I've been cleaning around the shack tonight and monitoring across 75 phone and also a little 2 meter chatter on Louisville repeaters.
There's a fellow whose call I'll avoid mentioning because he seems to wander from frequency to frequency across the phone portion of 75 meters. This fellow has taken the idea of adjustable antenna elements (as implemented by SteppIR) and is using it with an inverted vee dipole.
A motor and two spools of stainless steel tape reside in a box that you must mount at the apex of your inverted vee. Two nylon lines come down from the box, and the conducting legs of the dipole slide up and down these lines when its adjusted. It's not automatic, you have to tune the antenna for your frequency for lowest SWR.
I have heard this ham roam around the 75 meter band discussing his discovery for literally years. He makes all the major hamfests, and he's as enthusiastic as any inventor who believes in his product. I've heard him stop and join roundtables all over 75, and he'll go into detail about his invention, its benefits, etc.
This “system” has been in development for at least two years and I'm sure more than that. According to the QSO he was in tonight, he still doesn't have a marketable product. He said if someone really wants one, the cost would be $2,400. He's still working on prototypes.
I head him nearly two years ago tell some fellows that he was trying to sell his product to a manufacturer but had no takers then, and apparently none since.
The question he needs to answer is simple: Does anyone really want to pay 2 grand for an adjustable dipole? Presumably none of the manufacturers he's shopped it around to believe they will.
He said he may try to work on a $600 version that might actually sell. I wonder if you took my center-fed Zepp and compared it to his antenna — all other variables being equal — if you would notice a difference between the two. On my Zepp, on 40 and higher bands, there's at least some amount of gain over a resonant dipole (though the pattern may not be as nice as a resonant antenna).
He discusses his antenna as though it was the answer to every ham's antenna problem. He reminds me a little of Ross Perot when he was running for president. “See, you just gotta have one of these, you can't beat a resonant antenna — just look at my chart …”
And I guess his antenna might be “all that” (as my daughter would say). Instead of my simple wire antenna I would have to hang a big box in the tree and run DC power to it. Hmmm.
OK, next, let's breakdown costs vs. benefit. Ross, the charts, please.
Zepp cost: $15 worth of copper wire, $20 worth of feedline. Total $35.
Fancy-pants adjustable dipole: $2,400, feedline not included. Total $2,500.
Will the adjustable dipole give me $2,465 more enjoyment than the Zepp? No. In fact, my wife would probably faint dead away if I told her I had a $2,400 box that I had to hang from our tree.
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This evening while tuning 75 meters I also ran across a CW bug I had put away and essentially forgotten. It's a Telegraph Apparatus Co. (TAC) bug from about 1945. The company was a joint venture between the infamous T.R. McElroy (of Mac Key fame) and Bill Halligan of Hallicrafters. The company was headquartered in Chicago. (The one in the photo isn't the one I bought, but mine is identical).
You don't see TAC bugs sell often, but they're fairly plentiful. I have three deluxe models with chrome plated bases, one that's only fair, the other two very nice. Many TAC bugs had painted bases. Many were built for the military from what I've read. I picked up a TAC bug a couple of months back that was in excellent shape. The chrome is very good and the base is grey crackle finish. The only flaw with the key was the fact it had been dropped in the past, and the thumb piece (paddle) was broken off and the keying lever was slightly bent.
I figured that coming up with a replacement paddle for a TAC bug is a tall order. I have some black acrylic, and I figured I would simply cut one for it. As it turned out, that was not necessary. The spacing on the holes looked similar between the TAC and a Vibroplex bug, so I tried a Vibroplex paddle. The rear mounting hole is larger and countersunk into the paddle material, but the spacing and shape was just perfect. Some work with an Xacto knife was all it took to put the TAC bug back on the air with a new paddle.The finger knob (round knob) was still the original one, and its amazingly like the one found on Vibroplex keys of the era. In fact, they look identical.
And speaking of the TAC bug, I disassembled one of mine about a year ago to take its measurements. The TAC bug, of all the keys I own, was designed to be inexpensive to build. The base is cut steel, not cast; all the fastener sizes are the same throughout the key; the key uses the same size posts and screws throughout. This key was likely cheaper to build than even the Vibroplex Champion. If you mass produced the parts you could quickly build a zillion.
I had plans last year to enter a CW key of my own design into the SPAR key contest, which was last October. My plan was to take the pivot frame design and modify for my key. I was going to borrow some construction elements from some other keys too. A machine shop would have been helpful. I completed a set of drawings for the key but did not build it. I don't know that I ever will, but it sure is fun to design and think: What if?
That's it for this installment …. 73
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