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#11
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On Jul 10, 11:17 am, John Smith wrote:
W3CQH wrote: wrote in message ... A helix wound antenna with a double winding? Really? - 'Doc Double winding - in which direction and spaced how far apart in each direction? This URL, of a patent of an antenna which is growing in commercial use, describes just such a winding and how it is constructed for real world use. I am almost positive this is the "double helix winding method" which Art is making reference to: http://www.patentstorm.us/patents/7187335/fulltext.html In particular, this reference in the patent: "It has been found that interlacing a false winding into a current enhancing unit (such as the top unit winding shown in FIG. 6) or a radiation resistance unit (such as a helix as shown in FIG. 7) enhances the bandwidth of the top unit as well as improves the current profile along the antenna. The interlaced false winding has little effect on the resonant frequency of the antenna system." Regards, JS What you are refering to i believe is the Rhode Island antenna that has been attacked by all of ham radio but again it could be another follow up new antenna tho it seems a bit soon since they had to resubmit the first patent to get it accepted. John, imagine the following 1 a rcp and a lcp helix driven in parallel with counterpoise. What would the ensueing gain consist of? 2 a rcp and a lcp helix driven antenna connected at the top and fed with out a counterpoise ( assumption is that windings do not come in contact with each other) What would the ensuing gain, if any, consist of ? Would either 1 or 2 produce a negative total gain? I am really having a difficult time understanding why hams THINK so bad of this type of antenna, with close windings or in pitched form You just can't stop wire radiating so where are they coming from? Regards Art Regards Art Nobody has supplied any reasoning of what radiation a ham could expect from such an arrangement. Yet anybody can check it out forthemselves without unsubstantiated off the cuff comments meant to inflict pain |
#12
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Art Unwin wrote:
... What you are refering to i believe is the Rhode Island antenna that has been attacked .... Art Regards Art Nobody has supplied any reasoning of what radiation a ham could expect from such an arrangement. Yet anybody can check it out forthemselves without unsubstantiated off the cuff comments meant to inflict pain It is the "Distributed Load Monopole" (DLM) antenna by Robert Vincent ... I have a 50 ft. one in my front yard and disquised as a flagpole, for 80m. At the back of the house, and hidden from view, is a 1/2 version for 10m. For me, it is a perfect design ... I have not incorporated the "interlaced winding(s)", yet ... Regards, JS |
#13
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![]() "Art Unwin" wrote in message ... Tell you what, get some wire twice the WL of the frequency you are interested in. Wind a close coil any diameter with it until half the wire is used then change direction and come back without changing wire winding direction and wind the wire on top of the first coil where you finish with two wires to feed. Put a variometer in series with it and then get on the air. Now this is not exactly in equilibrium because one coil is a larger diameter than the other. Nor is the wire pre twisted pair which nullifies near field noise to my thinking. Now you have a helix style antenna but without the helix. Coat the antenna with an alkyd type solution before you slide it off the tube since the inside coil must be exposed the same way the outside coil is exposed OK, I can do most of that. However, I went to your page for some variometer details, as I don't have one. No luck. From other reading it appears to be a loosely couple balun or un-un. But near there on your page, I discovered some verbiage about building an antenna and saw the reference to a 12-inch diameter. Good find, as I was going to go smaller. If I wound the thing on cardboard (like a big empty ice cream tub from the ice cream store), could I avoid having to take the coil(s) off the form? What about a paint bucket or an empty pool chlorine tub? I'd sorta like to skip that alkyd step. Messy. Need more variometer data, but I'll dig for that |
#14
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"Clark Kent" wrote in message
... ( Big snip) Need more variometer data, but I'll dig for that Variometer design he http://www.qsl.net/in3otd/variodes.html Cheers, John |
#15
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![]() "Clark Kent" wrote in message ... "Art Unwin" wrote in message ... Tell you what, get some wire twice the WL of the frequency you are interested in. Wind a close coil any diameter with it until half the wire is used then change direction and come back without changing wire winding direction and wind the wire on top of the first coil where you finish with two wires to feed. Put a variometer in series with it and then get on the air. Now this is not exactly in equilibrium because one coil is a larger diameter than the other. Nor is the wire pre twisted pair which nullifies near field noise to my thinking. Now you have a helix style antenna but without the helix. Coat the antenna with an alkyd type solution before you slide it off the tube since the inside coil must be exposed the same way the outside coil is exposed OK, I can do most of that. However, I went to your page for some variometer details, as I don't have one. No luck. From other reading it appears to be a loosely couple balun or un-un. But near there on your page, I discovered some verbiage about building an antenna and saw the reference to a 12-inch diameter. Good find, as I was going to go smaller. If I wound the thing on cardboard (like a big empty ice cream tub from the ice cream store), could I avoid having to take the coil(s) off the form? What about a paint bucket or an empty pool chlorine tub? I'd sorta like to skip that alkyd step. Messy. Need more variometer data, but I'll dig for that I thought I might try and experiment with building one, since it seems simple. The variometer is a deal killer however. Is there any reason a transmatch/balun couldn't be used? |
#16
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On Jul 11, 2:32 pm, "Wayne" wrote:
