Re: [Elecraft] We need to develop the Ideal Antenna!
Dunno if this is ideal, however, I have 2 Hustler 6BTV's and they can be fed together as a dipole. I plan to put them in a pvc pipe, for wx resistance and some mechanical stability, and use them as a 6-band slopper, leaning toward my tower and fed with 7/8 line to handle vswr excursions. Support point is around 40 ft, so it may work in some trees, as well. Brgds, Dave, N3HE -- View this message in context: http://elecraft.365791.n2.nabble.com/We-need-to-develop-the-Ideal-Antenna-tp6364475p6365185.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] We need to develop the Ideal Antenna!
Bob, An interesting idea for a multiband centre-fed antenna was described by W4JRW in the December 1960 issue of QST, Multiband Antennas using Decoupling Stubs. The decoupling stubs that he used are not hung at right angles to the antenna wire, but are horizontal stubs which results in a tidy arrangement. In fact one of the antennas he described uses a length of tubular Twin-Lead, one conductor forming the antenna and the second conductor cut and removed in places to make the decoupling stubs, which results in a light weight antenna easy to carry. 73, Geoff GM4ESD On Saturday, May 14, 2011 11:13 PM, AB5N 7000...@gmail.com wrote: Wow Guys, thanks! It's great.. although this is my 5th sunspot cycle on the air, I am still challenged with projects like this- which I can use help with. Thanks for all the ideas! I guess I have come to the conclusion that nobody has really run the gamut trying antenna designs for the KX-1. It's requirements are unique (the tuner etc). I'm a folded-dipole fan... and use a Carolina Windom for my main general Hf antenna with great success. OK, I'll run the gamut... with my goal being to fulfill the above criteria. I'll take into considerations all the suggestions above as well. Traps may be involved... and clip-on elements. The downside of the 25 ft wire and counterpoise is that you pick up lots of internal processor noise from the KX-1. It is also just such a compromise. As far as if my KX-1 is actually receiving correctly.. who knows? It's sensitivity is adequate, but it is pretty deaf compared to say my FT-817. Because of the low noise floor, with any signal you have a chance of working with 4 watts -can be heard. Back to the bench! Bob-AB5N __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] We need to develop the Ideal Antenna!
Bob/AB5N wrote of an antenna for the KX1: I believe the criteria for an excellent antenna will be as follows: 1. Will match up well using the internal tuner on all four bands. 2. Has enough metal in the air to provide adequate microvolts to the RX - to make it function well without being overloaded. 3. Provides some gain - or at least a clean predictable pattern 4. Is light, compact and easy to deploy. Don/W3FPR replied: Some like the Carolina Windom, but I don't like any unbalanced antennas, and have a high preference for center fed antennas... It sounds as if Bob is describing an antenna for portable use, such as at a campsite or pic-nic area. Regardless, I have played around with antennas to use in such situations for more than 30 years and wholeheartedly agree about both the generally unsatisfactory nature of unbalanced antennas (especially for multi-band use), and the ease-of-use plus very satisfactory performance of center-fed antennas. I long ago settled on a resonant dipole as the ideal radiator for this application. I would suggest a trap antenna with traps for 40 and 20 meters. Feed it with balanced feedline cut a half wavelength (or multiple) on 80 meters... I dislike traps on my dipoles because of the way they narrow the the range of acceptable VSWR, the complexity they introduce, the weight and bulk they add to the radiator, and (when used with simple QRP rigs that may have marginal harmonic suppression) the manner in which they can be effective harmonic radiators. ...build a coax fed trap antenna for 40, 30 and 20 meters (traps for 30 and 20), and carry along 2 33 foot lengths of wire - insulators on one end and an alligator clip on the other - add the wires to each end of the radiator. ...carry that concept a bit further, and build the antenna for 20 meters with no traps and then add a set wires for use on 30 meters, another set of wires for 40, and yet another set for 80. The approach that I found worked best for me was an antenna that was a full-length 40m dipole (66 feet), with each leg broken in six places with a home-made PCV tubing insulator with integral jumper and clip so that the appropriate length dipole can be established for all seven HF bands between 10m and 40m. I built the antenna for all these bands for use with any rig, not just the limited coverage of a K1 or KX1. It works better than any other antenna I've ever used in a field environment. It typically takes less than a minute to alter insulator jumper configuration to switch to another band. It meets *all* of the desired criteria listed by Bob, to which I would add 5. Is very inexpensive and quick to home-brew. (I have a pdf file with construction details, diagrams, and photos that I'll e-mail to anyone on request.) I use the technique that you suggest of attaching a 33-foot segment to each leg for 80m operation, which is rare for me. Mike / KK5F __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] We need to develop the Ideal Antenna!
