Hi Gang, I'd like to toss in my two cents worth on the subject... Two years ago, I was with a group of QRP'ers who built a top loaded 2 el 80M phased vertical array, with hopes of making a 250mW two-
It won't get the job done even if the base of the antenna is OVER the salt water. Salt water is not copper. It is a few hundred times better than good dirt, that's all. Maybe, maybe not. What were c
Thanks for the info Paul, I suspect that in all mentioned cases you are talking about radials on the ground. Your experiences confirm what would be expected (surprise). Was any comparison done with e
Hi Yuri and all, Another long and never ending thread, radials! I might bail out of this tar-baby on this one. Fact Yuri. When the radials are less than .025 to .05 wl apart at the open ends, they lo
.... snippydyduda Thanks for elaborate answer Tom, I know all that. I haven't seen the figures answering my question. I can interpolate and guess too and have EZNEZ to "design" antennas on the paper.
K8CFU et al. found experimentally that folded unipole gave them "surprisingly higher signal levels than expected and than simple radiator." Using folded unipole you get wider bandwidth and by playing
Hmm. 1/4 wave radials means a circle of 1/2 diameter. That's a perimeter of pi/2 wavelength, which divided by .05 yeilds about 31 radials. Similarly, .025 spacing at the ends is about 63 radials. If
Hi all - The traditional broadcast radial field has 120 radials because the radials go out to 0.4 wavelengths, not 0.25. BTW, if one would like the radials to behave like a solid screen, 0.015 wavele
Hi Bill, Good observation Bill. You hear that because people are parroting the FCC requirement, which is based on "twice as much as near-perfect is good enough". The FCC not only wants a system to wo
Space between radials has to be equal or less than .025 WL. The tables consider .5WL radials and this numbers lead to the famous 120 radials (>90% efficiency). Unless the radiator is longer than 1/4
You could just put a "fork" in the radial splitting it into two at that point by adding a second wire as well. -- 73 es God Bless de KK1L...ron (kk1l@arrl.net) <>< QTH: Jericho, Vermont My page: htt
Now that is a handy observation and helpful formula. It is based on Tom's point that the perimeter separation need be no more than .025 to .05 wavelength for 1/4 wave radials. Now the question for mo
Author: Michael Tope" <W4EF@dellroy.com (Michael Tope)
Date: Thu, 11 Jan 2001 19:58:18 -0800
Heres one for all you radial efficiandos. I am involved with a site (workplace club station) where the antennas sit near the edge of a 400 foot mesa. The mesa drops off in the direction of our longpa
Hmm. 0.4 * 2 * pi / 0.025 = about a 100, not 120. If you keep the 0.025 wavelength spacing at the perimeter, you have to go out to nearly 0.5 wavelength radials to require 120 radials. For 1/4 wave r
That's NOT what Tom said. He was saying that radial spacing closer than about 0.025 wavelength is virtually indistinguishable from a solid sheet of metal. That doesn't meant that short radials can so
Mike, K6STI's TA program can answer all your questions and save you a lot of time and trouble on which system will give you the best results. I believe Brian still sells the program. I've found it to
Have to add my two cents here based on five years of ocean/bay-front operating. In preparing for Field Day when I first moved here to Casey Key Island, Florida, I conducted some antenna tests running
Author: Michael Tope" <W4EF@dellroy.com (Michael Tope)
Date: Fri, 12 Jan 2001 03:31:41 -0800
Hey Tom, Yes, I should have mentioned the station is just Northeast of the LA basin in the foothills of the mountains. There is another set of hills about 1 or 2 miles south of the Mesa (approximatel
The questions posed below have been around for a LONG time. In fact, an extensive study was conducted and published in the June 1937 edition of the Proceedings of the IRE (Institute of Radio Engineer