Short top loaded vertical dipole, the DX king
A few nights ago about 2.00 AM AST, 06.00 UTC, I passed through my radio operating room and could not resist the temptation to turn on the TS-940SAT and tune across the 80-meter DX window. There was a solitary G station calling CQ DX for North America. He was just on S-9 and I figured that he was either not beaming to the Caribbean, or he was not one of the big power stations like Alpha Mike Norway. Most G stations seem to run 4-square or some sort of vertical beam antenna, and would usually push my S-meter well into the red. Since no one on this side of the ocean responded to the G station's repeated calls I decided to give him a short call. All of a sudden the frequency went crazy with signals and I could not hear the G station come back. A few minutes later there were 14 calls in the logbook including some Italian stations, G stations, 9A3 and 9A4, with most them trying to break off my meter. I pulled the plug on the mini-pileup and went to bed to dream about how I could work 80-meter DX nightly, without depriving my body of its much deserved rest.
I have been ham radio operating for over 40 years and I have never been able to get hams across the ocean to put my S-meter so far in the red zone until I experimented with a short vertical dipole antenna. Being short has nothing to do with the antenna's performance, because you cannot see the -0.5dB difference between the short and full sized vertical dipole antennas on your S-meter. Neither can you hear any difference in the loudspeaker.
I have been using the Kenwood TS-940SAT since 1995 with various antennas, so I can really appreciate the difference made by the short vertical dipole, especially on this sunspot cycle curve. For the last couple years I have searched for another simple uncomplicated vertical antenna that can do better than this short home brew vertical dipole, but I have been unable to find even one. I now make it my mission to promote the 'short loaded vertical dipole' antenna. I firmly believe this antenna is the solution that many hams need in these times as it can help them to meet and overcome a few of the Dx-ing challenges they now face. Speaking personally it has done just that for me, and I believe that there may be a few ham operators somewhere on the planet in a similar situation like mine.
I need to work DX consistently on 40 and 80 meters but only have space for one quarter wave ground radial, maybe 2 radials if I agree to some sort of cock-eyed orientation. It is said that 4 to 6 elevated radials may rival the performance of the 60-120 ground radials, but 4 elevated radials is more than too much for my small city lot. Even if I had the space, given the global economic situation, I would think hard and long before throwing $300 to $600 uncle Sam after a ready made vertical antenna system, but of course, if it was a steal on eBay, I could be tempted. I use the words 'throwing' rather than 'invest in' because the ham radio hobby is just that, a ham radio hobby, and we should never loose sight of that, under any circumstance.
There would always be some hams who are unaffected by the state of their national economy, but if they do not use the right antenna for working DX consistently on 80 and 40, they will be just like the rest of us who are struggling to be heard on the other side of the ocean. You only need the correct tools for the job, and it does not matter if the tools have a gold edge to it or not. It it is like the PL-259 coax plug. I am yet to experience the difference working DX on 80-meters using a gold and silver plated $8.00 PL-259 and the "El cheapo" nickel plug for only 99 cents. On the lighter side though, you never know when you may need to consider using the gold4cash service, so maybe those gold tipped PL-259 plugs could look like an investment.
So the ham operator in Timbuktu, [please, no offense is meant to anyone in TZ], who may want to work 40 and 80-meter DX consistently but don't want to shin out the green stamps to send across the ocean to the cousin in the US to get his ready made DX antenna, does not have to be unduly alarmed because he knows that he can fabricate that $600K antenna for pennies if he really wants to. Where there is a will, there is usually a way. The Internet reaches into some places which we cannot fathom, and people in some very remote places on this planet have Internet and call phones, and can no longer be considered as being "behind God's back". As a matter of fact, no such place exist on the face of the planet today. Resourcefulness, creativity and innovation are available to all hams who are serious about working DX without breaking the bank.