Wow Guys, thanks! It's great.. although this is my 5th sunspot cycle on the air, I am still challenged with projects like this- which I can use help with. Thanks for all the ideas! I guess I have come to the conclusion that nobody has really run the gamut trying antenna designs for the KX-1. It's requirements are unique (the tuner etc). I'm a folded-dipole fan... and use a Carolina Windom for my main general Hf antenna with great success. OK, I'll run the gamut... with my goal being to fulfill the above criteria. I'll take into considerations all the suggestions above as well. Traps may be involved... and clip-on elements. The downside of the 25 ft wire and counterpoise is that you pick up lots of internal processor noise from the KX-1. It is also just such a compromise. As far as if my KX-1 is actually receiving correctly.. who knows? It's sensitivity is adequate, but it is pretty deaf compared to say my FT-817. Because of the low noise floor, with any signal you have a chance of working with 4 watts -can be heard. Back to the bench! Bob-AB5N -- View this message in context: http://elecraft.365791.n2.nabble.com/We-need-to-develop-the-Ideal-Antenna-tp6360270p6364014.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] We need to develop the Ideal Antenna!
Hi Guys- Well, I'm in week two of enjoyment with my new KX-1. I did have a few problems in assembling, but that is history. This little rig has a simple receiver which has only half the sensitivity of a usual radio. As well, we are dealing with 3-4 watts TX out max. We have to have an excellent antenna. I've tried the suggested 25 ft. long wire with radials. Ah, it's not good enough. I even got some strange RX-feedback internally at some frequencies using it. I believe the criteria for an excellent antenna will be as follows: 1. Will match up well using the internal tuner on all four bands. 2. Has enough metal in the air to provide adequate microvolts to the RX - to make it function well without being overloaded. 3. Provides some gain - or at least a clean predictable pattern 4. Is light, compact and easy to deploy. My inkling is that a normal Carolina Windom may be the thing. I'll work on developing a micro-QRP version. What doesn't work? Classic G5RV (102 Ft) - will not load on any band with tuner. Offset-Zepp fed with Coax (75'x25') What say guys? Anybody have superb luck with an antenna yet? Bob-AB5N -- View this message in context: http://elecraft.365791.n2.nabble.com/We-need-to-develop-the-Ideal-Antenna-tp6360270p6360270.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] We need to develop the Ideal Antenna!
