Gary's J-Pole

[BOOTY MONSTER]

herd about this antenna on another forum . dude was talking pretty good about it s said it uses "all t-6 aircraft alluminum construction throuout" . anyone here know anything about it ? 27 feet tall so a 3/4 wave ?

 

[W5LZ]

If it's a 'J'-pole, then it's a 1/2 wave antenna, not 3/4 wave. The length of the bottom section from the feed point on the long part to the other end of that '"U" isn't counted as part of the radiating element. It's the 'other half' of the antenna, the impedance matching part of the thing. Like radials, sort of, just a different shape. They do work!
- 'Doc

 

[bob85]

its a regular jpole booty, those boys are crazy and just refuse to learn, they see gary as some which doctor who discovered how to makee a regular jpole make 9db gain,
their method of testing is totally flawed, he even posted a link to the site where gary got the jpole info from and claimed that was proof it can be done,
i pointed out that the article says you need colinear stacked sections to get close to 9db but he cant even read a simple article whuich he posted as proof,

it is a regular jpole 1/2wave over 1/4wave feed section, just like a slimjim some folk think they have huge gain over other antennas, they dont but they can have a lower angle of radiation than an endfed or groundplane that is not installed correctly, meaning one that is electrically connected to a conductive mast or one with a ground wire running down the pole or unchoked coax feeding it for those nice common mode currents to flow on and ruin your antennas pattern,

99% of people using groundplanes and endfeds like imax are not getting even close to the pattern they should be getting because of all the mis info on how to install and ground antennas floating around on the www,

when compared to such a poorly installed antenna i dont dispute they are seeing what they believe to be 9db gain, they are not alone,
i dont doubt it could beat a 10k clamped to a 25ft conductive mast but 9db gain over a correctly installed groundplane, not while ever i have a hole in my arse.

 

[Robb]

Some HAM clubs have initiated members by helping them build their own j-pole - with copper 3/4" tubing. Cost; about $15!! Nicknamed "the copper cactus" - because one of the tuning members comes out at about mid point and makes a u-turn for a specified distance - or 'J' if you like. The copper ones are the way to go; but you had better take time and patience to tune it right. When finished, one has to give it a coat of klear-kote to keep the copper from corrosion. Then, you will need to keep any of the SO-239 parts from getting bent or twisted - so you will need to wire-tie it carefully on the PVC mounting pipe carefully.

9db gain? Some say more; but I suppose it depends on who is measuring it and how well they compute the result. If nothing else, I think that it is important to be able just to make one and be successful at it. So that if necessary one may have to build one if your $400 Yagi should fail due to some major catastrophic event - hurricane - whatever. If there is a value in it - I think that is what it is - IMHO...

It's made for 2m; so it is limited unless you have an antenna tuner.

 

[BOOTY MONSTER]

thanks guys .

 

[DIRTYWHITEBOY]

herd about this antenna on another forum . dude was talking pretty good about it s said it uses "all t-6 aircraft alluminum construction throuout" . anyone here know anything about it ? 27 feet tall so a 3/4 wave ?

These guys are idiots booty,over 9db gain from that pos.of course they could have been comparing to a coathanger and the 16 db gain beam they talk about in their forum i think is a result of smoking something.this jpole is cheaper and has better performance than the i-10k according to them,maybe jay can join the forum and learn something.