Tuesday, December 27, 2011

Apprenticeship to a Radioman

This Christmas, I received a unique present. I suspect I am perhaps the only person in the continental United States who got for Christmas a gift-wrapped Supreme Model 333 Deluxe Radio Analyzer. It’s in a polished wooden box with copper hinges, about the size of an old typewriter case. You open it up to find an esthetically pleasing control panel with black enamelling and copper lettering and decorations. In the top center of the panel is a Weston-style needle-and-dial meter in the classic “fan” shape: not rectangular, but curved at the top like a fan. And symmetrically arrayed on either side are control knobs and jacks and sockets for four-, five-, six-, and seven-pin vacuum tubes.

Because there were no eight-pin (octal) sockets on the panel, I said that the thing had to have been made prior to about 1938, which was when octal tubes started to become popular. My brother-in-law told the story of how he’d been walking down the street in New Orleans and spotted this thing in an antique store window. When he said he had to go inside and his wife asked him why, he replied, “I’ve just seen David’s Christmas present.”

Nowadays you can find a website for almost any piece of obscure and obsolete piece of test equipment. It took me about fifteen seconds to find www.stevenjohnson.com, which is operated by a collector of Supreme equipment of all kinds. Supreme was unusual in that it was located far away from the radio-company concentrations of New York, Chicago, and Los Angeles—in Greenwood, Mississippi, of all places. But for a time in the late 1920s and 1930s, it was a major player in the small field of suppliers of test equipment to “radiomen” as they were known: the entrepreneurs who entered the booming field of radio by opening repair shops in hundreds of small towns and cities before and during the Great Depression.

Mr. Johnson’s website provided me with both a schematic diagram and a manual for my prize. The manual appeared to be a hand-typed original, perhaps reproduced by mimeographing. Possibly it was a printer’s manuscript from the company files. At any rate, reading the schematic and the elaborately-worded manual told me what I wanted to know: what was this thing used for, and how did a radio repairman use it?

The Analyzer was what the Supreme Company termed a “free point tester.” It is likely that many radiomen made house calls, especially when you consider the size of the larger floor-model radio cabinets of the 1920s and 1930s. The small table-model sets such as the “All -American Five” (a five-tube transformerless model popular during World War II) did not come into favor until after about 1935, when economic pressures on manufacturers forced them to standardize designs and tube complements. So the problem the early radioman faced was how to investigate voltages and currents in the tubes of one of those large floor-model sets in the customer’s home, without turning the living room into a radio lab by pulling the chassis out of the cabinet and upending a live working radio on the dining-room table. (I’ve tried this at home and it did not meet with a lot of favor.)

The answer Supreme (and several other test equipment firms) came up with was the following. You chose a tube in the radio to analyze, pulled it out of its socket in the radio chassis, and inserted it in the appropriate socket in the Analyzer. Then you selected the proper adapter cable, plugged one end into the Analyzer, and plugged the other end into the socket of the tube you had removed. In this way, you were able to check all the voltages and currents for that tube with special jacks and pin plugs provided in the Analyzer, using that fan-shaped meter to read DC and AC voltages and DC currents. This relieved you of the need to pull the chassis and go poking around underneath the sockets in the radio itself.

Sadly, my Analyzer is missing the adapter cords. But I don’t do a lot of fixing of 1930s radios these days anyway, though I did in the past. In fact, I learned a few things about the lost art of fixing tube radios at the feet of a genuine radioman: Jewell Howard Dowell.


As well as I can recall, the year was 1964, or possibly 1965. I was about ten, at any rate, and was wildly ambitious to learn and do everything I could about electronics. Around that time, my particular obsession was oscilloscopes.

It is hard to explain the position that the oscilloscope occupied in the public mind in the 1950s and 1960s. It was a thing with widespread symbolic significance, and not merely some obscure instrument known only to electrical engineers and technicians. Comedian Ernie Kovacs, of all people, had popularized an oscilloscope trace by including it in his televised comedy routines. The TV show “The Outer Limits” had scared the daylights out of me numerous times, and they always began the show with a closeup shot of a scope screen displaying a dot which widened into a horizontal line and then a vertical one as a sententious offscreen voice intoned, “We control the horizontal. We control the vertical.” And at the Fort Worth Zoo’s aquarium, I had seen an oscilloscope in person, so to speak. Built into the wall above the tank containing an electric eel was an old scope connected to electrodes in the tank. Whenever the keepers would put on an electric-eel display, they would rouse the creature from its normal torpor by poking it with a stick, and it would oblige by putting out several-hundred-volt pulses that were enough to make the green line on the scope screen twitch and wiggle. If the fish really got annoyed, it gave enough of a jolt to light up the neon-sign display above the tank that read “Electric Eel.”