Bob, How about just a basic dipole? Or, a fan dipole that resonates on the appropriate bands. 73, Henry - K4TMC -Original Message- From: AB5N 7000...@gmail.com To: elecraft@mailman.qth.net Sent: Fri, May 13, 2011 1:31 pm Subject: [Elecraft] We need to develop the Ideal Antenna! Hi Guys- Well, I'm in week two of enjoyment with my new KX-1. I did have a few problems in assembling, but that is history. This little rig has a simple receiver which has only half the sensitivity of a usual radio. As well, we are dealing with 3-4 watts TX out max. We have to have an excellent antenna. I've tried the suggested 25 ft. long wire with radials. Ah, it's not good enough. I even got some strange RX-feedback internally at some frequencies using it. I believe the criteria for an excellent antenna will be as follows: 1. Will match up well using the internal tuner on all four bands. 2. Has enough metal in the air to provide adequate microvolts to the RX - to make it function well without being overloaded. 3. Provides some gain - or at least a clean predictable pattern 4. Is light, compact and easy to deploy. My inkling is that a normal Carolina Windom may be the thing. I'll work on developing a micro-QRP version. What doesn't work? Classic G5RV (102 Ft) - will not load on any band with tuner. Offset-Zepp fed with Coax (75'x25') What say guys? Anybody have superb luck with an antenna yet? Bob-AB5N -- View this message in context: http://elecraft.365791.n2.nabble.com/We-need-to-develop-the-Ideal-Antenna-tp6360270p6360270.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] We need to develop the Ideal Antenna!
Bob, Actually, a properly functioning KX1 has an MDS of better than -130 dBm, so it actually is a sensitive receiver. Some like the Carolina Windom, but I don't like any unbalanced antennas, and have a high preference for center fed antennas, they are easier to tame, and if the feedline leaves the antenna at right angles from the center, seldom do RF-in-the-shack problems emerge. The KXAT1 has a more limited range on 80 meters than the other bands just because the total inductance and capacitance is limited - only 3 choices of each. I would suggest a trap antenna with traps for 40 and 20 meters. Feed it with balanced feedline cut a half wavelength (or multiple) on 80 meters - the tuner should be able to match it on 30 meters and the half wavelength of feedline on 80 meters should present a feedpoint impedance close to that at the antenna center (50 to 75 ohms) for 80, 40, and 20 (assuming the traps are used). I have not actually built such an antenna, but the theory says it should work just fine. Keep the balanced feedline supported along its entire length and don't forget that there is a velocity factor to consider when determining a half wavelength - if you cannot do that, add a trap for 30 meters and feed it with any length of coax. Coaxial traps are not difficult to build, and for QRP use, can even use RG174 on a piece of 1/2 inch PVC for a form. Doug DeMaw (SK) W1FB had information on building traps like that in QST a very long time ago (try in the 1980s). Also see the W1FB Antenna Notebook and/or the article in QST for Decenber 1984 page 37 by N4UU. Gary o'Neil N3GO also has some good information about coaxial traps on the web (use Google). I realize that a 135 foot long antenna is not easy to deploy, so I would suggest an alternative - build a coax fed trap antenna for 40, 30 and 20 meters (traps for 30 and 20), and carry along 2 33 foot lengths of wire - insulators on one end and an alligator clip on the other - when you want to operate 80 meters, add the wires to each end of the radiator. You could carry that concept a bit further, and build the antenna for 20 meters with no traps and then add a set wires for use on 30 meters, another set of wires for 40, and yet another set for 80. clip on the wires for whichever band you want to operate. That is my nickel's worth. 73, Don W3FPR On 5/13/2011 1:31 PM, AB5N wrote: Hi Guys- Well, I'm in week two of enjoyment with my new KX-1. I did have a few problems in assembling, but that is history. This little rig has a simple receiver which has only half the sensitivity of a usual radio. As well, we are dealing with 3-4 watts TX out max. We have to have an excellent antenna. I've tried the suggested 25 ft. long wire with radials. Ah, it's not good enough. I even got some strange RX-feedback internally at some frequencies using it. I believe the criteria for an excellent antenna will be as follows: 1. Will match up well using the internal tuner on all four bands. 2. Has enough metal in the air to provide adequate microvolts to the RX - to make it function well without being overloaded. 3. Provides some gain - or at least a clean predictable pattern 4. Is light, compact and easy to deploy. My inkling is that a normal Carolina Windom may be the thing. I'll work on developing a micro-QRP version. What doesn't work? Classic G5RV (102 Ft) - will not load on any band with tuner. Offset-Zepp fed with Coax (75'x25') What say guys? Anybody have superb luck with an antenna yet? Bob-AB5N __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] We need to develop the Ideal Antenna!
