Vanguard Labs

Dept. H

196.23 Jamaica Ave. Hollts, N.Y. 11423

Charles Leedhom WA2TDH

Drawings by Woyno Piorcc K3SUK

I he Zero Meter Band

Back in the October 1964 issue of 73 Magazine, you may have noticed a small ad inserted on page 86? announcing the attempted unloading of mountainside premises somewhere in New Hampshire, complete with a considerable selection of antennas, Within that tempting array, your eye may just have skipped over the fact that it included, and [ quote, "Hy-Gain Tri-Bander for 0-15-10M." Even if you did happen to notice the peculiar specs on that antenna, almost certainly your eye slid over it, thinking it no more than another of the many typographic atrocities perpetrated by the pereniallv sloshed typesetters up there on that N.H. hillock, what with it being cider season and all. Only a few insiders were aware of the fact that it was quiet notification by the editor that the old Zero Meter Band was open again.

It was many years since Id been on Zero the last time, with my original call, and the idea that the band was opening up again naturally brought back many nostalgic memories of old-time operating before the govern-

The Zero Meter bond rig

ment not only closed it down earl) in 1942, but confiscated every bit of equipment known to be in private hands.

1 never did hear after the war that Zero was open again. The regulations said anything above 40K megs was okay, but 1 was sure that didn't mean Zero. Mainly because I'd heard stories during the war about the experimental work the government was doing with Zero Meter Radar, and I figured that in the slather of stuff that was ultra top secret afterward they'd included Zero. 1 didn't want to ask, you know how it is, not making waves and all that Nobody wants any 3 a.m. visits from conservatively dressed types wearing snap-brim hats wanting to know just how much I knew about Zero Meters, and where Id learned it, and exactly what was it 1 talked about to the foreigners on mv private radio station, That sort of thing.

Now 1 figure they must have given up the experimental work because of troubles like the ones 1 did hear about There was a fairly well substantiated story that they did work out the antenna problems and get just one Zero Meter radar station working somewhere in England. Up to then they'd been working with stuff as long as ten meters, and were slowly finding out that the shorter the wave, the greater the definition. Naturally, with the zero wavelength on Zero, the definition would have to be pretty good. According to the story, when they fired up the rig and pointed it at a wave of bombers coming in, it was so good they could read the dogtags on the German aircrews. Used to scare the hell out of the Luftwaffe high command by broadcasting back to Germany not only the names, ranks and serial numbers of everybody on a mission, but even their blood types.

Either that last touch finally tipped off German intelligence, or their agents in Eng-

Zero Meter radar was set up in England.

land got wind of what the installation could do, and they pulled a real cutie. Late in '43, I think it was, they sent over a special flight on a bombing run. Had to search all through the Luftwaffe and Wehrmacht for them, I think, but every man Jack of the two thousand crewmen on that flight was named Schultz, rank Feklwebel, blood type AB. Naturally when that list went up to 02 from the Zero Meter Radar crew, some brass-brain upstairs decided the thing must be on the fritz and ordered the techs to take apart the Blue Box. They protested, of course, but orders are orders, so they cut it open with a weeding torch. As any of the old civilian Zero Meter ops could have told them, that was the end of that. Whatever was inside was melted into a few droplets of slag by the time they could make a big enough hole to shine a light in, and that was the end of Zero Meter Radar. At least that's the story I got from guys who were near the project.

hat was one of the most frustrating things about Zero—those Blue Boxes. You read a lot these days about how sad it is that everybody is an appliance operator and that there's hardly any homebrew in g any more like in the old days. There wasn't any homebrew equipment on Zero at all. Everybody I ever contacted on the band was working with the same old Blue Box. As far as anybody knew, they were all World War I surplus rigs; at least we all found ours the same way, knocking around in the |unk piles at the backs of the WWI surplus stores. They never did get in the catalogs, because the store operators fortunately didn't know what they were.

It wasn't surprising either, because a Blue Box didn't look like much, it was a small box about six by six by ten, with a dull blue-black crackle finish. There was only one knob on the front, a jack for a key, another for phones, and an antenna terminal on the back. No label no brand name, nothing, ust a plain Blue Box, except for the peculiar business about there being no sheet metal screws or rivets, or any way at all to open it up.

Some of us tried, of course. Any ham would be curious about the circuit and components that could handle that kind of frequency. But drill bits got blunt and hacksaws didn't seem to have any el Feet, so we gave up on that angle and just operated. We all heard about the guy who couldn't take not knowing and went at his with the blowtorch. He never showed up on the band again, fust like with the radar unit, when he got it open he found everything inside melted down. One of us— I don't remember now exactly who—got a postcard telling what happened, and about how-he was looking all over the country for another Box, but he apparently never did find

one.

We had to admit that the theory of it was beyond us, which is why we never got very far in homebrewing, or even in drawing up tentative circuits. After all, how do you design a tank circuit that is resonant at infinity megacycles? rhat, unfortunately, is the way it goes on Zero. If the wavelength is zero, you can t fight the fact that the frequency has got to be infinite. Some of us had a few bright ideas about designs, but search as we would through the old catalogs, we never could find specs for components that would come close to what wed need. Maybe soon, with some of the new microminiature stuff that's coming out, but back then there wasn't

Of course, it was hard to open up the Zero Meter rig.

a tube on the market that could handle infinite frequency. At least, not with enough gain to make it worthwhile wiring into a breadboard circuit.

The frequency, of course, was why everything on the band was C\V, If you think about it a little, you'll see that modulating a wave means you are adding to it and subtracting from it. And if you've had the math, you know that no matter what you add to or subtract from an infinite frequency, you still have the same frequency at the output. Maybe phase or pulse modulation might be the answer, but we didn't know enough about that sort of thing then.