From this experience I had concluded, incorrectly, that electrons were green, because I knew electrons made the line on the scope screen, and the line was green. I thereupon decided that my favorite color was green, and it has been so ever since. Not only was my favorite color green, my favorite ambition of all time was now to possess an oscilloscope of my very own. This presented difficulties.

From the Eico catalog I had sent off for with a coupon cut out of Popular Electronics magazine, I knew that new oscilloscopes were out of my reach financially. Why, a good one for TV repair use might cost as much as a hundred dollars or more. It might as well have been a million, because the balance in my little savings bank I kept in my bedroom rarely rose above seven dollars, and I’d felt rich then. But not now.

At this juncture, there entered a kind soul whose sympathy for my plight I fully appreciated only years later. Buck Sloan was a neighbor of ours who lived behind a high fence in a tumbledown old house cluttered with woodworking machinery, old radios, and even the model of an invention he had actually patented to do something or other at his job at the Texas State Steel steel mill. My father and I would occasionally walk down the street on a Saturday morning and spend some time chatting with Buck. He was a smooth-faced man, already balding, with a rather skeptical attitude toward nearly everything. In later years he retreated to the countryside and built an even bigger fence around his house. But in me he may have recognized a kindred soul—a kid who idolized Edison and was constantly tinkering with any piece of machinery he could get his hands on. Buck had already donated to me an old cathedral-style radio, which I had promptly demolished down to the individual resistors and volume controls, learning much about radio construction in the process.

One day when we were visiting him, I told him I wished I could buy an oscilloscope. He wanted to know what an oscilloscope was, and when I told him, he said, “You know, that sounds like something Mr. Dowell might know about. He runs that little radio-TV shop down on Berry Street. Next time I’m in there I’ll ask him about it.” And then I forgot all about the conversation in the press of my fall semester at Lily B. Clayton Elementary.

But a few weeks later, Buck phoned. He’d spoken with Mr. Dowell, and it turned out that Mr. Dowell had an old scope he might be willing to part with. One day when we had time, he said we should go down there and talk to him.

By the time we could do that, it was winter. Finally, my father said he had time to take me down to meet Mr. Dowell and talk with him. So my mother made me put on a heavy coat and we got in the new blue VW Beetle my father had recently bought, and drove down to Mr. Dowell’s shop on Berry.

Mr. Dowell’s shop was in a small wooden shack, really, next to the Gospel Temple, a stucco monstrosity with a towering neon sign in front that some evangelist had erected in the 1930s. It had long ago been abandoned, and the whole neighborhood was beginning to go to seed, Mr. Dowell’s shop being no exception.

A bell jingled as we opened the glass door and entered the small shop. A counter ran almost the length of the whole room. The front windows provided most of the light in the place, and from where I stood I could see row upon row of shelves holding old radios, TVs, and the occasional appliance (irons, toasters), all in various stages of repair. The room had the faintly sour smell that free-standing gas heaters produced, combined with another aroma I have always associated with old radios. It was the slightly sweetish smell of warm beeswax, which was used to insulate and waterproof capacitors and transformers before World War II and the development of better plastic compounds. Whenever you soldered a capacitor covered with beeswax, you would get that smell.

Mr. Dowell was hunched over a radio chassis at a workbench behind the counter. He looked up when we came in and asked us what he could do for us. I wish I could describe him physically. But one tends to remember what one is interested in at the time the memory is formed. When I was ten, people were mainly just a means of my doing things with machinery and electronics. That sounds terrible to say today, but it pretty well explains a lot of what I did until I was an adult. And this attitude influenced what my memory recorded. Therefore, I can describe in great detail the tube socket Mr. Dowell showed me how to modify in order to repair an old radio that needed a tube which was no longer available. But if you ask me what he looked like, what his voice sounded like, or what conversations we had, I cannot tell you.

