home brew j pole in th attic... copper pipe or ladder line?

[mparker]

i am going to put a home brew j pole in the attic to TX on 2m/70cm (but mostly 2m) but i cant decide whether to "build" it with copper pipe or take the cheap way out and use ladder line...

and also how do i ground it in the attic?

 

[timkilbride]

i am going to put a home brew j pole in the attic to TX on 2m/70cm (but mostly 2m) but i cant decide whether to "build" it with copper pipe or take the cheap way out and use ladder line...

and also how do i ground it in the attic?

I have built some 1/2 wave(no ground plane needed) antennas out of 300ohm twin lead tv antenna stuff. You can buy it at RS. The antenna is a folded 1/2 dipole, stand about 60" tall on 2M. Not sure how well it would do on 440.

Tim K.

 

[mparker]

i was looking at those ladder line antennas too... it would defiantly be the easiest to build and cheapest too....

but i figure if its going into the attic covered from the elements, i might splurge and take the time to build/learn about antennas...

 

[N0IU]

Since it will be indoors, the ladder line version will probably do just fine. If you are going to put one outdoors one day, the copper pipe version will work much better. No need to ground it in the attic.

If you haven't done it before, I would search for "how to sweat copper pipe" and read up on this. Its not hard, but it takes some practice. Unlike doing the actual plumbing in your house, it doesn't have to be perfectly water tight for an antenna!

 

[mparker]

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You make a good point.... ladder line it is then...

I've read you can get some killer deals on the ladder line at radio shack..

I might throw up a diy SW too whille I am in the attic.... I would think I could use the same ladder line...

What coax do I feed to the 2m jpole? It will be about a 75-100' run.

 

[timkilbride]

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You make a good point.... ladder line it is then...

I've read you can get some killer deals on the ladder line at radio shack..

I might throw up a diy SW too whille I am in the attic.... I would think I could use the same ladder line...

What coax do I feed to the 2m jpole? It will be about a 75-100' run.

LMR400 would be ideal.

 

[N_Jay]

Ladder line will be end up being much narrower bandwidth.

Why a J-Pole?

Just make a dipole or ground plane.

 

[timkilbride]

Ladder line will be end up being much narrower bandwidth.

Why a J-Pole?

Just make a dipole or ground plane.

Narrow bandwidth wouldn't be all that bad if its just for 2M. Would probably help on intermod if he is located in a city, ect.. . .

 

[jsm190]

I have one made out of 1/2" pipe that has been in service 10+ years. It is outside on only a 10' mast and I can work repeaters in 4 counties. I have never tx on a twinlead j-pole but I have a 300 ohm one on my scanner and the pipe one receives much better. Going to make another for the scanner.