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#42
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![]() wrote in message oups.com... John Smith mentioned the Microvert antenna, which I know very well. I made an extensive comparison of the RoomCap (hb9abx) against Microvert, and was using the best Microvert available (MV-500) for 40m. Test at same location, both antennas at same height in A-B configaration. Test was performed by many rapid changes between the two antennas, and the remote station was observing the signal strength. Result was, that the RoomCap was 2 s-points stronger in average, in receiption as well as in transmission. Rember that 2 s-points correspond to 12 dB. A very clear result. 73s Felix HB9ABX Its my understanding the microvert is the HF equivalent of a "rubber duck" antenna. |
#43
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Jimmie D wrote:
... Its my understanding the microvert is the HF equivalent of a "rubber duck" antenna. Microvert is certainly no full wave dipole, but for stealth they are great. Motorhomes, camping, fishing, trailer courts, beaches, parks, etc.--they attract little attention when disguised in a sun umbrella (doesn't have to be functional), badminton pole, flag, etc. Regards, JS |
#44
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![]() "John Smith" wrote in message ... And, yesterday I walked on water, in front of 12 witnesses. Fortunate for you, I made a video of this! If you go to my webpage you can purchase a high definition video in true color of this truly amazing feat of mine, for the most reasonable price of $29.95 USD! Click here to purchase this truly remarkable video--a real once in a lifetime opportunity: http://BridgeForSale.org Regards, JS Blasphemy ought to have a point -- and I had the misfortune to open this on Christmas Night. If you think the OP's assertions are bogus, maybe you should say why. (There's enough snot being slung around in this newsgroup for it to be declared an epidemic.) |
#45
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Sal M. Onella wrote:
Blasphemy ought to have a point -- and I had the misfortune to open this on Christmas Night. If you think the OP's assertions are bogus, maybe you should say why. (There's enough snot being slung around in this newsgroup for it to be declared an epidemic.) Very sorry you feel that way OM. Because your opinion matters to me, I have went to the time and expense of setting up a special support hotline for you. Just dial the following number: 1-800-call-mental-health The nice folks there can straighten everything out ... Regards, JS |
#46
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Let's come back to the subject here, the RoomCap
antenna: Read what wrote a builder of the antenna: Paul VE3UNF was answering my question, if his report is a joke, with the following reply: I am 60 years old - a retired airline pilot whom has flown all over the world from small turbo props, right up to the Boeing 747 with over 21,000.0 flying hours. I have been building antennas off and on now for 15 years at my various QTH's. Most of the antennas I have built came from various antenna books which were mainly stealth type antennas, as most of my past QTH's were in deed restricted locations. eg . attic antennas , hidden wire antennas, vertical antennas off of balconies, short dipoles with traps, the list goes on and on and I have never been able to make an antenna that for it's size can perform at all, or as well as, or outperform this G5RV. I moved to this location in Florida last year which has an acre and a half and was able to build this G5RV shortly thereafter. After reading up on your other antennas and now this antenna. I decided to build the RoomCap out of curiosity, -- just to see how well it performed -- in the chance that if it did give a reasonable account of itself, -- it would be beneficial to all those hams that I know, that cannot put up a very visible antenna -- as I remembered how difficult and frustrating it was for me to just get on the air when I was in Toronto. Well, I built it and I was pleasantly surprised. I am going to continue to test this antenna with the G5RV and keep recording the results irregardless of what anyone says. If any of these armchair electronic communiction antenna experts want to keep debunking it with their idea of the laws of physics without reading all your theories on it--Well so be it, with their ignorance . They obviously have thousands of dollars invested in their huge beams and don't care about the poor guys that have to live in deed restricted areas, who could greatly benefit from this. It would be great if they could keep an open mind and just start listening to some of the other reports that will be coming in from other builders. Like I said before, I have built many many small and large wire antennas only to have little to mediocre performance. Your antenna just blew me away with it's performance. Even though I am not an antenna expert - I know antenna performance when I see it. I don't care if it defies the laws of physics or you have come up with some new technological break through -- it bloody works and that's all there is to it . I really don't care if these so called experts don't believe us. They can just keep their ignoramist heads stuck in the sand and keep studying and memorizing the old formulas in their old physics books till they are blue in the face. Thanks , -- Paul VE3UNF ----------------------------------- John Smith wrote: Sal M. Onella wrote: Blasphemy ought to have a point -- and I had the misfortune to open this on ... Very sorry you feel that way OM. Because your opinion matters to me, I have went to the time and expense of setting up a special support hotline for you. ... JS |
#47
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RoomCap antenna and NEC
There is a large family of antanna simulation programs of NEC like EZNEC, MMANA, 4NEC2, NEC-2, NEC-4 etc. These programs can produce excellent results in designing and optimizing of beams and similar antennas. Personally, I made very good experience by optimizing the well known Spiderbeam. The results of the simulation proved to be fully correct in the practical field tests. However, there are many cases where the simulation with NEC programs is failing. You may obain results indicating efficency of over 100% ! This is not the discovery of a "perpetual motion machine", it is an error of computer simulation ..., or the results may become very inaccurate if there are varying diameters, different dielectricas etc. The NEC programs are designed primarilly for wire constructions and can be used for other constructions only under specific conditions. Regarding my RoomCap antenna the question was rised many times, how the NEC simulation would look like. Here I can say very simply: This construction can not be defined by the existing NEC programs. Especially the central element, the Varylink, can not be defined by NEC. Discussions with the well known NEC expert L. B. Cebik, W4RNL have revealed, that a way will be searched to include such elements in later editions of the programs. This example shows once more, that the usual way of antenna development with simulation, as is done mostly today, is a bad way, as finding of new constructions is prevented by the many limitations of the simulation programs. The programs are good at schools to show the students the behaving of changing parameters, but are not the way of the inventing engineer. To find new ways and concepts, one depends on the profound knowledge, the experience, and the mental force of the engineer, together with experimenting in the field. The computer is a very helpful tool in many aspects, but one may not expect much novelties by "experimenting" with simulation. At least not, until big improvements are made to these programs. Felix Meyer HB9ABX |
#48
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Felix wrote:
... The computer is a very helpful tool in many aspects, but one may not expect much novelties by "experimenting" with simulation. At least not, until big improvements are made to these programs. Felix Meyer HB9ABX All formulas were derived from "real hands-on" construction/development/experimenting. They will only be correct in the narrow confines of what has been built before, or closely related models to these physical antennas upon which the equations/formulas were derived from. Duh! JS |
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