Talk:J-pole antenna

message: Oh come on.  The reference doesn't check out and why would a country have an official antenna.  Crcwiki (talk) 22:30, 19 November 2015 (UTC)
thread_title: Official antenna of Jamaica?!?

message: I've incorporated many of the comments below and added a great many references I found after extensive research.  There is always room for improvement.  For now the basics of the j-pole antenna are well documented.  Hopefully it will help dispel some of the myths in the j-pole community such as the SlimJim having a gain over the regular J, masts don't conduct current and other fictitious and misleading nonsense.  There are quite a few manufacturers who make these claims leading customers astray.  This fact emphasizes the importance of this article as an educational tool to combat the nonsense and help customers spot and report False_advertising.  Anyone bringing new material to this article needs to have rock-solid reference material to back it up. Crcwiki (talk) 15:18, 2 October 2015 (UTC)
thread_title: Updates by [[User:Crcwiki|Crcwiki]] ([[User talk:Crcwiki|talk]]) 15:18, 2 October 2015 (UTC)

message: Hello fellow Wikipedians,
I have just added archive links to  on J-pole antenna. Please take a moment to review my edit. You may add  after the link to keep me from modifying it, if I keep adding bad data, but formatting bugs should be reported instead. Alternatively, you can add  to keep me off the page altogether, but should be used as a last resort. I made the following changes:
*Attempted to fix sourcing for http://w4rnl.net46.net/jp1.html
*Attempted to fix sourcing for http://w4rnl.net46.net/sj.html
*Attempted to fix sourcing for http://w4rnl.net46.net/jp4.html
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Cheers.—cyberbot IITalk to my owner:Online 02:25, 31 March 2016 (UTC)
thread_title:  External links modified 

message: Thanks to Chetvorno for many very good edits, but I think this one is not helpful.
The statement that "Using low impedance feedline like 50 ohm coaxial cable usually requires removing the short at the bottom of the stub and connecting the feedline at the bottom." is not correct.  Almost all J poles are fed by moving the feed point up from the shorted end till a match is found, even with 50 ohm feed.  It is true that the quarter wave line can be fed directly at the bottom with no short, but this had the mechanical difficultly of supporting the short side (in the case of the "copper cactus" version) and even more serious, the only way to adjust the Z at the bottom is to change the Zo of the quarter wave line, which must be the geometric mean of the feed lines Zo (50 ohms typically) and the Z looking into the half wave section, which will be high.  It is true that the original Zepp, as shown on the patent was fed via a link at the end, without the short.  In those days, 50 ohms was not a standard and the transmitter link output could feed any reasonable low Z, so the exact value didn't matter.  If anyone can find a reference to substantiate the removed statement, I would  like to see it, but I find it very contrary to my own analysis and experience. There are many thousands of 50 ohm fed J poles in use with the short on the bottom, and I have never seen one without it.
As a substitute for the removed statement, we might add that it is possible to feed the J pole directly without the short as long as the Zo of the line is the G.M. of the two matched impedances.  However there is no real advantage in doing so and it is not commonly done. BTW this approach looks very appealing when looking at the J pole on a Smith Chart, but in practice it isn't very useful, in my experience.
JNRSTANLEY (talk) 11:33, 15 May 2021 (UTC)
thread_title:  Feeding without the bottom short 

message: I see some new sentences with no primary references.  This article was previously and painstakingly well referenced.  The new unreferenced sentences have been tagged along with the section they are in.  The new points are valid and I will help seek primary references.  If references are not found in short order, they will be removed.  Let's not let this concise wiki article about the J antenna turn into the travesty that is the article on the the dipole antenna. crcwiki (talk) 04:41, 24 May 2021 (UTC)
thread_title:  Citations needed