This is why engineers seldom make good novelists. Novelists need good imaginations, and the imaginations of engineers run in different courses.

At any rate, we asked to see the oscilloscope that Mr. Dowell might be induced to sell. He went in the back and hauled out a large steel-cased object. The case had what was known as a gray crackle finish—a method of painting that gave a textured or wrinkled surface to the paint. The front panel had white lettering on a blue background.

It was a Philco 5-inch oscilloscope. Like the TVs they were intended to help you repair, scopes were known by the diameter of the cathode-ray tube (picture tube) that produced the display. This one had a plastic graticule over the screen to aid in measuring the voltages and timing of the waveform.

I asked Mr. Dowell if it worked. Rather than answer, he plugged it in and turned it on. In a minute a wavy green line appeared on the screen. He handed me a cable with a pointed tip and told me to touch the tip. When I did, the screen display went crazy. “That’s power-line hum. Your body picks it up.” I was thrilled.

Then came the time to negotiate. I think he wanted forty dollars, but my father wangled him down to thirty (all I could save or borrow at the time) plus an offer for me to come help him some on weekends. To this day I don’t know whether this was something we did to get the price down, or whether Mr. Dowell offered to just teach me a few things and I persuaded my father to take me to the shop. Realistically, I don’t believe an elderly radio technician would think that a ten-year-old boy would be any help around his shop, and he would more likely look on the situation as glorified babysitting. But maybe I struck him as somebody who could really be of assistance, I don’t know. Be that as it may, I do recall that for at least a couple of weekends afterwards that winter, I spent all morning in Mr. Dowell’s shop trying to help him, before my father picked me up at lunchtime.

I wish I could write more about Mr. Dowell and his shop, but these memories are about all that I can recall. The shack was pretty cold even with Mr. Dowell’s single space heater running. I don’t remember ever seeing any customers, though a few may have wandered in. Even as early as 1965, demand for radio repairs was falling as the price of new radios fell and it became almost pointless to get an old one fixed. Either Mr. Dowell didn’t do much in the way of TV repair or he didn’t have that much TV business. But other than adapting a tube socket to get that old radio running again, I recall no details about anything else I did for him.

Finally, having fulfilled my term of indentured servitude, I came into possession of the scope. I happily took it home and installed it in a prominent place on my workbench, an old desk in my bedroom. Having that scope did more than any other single thing to help me understand what was going on in my circuits. I could actually see amplifiers amplifying, oscillators oscillating, and see what the sound of my voice looked like when I spoke into a microphone connected to the thing. It also impressed my friends, but that wasn’t the main reason I wanted it.

When the renter of our downstairs garage apartment moved out and my father had trouble renting the space again, I said I’d like the room for a lab. He consented, and so I moved my collection of Popular Electronics magazines, oscilloscope, power supplies, tubes, parts cabinets, and other miscellany to the single-room studio apartment, complete with bathroom, closet, and gas stove I could run in the winter to keep from freezing while I played with transistor circuits. The humidity made by the gas burners fogged up the windows in the winter, and probably contributed to the early demise of the high-voltage transformer in the scope. Whatever the cause, one day I turned it on and it didn’t work—no trace. I pulled the chassis out of the case and went to troubleshooting, which wasn’t hard when there was no high voltage. I eventually ended up mounting another transformer in the thing and hooking it in to substitute for the opened-up winding of the original.

It never worked quite as well after that, but I kept using it until I went away to college. After that, other scopes came into my life: first a foot-and-a-half-cube 3-inch military surplus unit, and later an old portable Tektronix scope that I eventually gave to a young man who I thought might be interested in electronics. He wasn’t, as it turned out, and when we moved from Massachusetts to Texas in 1999, I realized that practicality finally outweighed sentiment. It was time to get rid of the Philco scope, which wasn’t even any good as a collector’s item because I had modified it so extensively. My last sight of it came when I left it on a pile of trash at the city dump. This was in the days just before it became easy to sell things on eBay, and I was in a hurry to move. But I still have the manual somewhere.

And what happened to Mr. Dowell? Some time between 1965 and the eighties, his shop closed and the shack was torn down, along with the Gospel Temple, and replaced by a strip mall that has itself gone into decline since.

