RF Choke on Imax 2000

[fcunderwood]

What id like to know is #1.What kinda amp are you using for 1200 Watts on 11meters and 2.How the hell you get a Solarcom I-Max 2000 mounted to the tree top.

[tifoercito]

todavia no lo veo pero ya casii

[pyrofful]

Did you first try the antenna with out the choke? Does the choke help a lot with the static?

[fnordist]

Get two Imax 2000 remove the Coils put the Antennas together vertically (like a Extended Double Zepp)

Feed it with a 300Ohm Ladder line. (lenght could be calculated using EZNEC)

so you get an aprox 10 dbi gain with an 15 degree takeoff angle.

use a wooden mast or fiberglass and install the thing aprox 22m over Ground

You can use 0.64 Wavelenghts copper rods instead of Imax 2000 antennas

if you want more use 4 of those things cophase it so you get 16dbi gain (12w in 450w EIRP out)

[kinnco]

where was your ground?

[battlestarone]

notice you dobt have the pl259 taped over all the way down to the coax,if water gets into your coax you going to have problems,you only need a small amount in there for swr to go out the windo and rf to start coming down the coax shield,if coax shows signs of water damage bin it and get good grade new cable and new plugs ...the only real way to check swr on an antenna is at the antenna endmnot practical so you have to use odd multibles of a half wave i think or something like that,check the net.

[1112223333111]

@battlestarone ya I find if I leave it like this, it drains easier.

If I tape it, it retains water.

Look at 1:14 I gooped it up good BUT I blocked the drain holes at the bottom of the Imax.

I climbed back up and took most of it off.

I think that belden batch thaty sucked up water scared everyone.

This coax I use is 213 with a super tight braid and jacket.

Plus once I put 1000W though it, she's dry.

[Rennovahtio]

you might see improved performance if you add the choke in about 5/8 wave length down the coax so it has a counterpoise. mine always worked better when i added guide wires to the fiberglass masting. they were about 20 to 25 feet long

[Marconi390]

When you add a choke like you did, which adds length to the feed line, you may see the center frequency change by as much as 20-23 channels up or down.

There is also a small weep hole in th bottom near the feed point that allows water to drain out of the matching area and you may have covered this hole up. It may take some time, but you are likely to get water in your feed line.

The choke looks to be to big. At 11 meters you only need 5-6 x 4" loops of RG8u.

[1112223333111]

@Marconi390 really?

under the antenna?

awe crap......

[1112223333111]

@Marconi390 thanks for the heads up.

I think I found my problem lately with the match going up after a rain...1200W does boil it off eventually, but I will have to shuck the tree and get that sealer goop off there.....@$@^% saakes

[urbex2007]

@Marconi390 if the feeder length makes a difference to the swr then the aerial is broken! stick the choke before your house, it is no use miles away in a tree!

use self amalgamating tape to seal everything.

[sparks146574]

nothen like alittle tree climbin :)

[10SF265]

YOU RE CRAZY MAN !!!

[hmf350hondakid4ever]

y do u need a rf choke how tall is your antenna

[urbex2007]

@hmf350hondakid4ever he doesn't need it, he is a bit confused about what they are for and where to put them. It is serving no purpose on that installation.

[mitteey]

where u get cb radio accesories from?