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#1
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![]() "Cecil Moore" wrote That's what antenna modeling programs are for. ---------------------------------------------------------------------- Cec, You should realise it's a waste of time pointing people towards computer programs which require a 6-weeks full-time training course to understand what its all about. And which they don't possess anyway. Especially when a few sentences of plain English can provide an adequate explanation to the enquirer. ---- Regards, Reg. |
#2
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![]() Reg Edwards wrote: "Cecil Moore" wrote That's what antenna modeling programs are for. ---------------------------------------------------------------------- Cec, You should realise it's a waste of time pointing people towards computer programs which require a 6-weeks full-time training course to understand what its all about. And which they don't possess anyway. Especially when a few sentences of plain English can provide an adequate explanation to the enquirer. ---- Regards, Reg. Hi Reg., The question was certaintly not a few sentences of plain English. If the enquirer had shortened his description to a few well defined sentences he might have some answers by now. The demo version of EZNEC is free, as are your programs. Niether require 6 weeks to learn. My advice is to model the antenna, or give more precise question(s). Gary N4AST |
#3
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Reg Edwards wrote:
Cec, You should realise it's a waste of time pointing people towards computer programs which require a 6-weeks full-time training course to understand what its all about. Reg, if I can learn ELNEC in two years, anyone can do it. :-) -- 73, Cecil http://www.qsl.net/w5dxp |
#4
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I guess that an old man who hasn't been into electronics very long.
But, I do possess a fair amount of common sense. I can see that you guys can't or won't help me figure out my problem. Too many issues here. Everyone has SOME area of excellence. I just haven't found the right person who WILL help. Life is filled with people who can only see their way. Words are not as powerful as IDEAS. Thanks for the "words", fellas. |
#5
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Paladin wrote:
I guess that an old man who hasn't been into electronics very long. But, I do possess a fair amount of common sense. I can see that you guys can't or won't help me figure out my problem. Too many issues here. Everyone has SOME area of excellence. I just haven't found the right person who WILL help. Life is filled with people who can only see their way. Words are not as powerful as IDEAS. Thanks for the "words", fellas. I think there are people willing to help but from your original posting, there was not enough information for me to model your antenna. I don't recall you even telling us the length of your inv-V dipole. And what did you mean by "linear loaded"? -- 73, Cecil http://www.qsl.net/w5dxp |
#6
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The elements are "linear-loaded" . They are folded back on
themselves. The phsical length is 70ft.,But the electrical length is 210ft. long ! Now, is this strange dipole a 140ft. long,OR is it 420ft. long ? ? That's why the feedline is so much problem............I've built over 2 doz. antennas;this one IS tricky ! I have only 1/8 acre of land; Hence the problems with dipole lengths,and feedline lengths.....:-) |
#7
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Paladin wrote:
The elements are "linear-loaded". They are folded back on themselves. The phsical length is 70ft.,But the electrical length is 210ft. long Something like this? (fixed font) 35' 35' -------------------------+ +------------------------- | | +------------------------+ +------------------------+ | | +------------------------+ +------------------------+ | | | | | | feedline How far apart are the adjacent wires spaced? -- 73, Cecil http://www.qsl.net/w5dxp |
#8
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The wires are close. The builder used rotor feed line. 3 equal
lengths of wires 70ft. long THAT make one element. there is one on the oppisite side. |
#9
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Paladin wrote:
"I just haven`t found the right person who will help." Help, it seems, is the answer Paladin wants to hear. When you want to put 8 pounds of crap in a 4-pound bag, life is often that way. You quickly run out of good advice. When a respondent says there`s no computer program to tell you how to linearly-load an antenna wire, you are invited to prove him wrong. The ARRL Antenna Book says: "Since the dimensions and spacing of linear-loading devices vary greatly from one antenna to another, the best way to employ this technique is to try a length of conductor 10% to 20% longer than the difference between the shortened antenna and the full-size dimension for the linear-loading device. Then use te "cut-anhd-try" method, varying both the spacing and length of the loading device to optimize the match." You might write a program for that. Best regards, Richard Harrison, KB5WZI |
#10
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![]() "Cecil Moore" wrote Reg Edwards wrote: Cec, You should realise it's a waste of time pointing people towards computer programs which require a 6-weeks full-time training course to understand what its all about. Reg, if I can learn ELNEC in two years, anyone can do it. :-) ==================================== Cec, What is ELNEC? OK, I can guess! Quite truthfully, if you had pointed ME towards EZNEC then I am unable even to download and un-zip it. Acually, I do have a copy. Some years back Roy took pity on me and, without any request from me, very kindly broke the rules and airmailed me a free parcel of 3.25" floppy disks. It took me a week to print out the instruction handbook and another 2 weeks just to read it by which time I had forgotten what the problem was. 'Experts' should realise, from the manner in which questions are written, the predicament some questioners are in and make allowances instead of leaving them to flounder about in a sea of frustration and despondency. N4AST's comments are unworthy. ---- Regards, Reg. |