![]() 5 ft 11 1/2 inches is a 1/4 wave at 27.205 middle of cb channels So multiply 246 by the Velocity Factor of the coax, Then divide by the frequency. To determine the length to use, Use this formula "Length in feet = 246 x VF / Freq in Mhz" VF = the Velocity Factor of the coax. The length of the 75 ohm coax is most important. Ĭonnect the shield of a "Short Piece" of 75 ohm coax to one end of the loop antenna, Connect the center of the 75 ohm coax to the other end of the loop antenna. You should have added a 1/4 wave matching stub of rg 59 or rg 11 coax at the antenna and would have gotten a low swr. The propagation is basically straight up and down on 80 meters, and the loop is an awesome performer for me up close and out to however far the band is working, usually several hundred miles (several states out.)Īctually a Full Wave loop will have approx 2 db gain over a dipole antenna depending if its a circular, 4 sided quad or 3 sided diamond configuration. Loops do increase in gain as you increase in frequency, and they are great multiple-band antennas, so my loop for 80 meters has more gain and works well on 40, 20, 17, 15 meters ect.as well as working very well on 80 meters too even without any gain. An Antron 99 or a simple dipole would kick its ass. It will radiate just fine with no SWR, but will be a no-gain antenna. However, loops have no gain at the cut frequency. You can make one cut just for CB, total length around 36 feet. It also serves as my "flatside" antenna for 10-11 meters. Almost all of my HF work is on a horizontal loop cut for 80 meters. Very famous antenna that's been around for a long time. The full wave antenna that does work is the Loop, sometimes called a Loop Skywire. As stated above, the electrical math isn't right for a full wave dipole. ![]() Well there is ONE full wave antenna for any frequency, but it's not a vertical type or a dipole configuration. You know, a 1/2 wave is better than a 1/4 wave. I would like to build a small tuner for it just to see how it would compare to a half wave dipole in the yard.Īlthough to the untrained ear, the idea of a full wave antenna sounds great. perhaps since it had the appearance of no carrier it sounded all crappy and wooshy and swingy to the reciever. it made my signal lose all its carrier and on the recieving end it was all swingy. I had mixed results, it was way more narrow than I expected, perhaps because it was so low to the ground. anyway I didnt care becasue I didnt have a tuner and apparently if you read the manual Galaxy says its saturn base can run into a 2:1 swr indefinetely with no ill effects (read the manual, Im not lying). high by cb standards for hamsters it was perfectly acceptable, over 2:1 maybe, I really cant remember. it had a high swr with no matching device. off the ground and just about stretched across the yard suspended from pcv insulators from tree branches made of solid #10awg. YEARS ans YEARS ago I made a full wave wave dipole for 11m.
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