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#41
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Why not in metal can? You can use for example alumina. But no
ferroelectrics! (If it's a magnetic antenna) - Henry Arie de Muynck schrieb in Nachricht ... "John Miles" wrote http://www.aftenposten.no/english/lo...ticleID=609108 I've always assumed that the performance of ferrite-rod antennas in transmitting applications was limited by core saturation. Wonder if there's anything to this "invention"? I especically like the statement: "Our tiny antenna can be placed in the car or cast in metal, and is at least as good" Great, an antenna working even if cast in metal.... Arie. |
#42
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I think don't talk to much about it before reading the patent application WO
02/45210 A1 or PCT/NO01/00441. Inside there are links to other patents... Cannot say more, must read it first. One nice think about patents: You don't need to pay something for it if you use it privately. Offering a device to others is not allowed. Just make your own if possible (materials, construction, opened infos can make it impossivble). Ideal for hams, electronics hobbyists. My email address is real. Spam and Virus filtered. Regards - Henry Stepan Novotill schrieb in Nachricht ... On Wed, 17 Sep 2003 19:30:19 +0200, "Arie de Muynck" wrote: The old "Genie" garage door opener transmitters used a ferrite rod antenna. It was very thick and short. Like an AA battery. Then again, that was VHF/UHF to boot. I still have one in my scrap pile. ....Stepan |
#43
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I think don't talk to much about it before reading the patent application WO
02/45210 A1 or PCT/NO01/00441. Inside there are links to other patents... Cannot say more, must read it first. One nice think about patents: You don't need to pay something for it if you use it privately. Offering a device to others is not allowed. Just make your own if possible (materials, construction, opened infos can make it impossivble). Ideal for hams, electronics hobbyists. My email address is real. Spam and Virus filtered. Regards - Henry Stepan Novotill schrieb in Nachricht ... On Wed, 17 Sep 2003 19:30:19 +0200, "Arie de Muynck" wrote: The old "Genie" garage door opener transmitters used a ferrite rod antenna. It was very thick and short. Like an AA battery. Then again, that was VHF/UHF to boot. I still have one in my scrap pile. ....Stepan |
#44
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"Henry" wrote ...
Why not in metal can? You can use for example alumina. But no ferroelectrics! (If it's a magnetic antenna) Arie de Muynck schrieb in Nachricht Great, an antenna working even if cast in metal.... Lookup eddy currents, skin effect depth, etc. Placing an antenna in a _closed_ conductive box is not the best way to make an efficient antenna. Only if the box has a slot the energy may seep though that - but that's not in "Our tiny antenna can be placed in the car or cast in metal, and is at least as good". I see casting in metal as a closed box. The antenna will be shielded unless they use VERY slow changing signals. Not good for efficiency either. Take a working old MW transistor radio with ferrite antenna and wrap it in Alum foil. Make sure the edges make contact. You may puncture small holes to hear the sound - or rather, notice the lack of it. Arie de Muynck |
#45
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"Henry" wrote ...
Why not in metal can? You can use for example alumina. But no ferroelectrics! (If it's a magnetic antenna) Arie de Muynck schrieb in Nachricht Great, an antenna working even if cast in metal.... Lookup eddy currents, skin effect depth, etc. Placing an antenna in a _closed_ conductive box is not the best way to make an efficient antenna. Only if the box has a slot the energy may seep though that - but that's not in "Our tiny antenna can be placed in the car or cast in metal, and is at least as good". I see casting in metal as a closed box. The antenna will be shielded unless they use VERY slow changing signals. Not good for efficiency either. Take a working old MW transistor radio with ferrite antenna and wrap it in Alum foil. Make sure the edges make contact. You may puncture small holes to hear the sound - or rather, notice the lack of it. Arie de Muynck |
#46
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You made great interesting experiments!
The electrical field will suffer with a alumni foil, surely. Magnetics will go thru. - Henry Arie de Muynck schrieb in Nachricht ... "Henry" wrote ... Why not in metal can? You can use for example alumina. But no ferroelectrics! (If it's a magnetic antenna) Arie de Muynck schrieb in Nachricht Great, an antenna working even if cast in metal.... Lookup eddy currents, skin effect depth, etc. Placing an antenna in a _closed_ conductive box is not the best way to make an efficient antenna. Only if the box has a slot the energy may seep though that - but that's not in "Our tiny antenna can be placed in the car or cast in metal, and is at least as good". I see casting in metal as a closed box. The antenna will be shielded unless they use VERY slow changing signals. Not good for efficiency either. Take a working old MW transistor radio with ferrite antenna and wrap it in Alum foil. Make sure the edges make contact. You may puncture small holes to hear the sound - or rather, notice the lack of it. Arie de Muynck |
#47
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You made great interesting experiments!
The electrical field will suffer with a alumni foil, surely. Magnetics will go thru. - Henry Arie de Muynck schrieb in Nachricht ... "Henry" wrote ... Why not in metal can? You can use for example alumina. But no ferroelectrics! (If it's a magnetic antenna) Arie de Muynck schrieb in Nachricht Great, an antenna working even if cast in metal.... Lookup eddy currents, skin effect depth, etc. Placing an antenna in a _closed_ conductive box is not the best way to make an efficient antenna. Only if the box has a slot the energy may seep though that - but that's not in "Our tiny antenna can be placed in the car or cast in metal, and is at least as good". I see casting in metal as a closed box. The antenna will be shielded unless they use VERY slow changing signals. Not good for efficiency either. Take a working old MW transistor radio with ferrite antenna and wrap it in Alum foil. Make sure the edges make contact. You may puncture small holes to hear the sound - or rather, notice the lack of it. Arie de Muynck |
#48
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"Henry" wrote You made great interesting experiments! The electrical field will suffer with a alumni foil, surely. Magnetics will go thru. You didn't do the experiment. Regards, Arie de Muynck |
#49
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"Henry" wrote You made great interesting experiments! The electrical field will suffer with a alumni foil, surely. Magnetics will go thru. You didn't do the experiment. Regards, Arie de Muynck |
#50
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I read the patent application meantime. But I must say there is not much
content in it. Especially nothing how to calculate dimensions, materials or taken measurements. My understanding is that it is a helix antenna supported with a ferrite powder rod in the axis. And it is electrical much longer than the wavelength used. Adaption to the "ether" field Z(0) with up to 4 stages of different winding/mu(r) value materials. A magnetical antenna very similar to the electrical Yagi antenna. "The antenna works up to 500MHz", he says. "Greater frequency requires lower mu(r)." Sorry, maybe it won't work at all. I'm not an antenna expert. Maybe the author of the patent will directly respond here sometime? What do you think? - Henry Arie de Muynck schrieb in Nachricht ... "Henry" wrote You made great interesting experiments! The electrical field will suffer with a alumni foil, surely. Magnetics will go thru. You didn't do the experiment. Regards, Arie de Muynck |
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