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Hello everyone. I am new to the forum and I’ve found reading many of the threads very interesting. I would like to know how to make a RF choke for my antenna. I am using a Imax 2000 on a lattice tower with no GP radials at the moment, this is going to change soon. How long should I make the choke coils and how many? Also I am in two minds with the GPK for the Imax, your thoughts on this would be appreciated though. The reason I’m in two minds over the GPK is because I'm also considering buying the interceptor 10K, and this antenna already has GP radials. I've also read with interest your idea's on insulating the antenna from the tower, so I’m also going to try this method out. Any help would be most welcome..

The size of the coil making up that choke should be such that there is no damage to the coax used to make that choke. Want to make that choke very symmetrical, wind it on a coil form, make it more 'pleasing'? Fine, do so. Rather just coil up a few turns of coax like you would a rope? Fine, do so. Think it would be easier to 'hide' if you wound that choke around the pole that holds up the antenna? That will work too. It really isn't all that critical. Back to the part about not deforming/destroying the coax used by bending it too much.
How many coils or turns in that choke? Depends on the frequency of use. 'More' is better than 'less' to some ridiculous extent. For 11 meters, something on the order of 6 or 8 turns ought'a do it (there's a 'fudge factor' in that number of a couple of turns).
If done 'close' to correctly, the only thing affected by that choke will be what's 'flowing' on the outside of that coax, not what's on the inside (the only reason why it's worth doing at all).
Chokes are NOT fool proof, they don't work all the time. They do tend to at least help, though.
That ought to get you into the 'ball-park'. Finding the right seat is up to you.
- 'Doc

As far as the GP kit, fugedaboutit! The antenna was designed to be used as is, and doesnt need anything else to do so properly. It is basically a dipole antenna in itself. IMHO, the gp kits were created to get money from suckers who either dont know any better, or have to have every part sold to have a good station.
Keep the money in your pocket.
JM2CW!

PR

Hello and thanks for your replies, i've done a search in the meantime and come up with this site on making a All Band HF Air Core
1:1 Choke Balun

BUILD AN AIR WOUND 1:1 CHOKE BALUN FOR HF - THE UGLY BALUN! i hope you also find it usefull.

As for the ground planes on the imax i'm still not sure on what your saying, but i'll bear it in mind. Has anyone else had any joy with the GPK for the imax and what was the results?

Once again thanks guys..

if you dont add a ground plane kit to a 2000/99 it will use the coax and/or mast as a ground element . here is an excellent thread about wire weasles adventure/results with adding ground elements to his . highly recomended reading to 2000/99 owners IMO .

Recommend Ground Plane Kit For Imax 2000?

if youre gonna upgrade to jays i10k , i wouldnt waste money ungrading an antenna youre not gonna use .

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Minimum coil form diameters (to prevent coax damage):

RG8X/RG58/RG59: 5" minimum

RG8/RG213/LMR400/RG11: 8" minimum

Other types: Diameter at least 20x the cable outside diameter.

Use smaller sizes at your peril, and that of your feedline.

__________________
If you're like everybody else,
you're about average.
73 de K7KBN

not true,
the imax is an endfed 5/8wave, it does need radials a choke and isolating from any conductive mast to ensure best performance,
imho they are sold without radials at less cost to get money from people who do not have the space for radials or people that do not understand/dont want to understand how antennas and feedlines work,
there is plenty of good information in publications and on the www,
sadly there is 100x more misinformation passed around the www

__________________
the blind lead the blind but the enlightened will lead you to the sigma4

Delta this Website link you post tells us to use 20+ feet of RG8U like 213 for 27 mhz, it think. They also describe in their image of such a coil with only 7 turns of coax on the forum. That might require a form 10" in diameter to accomadate that much coax the size of RG8/U or 213.

This is quite the opposite from what ARRL Antenna Handbook suggest 6' feet of RG8/U with 6-8 turns for 21 thru 28 mhz. ARRL also suggest 20'+ feet of RG8/U to be used for 75-80 meters. To be fair though, ARRL notes also that "lengths are not highly critical."

How say you, have you tried the Ugly Balun talked about on that site?

Hello there Marconi, No i have not tried out this choke method yet. I only found it the day i posted it on here and thought you guys might also be interested in reading it.
I think i just might go ahead and buy the i-10k and use a choke when i put it on my tower. The reports look good and the build quality also. I hold a ham licence so i guess i could use it on HF with my ATU, I'm only a 2E1 licence. I've had the I-max 2000 for about 10+ years and fancy a change. Do you think the I-max 2000 with a GPK and a choke would perform as good as the I-10K?
Thanks for your time guys..

Thanks Booty Monster i read that thread, hmm very interesting indeed. I'm very interested in Jays i10k though. What are your thoughts on this antenna compaired to the i-max 2000?
thanks guys..