I have 25' of 3/8" copper tubing and bad reception. Have had the tubing for several years, it's doing nothing, and I have no other plans for it, and after reading about the outdoor use of vertically mounted dipoles as pretty decent omnis, it occurred to me that I have three hall closets in a row on the other side of the wall behind my audio cabinet, so I should try out the tubing.
I'd also read that thicker copper wire is better for reception than the super-thin wire of the common cheap folded dipoles. Well, tubing is pretty thick, and it is copper. can it be too thick? I don't know, but it is rigid, which is why I have decided to use it.
You see, I live in a 70s ranch-style house on a slab. Hipped roof all way 'round, so even tighter as one nears exterior boundaries up there. I'm unable to climb even one rung of a ladder, much less crawl across ceiling joists, and the blown-in insulation is nasty stuff through which nobody likes to wade and wallow. Too much for Christine, who would also have a difficult time locating wall top plates, much less the right one.
Hiding the antenna in the back of a closet, I figure I can drill a hole just big enough for the tubing through a top plate (2x4 lying flat, you know / more likely through the ceiling itself to make the job even simpler) thereby gaining some height, by having one of the T elements in the attic. Not ideal, but bound to be better than the thin wire dipole I'm using now, taped to the back of a cabinet that is less than 30" high. Nobody has to climb into the attic.
I'm gambling that the top element wont push past any 110 wiring that might inject too much RFI by proximity (inserting from below, blind). Sure, I'd rather have more height, and I'd be willing to purchase a mast if I were able-bodled. Life is all about compromise quite often.
So I'm planning to make each element 30.5" long, so almost 30" will be above ceiling height, in attic, meaning the tip of that one will be a smidgen over 10.5' above ground, near enough, whereas the lower end will just be about 5.5' above ground. Not good, but better than the whole antenna less than 30" above ground. I've made up my mind to try this. My experience with indoor antennas says you don't know what will work in a given location until you try, and this is an easy try.
I have a couple questions.
I've read that the first 20" or so of the 75-ohm RG6 should lead out from the middle of the T at a right angle. Would it be advisable to sweat 90-degree elbows to 20" lengths of the tubing and simply connect the balun to the ends of those, or does that 20" need to be shielded cable? Or just wouldn't make any difference anyway?
Would it make any sense to make the upper element longer than the lower, for more height? Maybe make the overall length come out the same? I suspect that might mess up frequency matching, as dipoles are always the same length each element, as far as I've ever seen.
The cable will run straight through the wall, and I'll use appropriate switch plates to hide the ugly holes, so there will be no other breaks/connections between the balun and the tuner back panel antenna input.
The tuner is the little Sony HD. My home is brick, reception is lousy, and the Sony performs better than any other tuner I've had, or have, in this house (two Kenwood KT 615s, NAD 4130, Emotiva PT-100, Pro-Ject Box tuner, and a few others). I'm just trying to receive locals better. Only about five or six stations come in without noise now, but there are others that are trying. I'm not expecting dx miracles, just want the locals clean, and the Sony is a good bet for that, imo.
Any comments, suggestions and answers appreciated.