The same would hold true for elevated radials? I am designing a 4-square for 80m. Full size verticals. Comteq phasing/switching unit. But I need elevated radials for practical reasons (the land below
Elevated radials are overrated. Unless you can get them up 1/4 wl or more in the air, you will still contend with ground losses when you only use a few radials. Also the system is NOT fully unbalanc
No. Well... the advice of the more radials the better is sound, but when you start looking for resonant lengths, etc. it gets much trickier. When they were validating NEC-4, a fair amount of research
I do not agree on the elevated radials as being overrated, for Arizona desert anyway. I had my 40m 4sq installed with 8 buried radials under each element. The tuning method for the array was to erect
I use 4 elevated radials under each element on my 4 squares for 40m and 80m with Comtek box and am very happy with the performance of both systems. W1XT (a near neighbor) prefered 8 elevated radials
for Arizona radials under each elements power went into little Kentucky equal) to the desired where the wasted with the array's Everyone pretty much knows eight buried radials can be somewhat lossy.
Tom, 1) In your opinion where is the cutoff between "elevated radials" and a "ground plane" system. How high off the ground does the system need to be before it becomes a GP rather than an "elevated
First, absolutely the least reliable model is one used when a wire is parallel with and close to earth. That's pretty well established. Second, most of the work available to us simply involves models
Comments interspersed... I think you might find some dispute there, as far as the modeling code itself goes. I would state it as: The model results will be unreliable without a good description of th
Tom, What kind of A/B FS comparison could be done by disconnecting radials that already lay on the ground under the vertical, for example with a large relay?? Say you have 50 radials spread out, and
No, because the radials are still there, and interact with the field. Interestingly, one of the validation cases for NEC-3 (which supports buried structures) was whether a buried wire could be detect
phasing/switching unit. But I need elevated radials I am not sure how many and how long only one with decent results. Perhaps I missed some previous messages in this thread? In reading the above I c
Tom - W8JI, As always Tom thanks for your clear explanations. You often plug the gaps that are left by some of the mainstream printed publications. 73 Patrick ________________________________________
Thanks Jim! Your response tells me that even though radials are spread out under the vertical they need not be connected to have influence on the pattern. But surely there must be a substantial diffe
I don't think you missed anything Paul. If we know points of diminishing returns and the real cost of not doing something, we make better decisions. For example, did you know that if you use an elev
out under the the pattern. But performance between having Peter, In the nearfield many complex things interact. It is pretty much unpredictable without knowing everything and doing a great deal of w
having Sure, there's a difference. The real problem is that it's very difficult to determine what the difference is. And, whether it is "substantial". They did a bunch of tests back in the 80's with
counterpoise the radials all radiate substantial less problem that is? Or did you think I want the radials to radiate. I kinda liken each element as a half wave dipole with one end of the dipole in
Author: "VE6JY Don Moman" <ve6jy@freenet.edmonton.ab.ca>
Date: Mon, 25 Oct 2004 00:41:03 -0000
I'm asking a couple of questions for a friend for whom I've been passing along portions of this thread to, and who is involved in getting a 80m 4sq up and running. Test equipment is limited. He's usi
Specifically, how are the vertical radiators isolated from the 1/4 wave 75 ohm feeders? There isn't enough spare coax to wind a choke. Buried 3/4 wave feeders and a coax choke? How many turns is "eno