"Clark Kent" wrote in message ... "Art Unwin" wrote in message ... Tell you what, get some wire twice the WL of the frequency you are interested in. Wind a close coil any diameter with it until half the wire is used then change direction and come back without changing wire winding direction and wind the wire on top of the first coil where you finish with two wires to feed. Put a variometer in series with it and then get on the air. Now this is not exactly in equilibrium because one coil is a larger diameter than the other. Nor is the wire pre twisted pair which nullifies near field noise to my thinking. Now you have a helix style antenna but without the helix. Coat the antenna with an alkyd type solution before you slide it off the tube since the inside coil must be exposed the same way the outside coil is exposed OK, I can do most of that. However, I went to your page for some variometer details, as I don't have one. No luck. From other reading it appears to be a loosely couple balun or un-un. But near there on your page, I discovered some verbiage about building an antenna and saw the reference to a 12-inch diameter. Good find, as I was going to go smaller. If I wound the thing on cardboard (like a big empty ice cream tub from the ice cream store), could I avoid having to take the coil(s) off the form? What about a paint bucket or an empty pool chlorine tub? I'd sorta like to skip that alkyd step. Messy. Need more variometer data, but I'll dig for that I thought I might try and experiment with building one, since it seems simple. The variometer is a deal killer however. Is there any reason a transmatch/balun couldn't be used? The variometer allows the frequency to be moved as a multiple of a wavelength. Thus allows your antenna to vary as you turn the knob on the radio. If you do not use a variometer then you just have to hope that one of the many suitable swr points rest upon your frequency of choice. This can also be simulated by a series of jumpers or a slider method over the surface of the windings. For me I prefer a variometer since the motor drive can be that which is dismantled from the radio's tuner such that you have an automatic set up the same as the new variable antenna that hit the market a few years ago except this design is less than $100.....big difference.......and much much smaller....... and yes the variometer is placed on the top of the tower with your 160M rotatable antenna. Don't know where I will go next! Sweaty...need a shower Unwinantennas.com/ |
#17
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![]() "Art Unwin" wrote in message ... On Jul 11, 2:32 pm, "Wayne" wrote: "Clark Kent" wrote in message ... "Art Unwin" wrote in message ... Tell you what, get some wire twice the WL of the frequency you are interested in. Wind a close coil any diameter with it until half the wire is used then change direction and come back without changing wire winding direction and wind the wire on top of the first coil where you finish with two wires to feed. Put a variometer in series with it and then get on the air. Now this is not exactly in equilibrium because one coil is a larger diameter than the other. Nor is the wire pre twisted pair which nullifies near field noise to my thinking. Now you have a helix style antenna but without the helix. Coat the antenna with an alkyd type solution before you slide it off the tube since the inside coil must be exposed the same way the outside coil is exposed OK, I can do most of that. However, I went to your page for some variometer details, as I don't have one. No luck. From other reading it appears to be a loosely couple balun or un-un. But near there on your page, I discovered some verbiage about building an antenna and saw the reference to a 12-inch diameter. Good find, as I was going to go smaller. If I wound the thing on cardboard (like a big empty ice cream tub from the ice cream store), could I avoid having to take the coil(s) off the form? What about a paint bucket or an empty pool chlorine tub? I'd sorta like to skip that alkyd step. Messy. Need more variometer data, but I'll dig for that I thought I might try and experiment with building one, since it seems simple. The variometer is a deal killer however. Is there any reason a transmatch/balun couldn't be used? The variometer allows the frequency to be moved as a multiple of a wavelength. Thus allows your antenna to vary as you turn the knob on the radio. If you do not use a variometer then you just have to hope that one of the many suitable swr points rest upon your frequency of choice. This can also be simulated by a series of jumpers or a slider method over the surface of the windings. For me I prefer a variometer since the motor drive can be that which is dismantled from the radio's tuner such that you have an automatic set up the same as the new variable antenna that hit the market a few years ago except this design is less than $100.....big difference.......and much much smaller....... and yes the variometer is placed on the top of the tower with your 160M rotatable antenna. Don't know where I will go next! Sweaty...need a shower Unwinantennas.com/ Suddenly, here's just a TON of stuff that needs some good sense sprinkled on it. Just a few highlights: I just took another look at the website and further examined the graphs at the bottom. Per your instructions, using approximately 2000 ft of wire means the antenna is wound for a wl of 1000 ft, 305 meters or around 1 MHz. How is it you're getting a decent SWR nearly everywhere from 1.0 to 100 MHz? Look, the WORST number for SWR is about 4:1, well within the range of any decent tuner. BTW, it looks like the response of a comb filter, except that the cancellation frequencies between the reinforcements don't look as lossy as they should look. The variometer will do variable transformer coupling. OK fine, but I think you should have provided a description for one. The link to http://www.qsl.net/in3otd/variodes.html was instructive but ... I have no idea what coil inductances to shoot for. Groping in the dark is not fun. What does it mean to move the frequency as a multiple of wavelength? What does it mean for the antenna to vary as I turn the knob on the radio? I've got decades of experience with this hobby and that does not compute. You shouldn't throw this stuff out and figure we're mind readers. 160m rotatable antenna? I don't travel in those circles. If that was a joke, I guess I need my sense of humor recalibrated. Here's my own "tell you what": I'll wind one of these things for 20m, which isn't a lot of wire. I have an antenna analyzer that will tell me a few nice things about what I have. Then if the SWR is anything like reasonable, it's Kenwood Time! I'll check for who I can hear and try working him. ... and I'll check for WWV on 15. I can usually hear him any day, often on a cheap portable radio with a whip antenna. Using a local ham (eliminating the bulk of QSB) I can compare antennas for equal S-meter readings with a switchable attenuator in line with the better antenna. That will settle it for me. |
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