The whole enterprise of electronics repair has been transformed beyond recognition, limited now to high-dollar items such as flat-screen TVs, and regularized by the fact that nearly all repairs are under warranty agreements that require the device to be returned to an authorized repair shop. The manufacturers impose training and other requirements on shops, which now have to meet standards that were not enforced earlier. This has had the effect of making most of them disappear. The remaining few shops are in large cities and have to operate in a way that satisfies both the customer and the manufacturer. Hiring ten-year-old assistant technicians, even for in-kind payment, is not in their purview, I suspect.

I am pretty sure Mr. Dowell has gone to that Great Repair Shop in the Sky, otherwise known as purgatory, if not to a worse reward. I knew nothing of his personal life and we never discussed religion. But he did at least one kindness that I know of: putting up with a nosy, inquisitive, and not very helpful boy, and selling him his very first oscilloscope. For these things, I thank him.

Saturday, July 30, 2011

Stereo Typing: Radioteletypes Recalled

Many old films about the newspaper business feature a newsroom scene with rhythmically clunking teletypes pounding out yellow reams of copy. The occasional closeup in which dramatic words appear on the paper as if by magic told the viewers nothing about how a teletype machine actually worked. Nor should it have. I have long outgrown the private misconception that most moviegoers were just like me, and would have enjoyed ten-minute disquisitions on the details of any technology featured in a film, while the plot ground to a halt. But one day in my teen years, still under the spell of that delusion, as I perused the remoter regions of a surplus-equipment warehouse I was delighted to find an army-green metal box with a keyboard sticking out the front. Inspection proved the device to be an old Kleinschmidt-brand tape-printing teletype, probably scrounged from a small-town telegraph office two or three decades before (this was about 1975). I probably paid about ten bucks for the thing, and the owner was glad to get it off his hands. It weighed a ton and I could barely get it in the tiny trunk of my VW Beetle, which was noticeably down at the head as I drove home with my prize.

My mother, accustomed to seeing all manner of indescribable junk brought home after my surplus jaunts, was nonplussed at hearing I had procured a teletype machine. “Just don’t get any oil on the carpet,” she said. The thing did have a characteristic smell, composed of equal parts of machine oil and burned carbon brushes. After hoisting it up on the workbench in the garage, I removed the case and pondered my purchase.

Back in the 1920s, teletype machines were as cutting-edge as Kindles or 3-D Nintendos are today. They spelled eventual doom to the old-style hand-copying telegraph operator, who had been the mainstay of the telegraph business since its inception in the 1840s. With a teletype, one skilled typist (typically a woman) could do the work of several hand operators. Plus which, she could type out copy in advance on paper tape for batch transmissions, and the paper tape copy disgorged by the receiving teletype could simply be pasted on a telegram form and delivered, almost untouched by human hands (except at the transmitting end). So by 1950, as Western Union experienced its own “peak message” year and saw its business head for eventual decline, teletype use was nearly universal.

How did a teletype circuit work? As I learned by reading old radio-amateur books, the teletype was simply an automated form of the old make-and-break telegraph key. The original Morse code consisted of dots (short electrical pulses) and dashes (by convention, three times longer than dots) in specific patterns. The teletype used the same idea, only mechanized and synchronized so that once a human being at the transmitting end pressed the key for a given letter, no further human intervention was required.

Suppose the letter pressed was “R”. Here’s what happened next. Pressing any key released a cam follower which opened a switch for a few milliseconds. Then for the next five equal intervals of time, the cam opened and closed the switch in this sequence: open-close-open-close-open. Then the switch closed and stayed that way until the next keystroke. By convention, the presence of current was called “mark” and the absence “space.” All characters began with a single space pulse.

My teletype machine used what was called a “5-bit” code. During each of the five precisely timed intervals, the switch was either open or closed. This allowed the transmission of 25 = 32 unique characters—in other words, the alphabet plus a few more symbols. Numbers had to be sent after the transmission of a special “uppercase” signal that shifted the receiver carriage to uppercase mode.