All hams have read about the vertical dipole antenna in one handbook or another. For some reason unknown to me, there seems to be more information and propaganda associated with HF horizontal antennas, which are usually for 20, 15 and 10-meters. For many hams this is where the fun starts, and making DX contacts are relatively easy when there is propagation. Some hams never venture below 20 meters, and when they do it is with a G5RV or some variation of single band or multi band drooping dipole. Most of us have been there, and some of us get stuck there, but the more adventurous among us want to acquire and maintain a certain level of DX working consistency, which points us in the direction of a sensible antenna system. A real 40-meter horizontal antenna is twice as larger as a 20-meter antenna. Few of us have the capability for installing one of these 40 or 80 meter monstrosities on our property, if the government will allow it.
Sometimes I really feel it for our ham radio brother and sisters in countries where regulations prohibit them from using antennas that would augment their ham radio experience. Those of us in less developed or developing countries are not plagued with these regulations as yet, so let us enjoy building and using our ideal DX antenna while we can. I will not encourage any ham to break the law, but the short loaded vertical dipole antenna seems to have exploitable stealth-ability.
If you want to work DX on the low bands the logical antenna to use is a vertical with no less than 120 ground radials. If you have limitations and cannot get the 120 radials, try for 60 radials, and worst case 16 radials. If you are like me and can only make 1 good radial which is totally unacceptable, you have to look for the alternative to radials and counterpoise. Enter the vertical dipole. First problem, it is to long. Solution, make it shorter. Result, it is not working right. Solution, use the correct configuration, top and bottom loading. Read all about it on the Internet, join our verticals2 yahoo group and talk to other vertical antenna experimenters.
Something that I have found to be critical to my short loaded vertical dipole antenna's performance is feeding the antenna with a solenoid balun. If you are unfamiliar with this balun check it out here. The only other balun I use is made up with Teflon coax cable and ferrite beads. The ferrite bead balun works after a fashion because I can see the result, but the solenoid balun is significantly more effective, like chalk and cheese, and I encourage hams to try the solenoid balun on their vertical antennas. I would go even further and encourage hams to put a solenoid balun on all their HF antennas. For me it is not about style and looks, it is about getting the ultimate in technical performance.
Recently I lost a balun price argument to one of the V4 ham brothers, who has proven to me that the solenoid balun is rather more expensive, than his air core balun on a shellac treated cardboard toilet tissue paper tube. We have not tested the home brew solenoid balun and the "toilet" paper roll balun products side by side, but I am confident that the solenoid will win hands down, every time. I cannot see why the solenoid balun has to be 'expensive' with the miles of coax cable thrown away at the landfill by the local cable TV company, but of course, this is just my viewpoint.
So what's up with your low band DX antenna? Are you missing out on the low band DX action?
[To be cotinued]
I have been ham radio operating for over 40 years and I have never been able to get hams across the ocean to put my S-meter so far in the red zone until I experimented with a short vertical dipole antenna. Being short has nothing to do with the antenna's performance, because you cannot see the -0.5dB difference between the short and full sized vertical dipole antennas on your S-meter. Neither can you hear any difference in the loudspeaker.
I have been using the Kenwood TS-940SAT since 1995 with various antennas, so I can really appreciate the difference made by the short vertical dipole, especially on this sunspot cycle curve. For the last couple years I have searched for another simple uncomplicated vertical antenna that can do better than this short home brew vertical dipole, but I have been unable to find even one. I now make it my mission to promote the 'short loaded vertical dipole' antenna. I firmly believe this antenna is the solution that many hams need in these times as it can help them to meet and overcome a few of the Dx-ing challenges they now face. Speaking personally it has done just that for me, and I believe that there may be a few ham operators somewhere on the planet in a similar situation like mine.
I need to work DX consistently on 40 and 80 meters but only have space for one quarter wave ground radial, maybe 2 radials if I agree to some sort of cock-eyed orientation. It is said that 4 to 6 elevated radials may rival the performance of the 60-120 ground radials, but 4 elevated radials is more than too much for my small city lot. Even if I had the space, given the global economic situation, I would think hard and long before throwing $300 to $600 uncle Sam after a ready made vertical antenna system, but of course, if it was a steal on eBay, I could be tempted. I use the words 'throwing' rather than 'invest in' because the ham radio hobby is just that, a ham radio hobby, and we should never loose sight of that, under any circumstance.
