I had the same concern about the gap in between the rods no matter how you applied it, and while not a real circuit in conductive contact rather than having a break the virtual rod with any insulating material, I figured the heat shrink would be enough.
My experience was that I didn't have to waste time (in retrospect) with the futzy and potentially ruining a set by having the glue leak down and adhere to whatever it was holding the rods in alignment, such as a piece of angle aluminum, etc.
The shrink wrap sizes given were perfect, and using a true heat shrink gun (cheap as anything I've gotten lately, from Harbour Freight) made the shrinking fast, fun and nearly foolproof, vs. trying to use my wife's hair drier.
The worst part of winding the rods was the initial piece of wire that had to stick out a foot or two and go round and round while I wound it, but the second one went better when I realized I could roll the extended lead up in a circle and gently tape it to the end of the rod after I got the first inch or two wound on. And winding for a bit and applying a little bit of Scotch 3M electrical tape to keep it from unwinding if I had to take a break or maybe a sip of something, was helpful.
I used the smaller gauge diameter enamel, too. One thing that some of the initial stuff from the development team was cautioning that proper spacing between the winds was necessary, even implying that a dummy cord or something to specifically separate the winds a little bit was needed. I don't see anyone doing home brew doing anything except nestling each rotation up next to the one that was just laid down, forming a relatively solid wind, almost like a hose on a reel or line on a fishing reel.
I don't have a rod from the kit so I can't comment as to how the ones that are sold with the kit are rolled.
Has anyone taken a look at what Egon, et.al. are sending out? Are the winds next to one another, or is there some spacing material wound along with it to separate them a bit?
Nonetheless, the proof is in the pudding, and these home built ones, no matter what size wire used, and whether or not glued or just heat shrunk, seem to be spectacular.
Considering the rods are first shrunk, then wound which actually does give a teeny bit of stiffness in its own right, then again heat shrunk, then placed in some sort of support like cotton batting or live rubber or the stuff I used, low density foam rubber strip used as a window door sealer that is adhesive on one side, and then stuffed in PVC means that they'll withstand a 12.7 on the Richter scale and still stretch and yawn and shake it off.
I think the glue is not needed.
I think there are many factors on the size of enamel wire used, including more wraps means more magnetic line crossings as the wave moves by, there are resistance changes, there is the impedance which affects the filter resonance and Q, etc. which I'm sure technically makes a difference. But again, if the engine starts and runs, who cares if it is 87 octane or 91?
On the other hand, I'm sure if NASA was doing it, they'd test glues vs. no glue, and length of rod and size of wire and spacing of wraps and so on, and find some differences that might make a difference if the probe were going to the heliosphere or a person's life depended upon it. But if it works and is close to optimal, it probably isn't worth anyone's time doing those experiments.
I have an interest in antennas, so if there are those who know the answers to some of the questions being raised, I'd love to hear the comments. I love the impetus to learn and look stuff up that this movement has generated.
Dale
