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found this post on another forum and thought someone might find it interesting:



"some old 5/8 wave antenna lengths from ads in S9 magazine, CB magazine, Echo catalog, Henshaws catalog, & from CB Radio Operators Guide 2nd Edition by Tab Books; all from the 70's"

Avanti Saturn (22' 6")

Avanti Sigma 5/8 (22')

Hygain CLR2 (19' 10")

Hygain Super CLR Penetrator (22' 9 1/2")

Kris GLR-2 (19' 10")

Mark Products MK-V (20')

Mosley Electronics Devant (20' 5")

New-Tronics PRO-27-JR (19" 10 3/4")

R. Shack Archer Deluxe Colinear (19' 10")

Wilson Alpha V 5/8 (21')


(and one .64 wavelength)

Taylor Grand Slammer 6400 (23' 3 1/2")

__________________
"Man shall never reach the moon, for such a quantity of gunpowder would be needed as to gravely injure the crew."
~ Children's Encyclopedia, 1926

1

thank you for the information i will be tuning this for 27.475 so i know it will probably be under 23 slightly.i tend to bounce between 27.385 and 27.555 and the maco length now is about 19 ft.i will take this down this evening and set it up on a pole,starting at 23 feet then adjusting my tap point.if i cant getter down ill go back to radiator.i might just take my radio,meter and headphones out to the yard also as close to the antenna as i can for fine tuning.this antenna full length is close to 21 ft so maybe i will get lucky with tuning part.

ok well so far i managed to get 27.555 down to 1.5 and 38 1.3 but man this thing is touchy and the match either way goes up fast very fast.i lost the broadbandedness but still working on it!the height now is 21-10 inches,when i took it down i measured it to see and it was 20-10 1/2.at least i am still longer right.i ended up moving the grounplanes down to the bracket making them 3-4 inches below the loop,this helped swr.the loop gap is at 3 inches i dont know if this really helped or just made the tap point move.i have a feeling that i will need to construct another loop bigger/smaller or with more turns not sure on this.i have some copper tubing 3-4 feet that the tap would fit right on but i will save that for last hoping for more input here.any suggestions welcome i am going to take another stab at it now!73s

did you not run a ground wire also since that could be used by the antenna as a element also ?
got any closer pics of the matching system used ??????????

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good idea booty i will post some pictures shortly!

no ground wire hooked to mast-mast in the ground.

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insulator.update i took the extra small radiator out of the antenna and managed to get the regular antenna to stretch out to the same 22-10 inches results are 27.555-1.3,27.385-1.3,dip in the middle but still not broadbanded still working on it!PS-w5lz thanks for all your help,i hope i am not being a pain in the but i bet you have answered many of my questions a 100*before.

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1342,

i think you need to start keeping a chart of your SWR curves, and also the least amount of reflected power as you make your adjustments.

like, pick a length for the radiator, starting with the shortest length you think should work well.

then move the wire all the way to one side of the tuning ring.

test the SWR at the top, middle and bottom of the freq range you are tuning for, at the same time make a note of the percentage of reflected power you are getting.

draw the SWR curve on a piece of paper.

now move the wire about an inch on the tuning ring.

make another chart.

keep going all the way around the tuning ring at this length, charting all the way around.

now increase the length by 3", or 6" or whatever you think is best, move the wire to the same starting point on the tuning ring you used before and do another set of charts all the way around the ring, noting the reflected power along the way.

if you keep doing this until you get past the max length that you think should work well, you will have a nice piece of data to ponder over without having to go outside.

after looking at the charts over and over for a while, you will get a picture in your head of where that magic spot is that is a combination of bandwidth, low SWR and small percentage of reflected power.

yes, this seems extremely tedious, but in my experience, trial and error can leave you sleepless at night trying to remember whether or not you tried everything.

oh, and you are removing that ladder when you go inside to do your SWR readings right?! LOL J/K!

good luck with it, im anxious to see what you find out as i plan on buying one of these antennas sometime this year.
LC

__________________
"Man shall never reach the moon, for such a quantity of gunpowder would be needed as to gravely injure the crew."
~ Children's Encyclopedia, 1926

loose cannon i am getting closer and got more pics.so far i have a length of either 21-1/2 inch radiator or 21-9 1/2 inches entire length with the dip at 32 and 1.15 and 38 at 1.2 and 55 at 1.3 maco states to measure the full length from top to bottom.the loop gap is still at 3 inches maco calls for 1 inch.groundplanes are 3 inches maco calls for 1/2 inch from bracket.changes so far are as follows, drilled rivets out of pl-259 and replaced with nuts and bolts,changed crappy wire to 12 gauge double insulated copper(should help when it rains)also increased the length of this tap wire by one inch just in case i have to make a bigger loop,better connector for the tap and a gromet over the pl-259 connector(no more rain there haha).

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