The same kind of telegraph wires that Morse & Company used carried teletype signals too, at least to the smaller stations. The transmitting equipment consisted of a high-voltage power supply—100 volts or so—with enough series resistance to limit the closed-circuit current to 20 mA. In this way, about the same current flowed through the circuit regardless of the length of line, and all telegraph circuits connecting different stations along a line were in series. In that way, transmissions from one circuit-interrupting station could be received by all the other stations along the line.

At the receiving end, things really got interesting. My teletype was both a transmitter and receiver, which was fortunate, because I would have been hard put to come up with a receiver for a transmit-only unit or vice versa. The transmitted current went through an ordinary relay coil that operated an adjustable armature. As soon as the armature was released following the initial space pulse, a rotating cam began to throw a kind of feeler lever at the armature five times. Each throw corresponded to the most likely time that a mark or space was present. Depending on whether the armature was pulled in (“mark”) or released (“space”), the feeler lever landed on one side or another of the armature. In sequence, this landing on one side or the other shoved five stacked semicircular bars of metal slightly to the left or right of their original positions, before the character was received.

The bars of metal were arranged in a semicircular basket shape rather like an old-fashioned manual typewriter, and rods connected to each of 32 typebars rested against the edges of the semicircular bars. Each semicircular bar had precisely positioned notches cut in it in such a way as to decode the particular character sent by the transmitter. For example, when “R” was received, the bars were pushed left-right-left-right-left, going from top to bottom of the stack. At the end of the character transmission, another mechanism pressed all the typebars against the five semicircular bars. The slots in the semicircular bars were cut so that only one typebar—the “R” bar, in this case—fell outward, because all five of the slots in the five sheets of metal lined up, and none of the other bars had all five slots clear. So for each character, only one of the 32 typebars could clear all five movable slotted bars and get to strike its character. It was rather like a complicated lock mechanism that rearranged itself every time a character was received, and only one key—the correct character typebar—would fit the lock each time. Yet another mechanism used the fact that the “R” bar fell outward to actuate the typebar carrying “R,” and only that typebar, to strike the paper tape. That is, if one had a paper tape to strike.

That was one of my many problems in getting the thing to run. I wasn’t about to sit around with a roll of calculator paper and manually cut a long strip of paper of the right width. After much experimentation, I discovered that ordinary (at least, ordinary back then) quarter-inch reel-to-reel magnetic tape fit through the tape-feed mechanism with only an occasional tape jam. It wasn’t too easy to read the dimly printed characters struck from the worn-out ribbon onto the dark-brown acetate tape, but after a lot of fiddling, I was able to strike a key and get the corresponding letter to print.

I left out a lot of other stuff I had to do first. One reason the machine was so cheap, I discovered after taking it home, was that it had a 110-volt DC motor. That’s right, not AC, but DC. It took me a while to come up with a power supply beefy enough to provide the amp or so that the motor needed.

Then there was the governor, a large disc-shaped thing on one end of the motor shaft that spun around dizzily whenever the motor was powered up. Especially if more than one teletype was involved, you had to ensure that the motor in your machine was turning at exactly the same speed as the other guy’s motor, if the marks and spaces were going to line up properly. With AC motors, this is a simple matter of using a type of motor called “synchronous,” but mine wasn’t that way at all. It had some kind of weird centrifugal switch that would gradually cut in and out as the motor reached the proper speed. I’m not convinced it ever really worked properly. As long as I was transmitting only to myself, it didn’t matter because the same machine was doing the sending and receiving. But when I got more ambitious and decided to try and receive radioteletype signals, things got even more complicated.

Back then, not only did radio amateurs do a fair (non-profit) business in the transmission of what was termed “RTTY” contacts, but there was a great deal of international short-wave news traffic transmitted by radioteletype. The notion of reading that news right off the air fascinated me, and I spent most of a spring vacation during college trying to pick up RTTY transmissions. Such was the life of a truly dedicated nerd in those days.

There were two main problems in the way of my getting the radioteletype signals to print. First, I had no way of measuring what the actual speed of the motor was, so it was a matter of guessing an adjustment and hoping it would have the right effect. Second, and worse, was the RF interference that the DC motor produced. It had brushes that sparked and flashed and smelled like the air after a thunderstorm, and that plus the contacts in the governor trashed most of my attempts at reception of any but the strongest signals. Finally, after many fruitless tries, one afternoon I tuned in a strong commercial RTTY station that I’d gotten familiar with, and was rewarded with the sight of two or three sentences’ worth of genuine pirated news—in Spanish. It was probably some South American regional service.

