It looks like Bob Hejl W2IK is resurrecting his web site at w2ik.com after the AOL shutdown the Hometown hosting site. Later, I'll fix up the links once they are active again.
Most of the links included below connect you to other sites; if you have difficulty accessing the information from these sites, you might try the Internet Archive or Wayback Machine. Lacking success there, let me know--I might be able to help.
Recently, I have encountered several resources new to me that helped me understand J-Poles and the reasons for the recommendations in these construction articles. Thus the new revision to this page.
Miahael Toia K3MT has written several books on antenna theory. These books, among other topics, are described on his website. The Antenna Topics book has a chapter on J-Poles & Zepps that provide flesh to the assertion that "any antenna can be tuned to 50 ohms with two transmission lines". I've found K3MT's books to be both fascinating and quite educational.
Gary O'Neil N3GO has an article From a J to a Zepp hosted on the website of Rick Huebner W0RCY. This is a fascinating investigation of the fundementals of the J-Pole and contains an explaination of the whys and wherefores J-Pole tuning--this explanation removed, for me, the mystery of tuning these antennea.
So, I'll still use the construction techniques below, but do so with the improved understanding of why they work from the resources above.
I was asked about my J-Poles for 2m use. Here is some of the 2m J-Pole information I used when constructing mine.
The J-Pole plans I actually used (and specific tuning guidelines) are from Bob Hejl W2IK.
I added a "cable shield" (actually 1/2 of a coupler above the coax exit point) so
that when nesting the PCV into the telescoping pole, the coax would not
be cut by the sharp edges of the pole.
Self Supporting J Pole
Bob Hejl W2IK has some other J-Pole variations I'm considering too, starting with
this one.
Emergency Deployable VHF Antenna, part 1
part 2
part 3
This is a good article by Mike Walkington VK1KCK, on the J-Pole (I've seen portions of this scattered around
the web, but this seems to be the original and it includes the often missing diagrams)
J-Pole Antennas
Don't forget that L.B. Cebik W4RNL wrote on the J-Pole. This site requires free registration, but
it is worth reading.
Some J-Poles That I Have Known, part 1
part 2
part 3
part 4
This article by Jamie WB4YDL is where I first encountered an actual guide to the tuning process
that emphasized the relationship of trimming the long & short end. It was
probably out there in all the material available, but I just never noticed. However, I like Hejl's cutting
method better as it seems more precise and it is harder to cut too much off.
A Simple VHF / UHF J-Pole Antenna
And finally, here is an important tidbit from Jim N1QNK that seems obvious, but I do not recall
as having encountered on other J-Pole discussions--the importance of feedline
length to the overall tuning/performance of the J-Pole.
Portable 'J' Pole Antenna For 2 Meters
So, in brief, I'll be using W2IK's plans for future VHF/UHF J-Poles while keeping in mind the importance of trimming both ends for tuning, as well as N1QNK's odd-integer multiple of quarter wavelengths feedline length feedline recommendation.