KD3Y Posted March 18 Share Posted March 18 (edited) Elmers, I was considering making a 40 meter vertical portable antenna (using my tripod I got at Habitat for Humanity last year) for upcoming hurricane drill so I was reading up on HF verticals. I understand from my research that the radials should be the same length as the radiating vertical part of the antenna. Thats fine for something store-bought where all the parts are already pre-measured and cut to specs. But, I'm starting from scratch. See, I expect my antenna to be about 16 feet tall (give or take) and I wanted to make a slide-up-and-down section for tuning it. That worked great for my mobile antenna on my truck where it was grounded to the frame and I could just loosen the allen screw and slide the little tuning section up and down to lengthen or shorten it and get the SWR down. But on this particular antenna, if what I'm told is true, that would mean I'd have to assemble it to see the SWR, make an up or down adjustment to the vertical, then trim all the radials, then test it again, repeat, repeat, repeat. Seems to me that would be a lot of work to trim 30 radials each time I tested it. Then what if I need to lengthen it a tad? I have to go add wire to 30 radials? So my question is does the length of the radials matter that much or do they need to be the same length as the vertical, as I've read, sort of like a dipole needs to have both legs the same length for a good SWR? Why I question is that the 2 meter/440 mobile vertical antenna on my truck uses the truck body as the ground plane. But my truck is a lot wider/longer than the 4 foot or so vertical mobile antenna. So the "radial" for that antenna isn't the same legth as the antenna height. Thanks for you responses. I'm new to vertical HF antennas. 73 de Anthony, KD3Y Edited March 18 by KD3Y Link to comment Share on other sites More sharing options...
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