There would always be some hams who are unaffected by the state of their national economy, but if they do not use the right antenna for working DX consistently on 80 and 40, they will be just like the rest of us who are struggling to be heard on the other side of the ocean. You only need the correct tools for the job, and it does not matter if the tools have a gold edge to it or not. It it is like the PL-259 coax plug. I am yet to experience the difference working DX on 80-meters using a gold and silver plated $8.00 PL-259 and the "El cheapo" nickel plug for only 99 cents. On the lighter side though, you never know when you may need to consider using the gold4cash service, so maybe those gold tipped PL-259 plugs could look like an investment.
So the ham operator in Timbuktu, [please, no offense is meant to anyone in TZ], who may want to work 40 and 80-meter DX consistently but don't want to shin out the green stamps to send across the ocean to the cousin in the US to get his ready made DX antenna, does not have to be unduly alarmed because he knows that he can fabricate that $600K antenna for pennies if he really wants to. Where there is a will, there is usually a way. The Internet reaches into some places which we cannot fathom, and people in some very remote places on this planet have Internet and call phones, and can no longer be considered as being "behind God's back". As a matter of fact, no such place exist on the face of the planet today. Resourcefulness, creativity and innovation are available to all hams who are serious about working DX without breaking the bank.
All hams have read about the vertical dipole antenna in one handbook or another. For some reason unknown to me, there seems to be more information and propaganda associated with HF horizontal antennas, which are usually for 20, 15 and 10-meters. For many hams this is where the fun starts, and making DX contacts are relatively easy when there is propagation. Some hams never venture below 20 meters, and when they do it is with a G5RV or some variation of single band or multi band drooping dipole. Most of us have been there, and some of us get stuck there, but the more adventurous among us want to acquire and maintain a certain level of DX working consistency, which points us in the direction of a sensible antenna system. A real 40-meter horizontal antenna is twice as larger as a 20-meter antenna. Few of us have the capability for installing one of these 40 or 80 meter monstrosities on our property, if the government will allow it.
Sometimes I really feel it for our ham radio brother and sisters in countries where regulations prohibit them from using antennas that would augment their ham radio experience. Those of us in less developed or developing countries are not plagued with these regulations as yet, so let us enjoy building and using our ideal DX antenna while we can. I will not encourage any ham to break the law, but the short loaded vertical dipole antenna seems to have exploitable stealth-ability.
If you want to work DX on the low bands the logical antenna to use is a vertical with no less than 120 ground radials. If you have limitations and cannot get the 120 radials, try for 60 radials, and worst case 16 radials. If you are like me and can only make 1 good radial which is totally unacceptable, you have to look for the alternative to radials and counterpoise. Enter the vertical dipole. First problem, it is to long. Solution, make it shorter. Result, it is not working right. Solution, use the correct configuration, top and bottom loading. Read all about it on the Internet, join our verticals2 yahoo group and talk to other vertical antenna experimenters.
Something that I have found to be critical to my short loaded vertical dipole antenna's performance is feeding the antenna with a solenoid balun. If you are unfamiliar with this balun check it out here. The only other balun I use is made up with Teflon coax cable and ferrite beads. The ferrite bead balun works after a fashion because I can see the result, but the solenoid balun is significantly more effective, like chalk and cheese, and I encourage hams to try the solenoid balun on their vertical antennas. I would go even further and encourage hams to put a solenoid balun on all their HF antennas. For me it is not about style and looks, it is about getting the ultimate in technical performance.
Recently I lost a balun price argument to one of the V4 ham brothers, who has proven to me that the solenoid balun is rather more expensive, than his air core balun on a shellac treated cardboard toilet tissue paper tube. We have not tested the home brew solenoid balun and the "toilet" paper roll balun products side by side, but I am confident that the solenoid will win hands down, every time. I cannot see why the solenoid balun has to be 'expensive' with the miles of coax cable thrown away at the landfill by the local cable TV company, but of course, this is just my viewpoint.
So what's up with your low band DX antenna? Are you missing out on the low band DX action?
[To be cotinued]
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