That was the reason the old Blue Box was so simple, too. If you re rock-bound on a single frequency, you don't have to worry about tuning and loading and such. There was only that one knob, which was on-oif and receive volume. No \ :0 or frequency read-out, of course, because you can't QSY on Zero, for the same reasons you can't modulate it. And when I say rock-bound, incidentally; I say it because I imagine that was the way it was done in whatever circuit was inside the Box. We did a lot of speculation about it on the band in the old days, laboriously tapping nut our theories to each other. About the only thing we came up with was the fact that it had to be that way—seeing as a crystal gets higher in frequency as you grind it down, then if you keep grinding and get it down to zero thickness, then it has to oscillate at an infinite frequency. Makes sense*

I tried once, figuring if I was ever going to build up a circuit on my own I might as well start with the crystal. I ground and ground away, and after ruining a lot of stock finally managed to get one down to zero, but

Building a Zero Meter beam.

as soon as I tried to pick it up the damned thing shattered. That was the last time I tried working on zero-thickness crystals. I'd worked so hard mastering the technique of getting them down to zero thickness—and that's precision work, believe me, with no tolerances at all—that 1 didn'1 want to spend another year or so figuring out how to handle anything that thin without breaking it.

My crystal fiasco naturally brings to mind the story of poor Joe, who was experimenting with the antenna end of tilings. That was one of the real pleasures of working on Zero, the fact that you could work up a really fancy antenna and not have to worn about space fir big hunks of metal hanging up there in the sky to worry ifie neighbors. On Zero, you can obviously have all the elements you want, on a zero length boom, and with zero length elements. You have to be pretty careful about spacing, though. If you re off by even the littlest bit your directors start acting like re-llectors, and you end up with a pretty confusing polar plot.

1 never bothered with more than 42 elements on my own beam, but Joe decided he was going to go for brqke and really put out the rockciusher signal of the band. You know how some guys are ii they don't get forty-over reports every transmission, ioe d worked on his beam for over 12 years and managed to fit something over four thousand elements onto the boom— he'd lost track once, and wasn't sure exactly how many he had, because of the difficulty of counting zero-length elements on a zero-length boom with zero spacing--but he did know he'd put on more than four thousand. Then one dav fie had the beam r taken down and in his shack to add still some more elements, and while he was out getting some more zero-diameter aluminum element stock bis wife came into the shack and opened the window, I need say no more tlian that there was a strong breeze that day, and poor Joe never found his beam again.

At the trial, Joe kept sobbing so piteouslv and mumbling over and over, "Cone, gone, gone'5 that the jury couldn't believe anybody that grief-stricken could possibly be responsible for his wife's mysterious disappearance. It took the spirit out of Joe, though, all those years of work lost, and the last I heard from him he was working low frequency, '¡own on the 20-Micron band,

I think Wayne was a little reluctant to let the news about Zero get around too much, which is why he gave us OOT Zero ops the word in such a coded fashion. But i ve managed to convince him that somebody has to get out a warning about Zero antennas just in case one of you stumbles across a Blue liox up in the attic, or finds one in a surplus store. We're both convinced that there aren't any left, but still, just in case.

The warning is this: whatever you do. never use a long-wire antenna on Zero. All of us on the band back then knew enough about antenna theory to know what was likely to happen if we put even a one-inch wire on that antenna terminal and operated it as a wire antenna instead of running a feed-line to a properly designed, resonant Zero Meter antenna. If you look at the charts in the manuals, voull see why yourself. The gain of a long-wire goes straight up as the antenna lengthens in terms of wavelengths, and there doesn't seem to be any fall-off.

Consider the wavelength of Zero, and you see right away that any length of wire at all contains an infinite number of wavelengths; That means, of course, infinite gain in the antenna, which means that the minute you hit the key you'd put out an infinitely strong signal It would slop over onto every other frequency in the spectrum, still with infinite strength, and blow out the front end of every other receiver in the world. And eventually sm in the Universe. It would only be a split microsecond pulse, but enough. Or maybe that strong a signal would instantaneously melt your longwire, and thus no signal would grt out at alL I'm not really that strong on theory, but thats the way we used to figure it—that it would last long enough to get that infinite-gain signal out—and so we never dared try to see if it was right. If you should find a Blue Box, take heed!

The reason I'm back on Zero is that when the big confiscation came, i turned in the Box 1 was operating with, and completely forgot that \\\ picked up a spare, and that

Joe kept sobbing pitifully at his triaL

it was lying behind a lot of other old radio junk in the cellar* But when 1 read Wayne's ad I suddenly remembered it, after all these years, and went down and found it. I dusted it off, plugged it in, and put out a tentative CQ. Much to my surprise there were some answers, so pretty much the same must have happened to some other guys.

I recognized a few of the calls, and it was a real pleasure to meet old friends on the band. There were a few pretty strange prefixes coining in, though, and when I asked one of my contacts about his exact QTH—but that's another storv.

Dig into the backs of those \\ \W surplus stores. There may still be a few of them around. Maybe you'll be luek> enough to find a Bine Box. fust be extra careful about not putting on a long-wire, and 111 see you on Zero.

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  • Jess Lewis KR4OJ
    One of the best light humor articles that I've ever read, about Ham Radio. I had read it back in '66, when I was in the NAVY & a 73 subscriber. But, although I never forgot the article, I mis-placed my copy, during my many moves around the country. I was pleasantly surprised to still find it on the web. Thanks for the fun & memories Chuck.
    9 years ago

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