usually will connefct to a alternate surface leaving a void directly behind the shielding wall. The Faraday shield on the other hand is an enclosure that shields the inside from encroachment on the outside such thast fields do not interfere with activities within. It does not perform the function of field separation. In most radio circuits you will see examples of bot enclosures and shields where the latter incorporates physically unconnected surfaces for electricaly closed loops. I don't mind your postings Tom as it provides those that are educated some idea of your true standing in life. With respect to a closely aligned feed which to your mind leaves an imediate short;. I suggest you look at a three band dipole all connected at the same point. Each dipole provides a low resistance path for a particular applied frequency in its seach for a closed circuit. The applied current will not divert to a path of higher resistance or impedance in this case because we have to consider the effect of phase differences. With these sort of actions we can have several different paths for the current to follow but I assure you that it will pick the same one every time dependent on the frequency applied. Now to the wire mesh curtain. It provides a separate low impedence path for every frequency applied to it as well as a separate path for the displacement current that encloses a separate field ( see my page) which has the abilitity to accellerate mass as with an electric gun.The maximum accelleration applied to mass is obviously determined by its intrinsic mass where a minimum mass determines the speed of light. Today the smallest particle found is that of a Neutrino thus one can see the connection of the Sun to communication as we see it today. Regarding your description of the shield to a long wire or dipole, gthe curtain or shield does not provide a electrical connection for both sides of the shield as a dipole or long wire does. See Tom, your past postings are completely devoid of technical content and probably provide all readers with a silent chucklel By the way, a curtain is able to supply a very large aperture which is synonimous with the amount of gain it supplies. You might want to ponder on that aspect before you disparage it. The above is provided for you and your friends to salivate apon so you may provide a few more chuckles to those on the side lines. Note I have left some grammerr and spelling errors for you to comment upon in the absence of any technical content. Cheers and beers Art Unwin KB9MZ.....xg And I'll just summarize all the last part, since it would be a total waste of time to comment individually on points - YOU ARE WRONG. Totally, completely, and terribly wrong. And no, I'm not going into how or why, because you never ever listen or understand. tom K0TAR |
Mesh curtain antenna
On Mar 10, 8:07*pm, tom wrote:
Art Unwin wrote: A Faraday shield allows for magnetic and elerctrical fields to separate and cancell leaving a RF current thast radios are designed to handle No, that's absolutely incorrect. *Nothing is separated. *And what's left over, if anything measurable is, is an electromagnetic wave. The shield unlike what we view as radiators has two side that are independent of each other where as a "normal" radiators surface is not separated electrically. The Faraday shield operates at 90 degrees to an oncomming signal by a blocking method and does not operate as a recieving type surface that is directly connected to a radio. No it doesn't. *You are wrong. * The Faraday shield as a single wall still has a blocking action as fields can encircle the wall but it cannot protect all. It does however protect the rear surface from field impingement and the field usually will connefct to a alternate surface leaving a void directly behind the shielding wall. The Faraday shield on the other hand is an enclosure that shields the inside from encroachment on the outside such thast fields do not interfere with activities within. It does not perform the function of field separation. In most radio circuits you will see examples of bot enclosures and shields where the latter incorporates physically unconnected surfaces for electricaly closed loops. I don't mind your postings Tom as it provides those that are educated some idea of your true standing in life. With respect to a closely aligned feed which to your mind leaves an imediate short;. I suggest you look at a three band dipole all connected at the same point. Each dipole provides a low resistance path for a particular applied frequency in its seach for a closed circuit. The applied current will not divert to a path of higher resistance or impedance in this case because we have to consider the effect of phase differences. With these sort of actions we can have several different paths for the current to follow but I assure you that it will pick the same one every time dependent on the frequency applied. Now to the wire mesh curtain. It provides a separate low impedence path for every frequency applied to it as well as a separate path for the displacement current that encloses a separate field ( see my page) which has the abilitity to accellerate mass as with an electric gun.The maximum accelleration applied to mass is obviously determined by its intrinsic mass where a minimum mass determines the speed of light. Today the smallest particle found is that of a Neutrino thus one can see the connection of the Sun to communication as we see it today. Regarding your description of the shield to a long wire or dipole, gthe curtain or shield does not provide a electrical connection for both sides of the shield as a dipole or long wire does. See Tom, your past postings are completely devoid of technical content and probably provide all readers with a silent chucklel By the way, a curtain is able to supply a very large aperture which is synonimous with the amount of gain it supplies. You might want to ponder on that aspect before you disparage it. The above is provided for you and your friends to salivate apon so you may provide a few more chuckles to those on the side lines. Note I have left some grammerr and spelling errors for you to comment upon in the absence of any technical content. Cheers and beers Art Unwin KB9MZ.....xg And I'll just summarize all the last part, since it would be a total waste of time to comment individually on points - YOU ARE WRONG. *Totally, completely, and terribly wrong. And no, I'm not going into how or why, because you never ever listen or understand. tom K0TAR Oh My. I am wrong but you are unable to describe how I am wrong,how convenient! You need to brush up on attenuation versus skin depth, surface conduction and a host of other things such as a sealed surface can be considered as an aperture with respect to shielding. I would recommend a book on shielding etc by Ralph Morrison 5 th edition that will bring you up to date on the function of perforated shielding plates, screening etc.Just saying that I am wrong without explanation or explaining your record on the subject is nothing more than the voice of a child exercising free speech.If you can provide technical data to support your position we can discuss but just saying one is wrong serves nobody. One thing you really need to understand is the nature of a accellerated and decellerated charge and its connection with a time varient current, the latter being the only connection that a xmitter or rcvr can handle to provide communication and its connection with a parallel tank circuit. Have a happy day Art |
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