I've had seemingly good results with my KX1 on 20, 30, and 40 just using the 25 ft wire thrown into a tree and a 16 ft counterpoise along the ground. The KXAT1 found useable matches every time. It seems like I remember doing OK on 80 meters too, but that may have been into my 6BTV vertical at home. If I'm out during the day and happy with 20 meters only, I use an End-Fedz 20 meter half wave antenna and no counterpoise, and it works well for me with the KXAT1 turned off. Good luck! Chip On Fri, May 13, 2011 at 1:17 PM, Don Wilhelm w3...@embarqmail.com wrote: Bob, Actually, a properly functioning KX1 has an MDS of better than -130 dBm, so it actually is a sensitive receiver. Some like the Carolina Windom, but I don't like any unbalanced antennas, and have a high preference for center fed antennas, they are easier to tame, and if the feedline leaves the antenna at right angles from the center, seldom do RF-in-the-shack problems emerge. The KXAT1 has a more limited range on 80 meters than the other bands just because the total inductance and capacitance is limited - only 3 choices of each. I would suggest a trap antenna with traps for 40 and 20 meters. Feed it with balanced feedline cut a half wavelength (or multiple) on 80 meters - the tuner should be able to match it on 30 meters and the half wavelength of feedline on 80 meters should present a feedpoint impedance close to that at the antenna center (50 to 75 ohms) for 80, 40, and 20 (assuming the traps are used). I have not actually built such an antenna, but the theory says it should work just fine. Keep the balanced feedline supported along its entire length and don't forget that there is a velocity factor to consider when determining a half wavelength - if you cannot do that, add a trap for 30 meters and feed it with any length of coax. Coaxial traps are not difficult to build, and for QRP use, can even use RG174 on a piece of 1/2 inch PVC for a form. Doug DeMaw (SK) W1FB had information on building traps like that in QST a very long time ago (try in the 1980s). Also see the W1FB Antenna Notebook and/or the article in QST for Decenber 1984 page 37 by N4UU. Gary o'Neil N3GO also has some good information about coaxial traps on the web (use Google). I realize that a 135 foot long antenna is not easy to deploy, so I would suggest an alternative - build a coax fed trap antenna for 40, 30 and 20 meters (traps for 30 and 20), and carry along 2 33 foot lengths of wire - insulators on one end and an alligator clip on the other - when you want to operate 80 meters, add the wires to each end of the radiator. You could carry that concept a bit further, and build the antenna for 20 meters with no traps and then add a set wires for use on 30 meters, another set of wires for 40, and yet another set for 80. clip on the wires for whichever band you want to operate. That is my nickel's worth. 73, Don W3FPR On 5/13/2011 1:31 PM, AB5N wrote: Hi Guys- Well, I'm in week two of enjoyment with my new KX-1. I did have a few problems in assembling, but that is history. This little rig has a simple receiver which has only half the sensitivity of a usual radio. As well, we are dealing with 3-4 watts TX out max. We have to have an excellent antenna. I've tried the suggested 25 ft. long wire with radials. Ah, it's not good enough. I even got some strange RX-feedback internally at some frequencies using it. I believe the criteria for an excellent antenna will be as follows: 1. Will match up well using the internal tuner on all four bands. 2. Has enough metal in the air to provide adequate microvolts to the RX - to make it function well without being overloaded. 3. Provides some gain - or at least a clean predictable pattern 4. Is light, compact and easy to deploy. My inkling is that a normal Carolina Windom may be the thing. I'll work on developing a micro-QRP version. What doesn't work? Classic G5RV (102 Ft) - will not load on any band with tuner. Offset-Zepp fed with Coax (75'x25') What say guys? Anybody have superb luck with an antenna yet? Bob-AB5N __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
