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On Mon, 31 Jan 2005 08:42:30 -0600, Cecil Moore
wrote: Buck wrote: This is the antenna I want to copy before I start experimenting: http://hamcall.net/6bandmegpole.html Hi Buck, they don't give exact building information as far as I can tell. Here's what they say: Inverted V with the center at 32 ft and ends at 8 ft. Approximately 135 ft long fed with 100 ft of RG-213. Why 32 ft with the ends at 8 ft? Because that is the configuration that gives the advertised values of SWR. Why 100 ft of RG-213? Because the losses in the coax results in the advertised values of SWR. If you deviate from their configuration including having different ground conditions, you will, no doubt, need an antenna tuner for some bands. They have probably fine tuned their configuration so they can make their claims which you probably will not be able to duplicate. I don't want to discourage your experimentation - just make a prediction based on experience. If you really want an efficient all-eight-HF-band antenna requiring no tuner, you can find one on my web page at http://www.qsl.net/w5dxp/notuner.htm If you don't want to go to the trouble of varying the length of your feedline, you can at least learn what you are up against in your quest. thanks, Cecil. I have looked at that before. ( Not to argue with you, but I considered your feedline switches a form of tuner, just not conventional ![]() That is definitely a great looking antenna. I am glad you pointed out the precision needed on the OCF I was looking at. What I am working towards is a great all-band antenna that can be easily ported and setup and used without switching (kind of like the T2FD) and no unique parts required. I am glad to meet you (and know who you are.) To be honest, I have spent a lot of time on your site. At one time, I could have answered many questions about your antenna without looking at it. Your site is the first place I saw the ferrite beads on the feedline for a choke and I have investigated them in depth since then too. One thing I didn't find about the antenna was the bandwidth of 40/80 meters or an SWR chart for each band. (I realize that you might not be able to do that easily, I'm just stating an observation.) Also, in addition to the antenna I mentioned to you (It was only one of several OCF's I am looking at), it seems to be common for OCF antennas to use 6:1 baluns. Some do use 4:1 and most, regardless of the balun, require a tuner. I have several ideas that I am kicking around so being able to easily be able to build an inexpensive balun at different ratios will come in very handy for my experiments. Before the internet there were books. The best one could hope for was to see a picture of the author on the cover, but now, after all these years, I am still amazed when I find myself in conversation what use to be ... the untouchables. ![]() It was great to meet you. Thanks for replying. Buck. -- 73 for now Buck N4PGW |
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