Following my experience, nothing you can notice in real conditions.
The advantage of the slim-jim is that with some materials it is easier to build.
Le 23 nov. 2012 à 11:47, Sajeesh Pilakkat a écrit :
Any difference in propagation angle - j-pole vs slim jim?
-vu3pszSent from Yahoo! Mail on Android
From: Raj <vu2zap@gmail.com>;
To: <HamBrewers@yahoogroups.com>;
Subject: Re: [HamBrewers] j-pole or dipole
Sent: Fri, Nov 23, 2012 4:21:18 AM
Hi Yan,
I built mine from 1/4" aluminium rods (easy to bend). The matching section was a slider mechanism that was made with a potentiometer locking collet nut like this. They were mounted on a bakelite strip along with the coax connector So-239. Turned up neat and easy to slide up down the matching section.
<4c9643.jpg>
Pic from here http://www.sdp-si.com/web/html/shaftacc.htm
At 23-11-2012, you wrote:
Hi Raj,
I agree, on VHF and higher the J-Pole rules.
You have to be a really rich plumber to build a copper J-Pole on 80m!!!
On HF, I build several ones with coax and twin-lead for 20m but it was rather deceptive.
Not bad, but no much advantages compared to a simple dipole and the disadvantage of 1/4 wave longer.
On VHF I also build a 2x5/8 colinear antenna based on a J-Pole. Easy to build and it has gain.
http://xv4y.radioclub.asia/xv4tuj-station-radioamateur-en-ok20ua/colineaire-j-pole-2x58-sur-144mhz/
http://xv4y.radioclub.asia/wp-content/uploads/2011/11/A1_Schema-5_8e.pdf
It was inspired by a Swedish or Danish article, but I lost the link...
73,
Yan.
---
Yannick DEVOS - XV4Y
http://xv4y.radioclub.asia/
http://varc.radioclub.asia/
Le 23 nov. 2012 à 10:08, Raj a écrit :
> I presume it is for VHF then I would chose a J pole.
>
> Raj, vu2zap
>
> At 23-11-2012, you wrote:
>>
>>
>> im very new & i want to build my own antenna
>> & used to be a plumber so have lots of copper tube
>> should i build a di pole or a j-pole ?
>> Many thanks
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
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