Having achieved that triumph, I gradually lost interest in the thing. My amateur radio license lay a few years in the future, so I had no way of actually using the thing for two-way communications unless I convinced a friend to buy another teletype and we rigged up a private telegraph line. In suburban Fort Worth in 1975, this was not practical.

The year after I bought the teletype, I flew home from Caltech during the spring break of my sophomore semester. My grandmother (my father’s mother) was very ill with stomach cancer, and we planned a visit to her house the day before I was to fly back to California.

I had spent most of the week trying to get my teletype to work, and had succeeded in getting the Spanish-language news copy just a day or two earlier. In my myopic world, this was the big news, and I am afraid that the teletype might have been the main subject of my conversation to her that day. Then I asked her how she was doing. By her looks, she was doing pretty awful. She was propped up on a pillow in her bed, and when she raised her arms to hug me, her flesh hung limply from her bones.

I do not remember much about what she told me, except for one thing. I do not recall how the subject came up, but she began to talk about the time she visited the 1904 St. Louis World’s Fair, and what a good time she had there. She was probably about eighteen in 1904, about the same age I was at the time we spoke. Maybe that’s why she brought it up. I don’t remember. So the last thing I talked to her about was some old piece of machinery I had managed to get going, to no one’s satisfaction or benefit other than my own. And the last thing she told me about was the time she saw a glittering new vision of a glittering new country in a glittering new century, when she was glittering and new herself.

The next day, my father and I got up early so we could get to Love Field in Dallas in time for my flight. For reasons having to do with packing as much as formality, I always flew in my suit in those days, so I suited up and got in the car. We didn’t say much on the drive over, except that my father talked about how we might handle the eventuality of Big Mother’s death. (That was what all her grandkids called her, in the old Southern tradition.)

We got to the airport and had an hour or so to wait. This was long before terrorist-inspired inspections and metal detectors, so he and I had the run of the place. At one point I had to go to the bathroom. As I stood there taking care of business, I heard the PA announcer page my father for a phone call. That could mean only one thing.

I rushed outside as fast as I could and caught up with him as he was running for a courtesy phone in the middle of the large open two-story lobby or atrium they had back then. Once on the phone, his face looked like he was speaking with a past-due loan customer. He listened a moment and broke in to say, “Is she dead?” She was.

My Aunt Fanny, who lived with Big Mother, had gotten up that morning and found that her sister had died during the night. As she recalled later, she “had her little emotion,” as she put it, then called my mother after we had left for the airport. My mother called the bank, thinking maybe they could get hold of my father faster, and a secretary there had the notion to call the airport. Thus were emergency messages conveyed in the days before cellphones.

Needless to say, I missed the plane and stayed for the funeral. At times during the proceedings, I recalled something that happened the night before she died. My spiritual state at that time might be best described as conservative-agnostic. I knew I was a conservative politically, but as for God and all that, why, I wasn’t sure. But I knew Big Mother was sure there was a God. In the spirit of Pascal’s wager, I had been in the habit of praying a highly ritualistic prayer of my own invention every night before I went to bed. This was just in case God happened to be there, so that at least I would have some prayers to my credit at the great reckoning. (The “Now I lay me” prayer my mother had taught me I had long since discarded as morbid and childish.) But that night, after seeing Big Mother in such pain, I put aside all ritual and asked God, in my mind, either to make her well or take her to Himself. And maybe it is retrospective revision of memory, but I seem to recall a sense that something, or someone, was there listening to my thoughts, and as soon as I finished praying, moved off into the moonlit night. And the very next day, she was gone.

Like most (not all) alleged miracles, this one is susceptible to a number of naturalistic explanations. People can will themselves to live a few more days if a particular event has meaning for them. Perhaps this is why Thomas Jefferson died (or chose to die?) on July 4, 1826. So maybe my grandmother hung on a few more days to see me off to school before she let go. I will never know for sure in this life.

That situation—the answered prayer and the end of a life lived wholly in God’s care despite my blind ignorance of its depths—made an impression on me that never left me. I now believe in the God of my grandmother. If there is any justice in the universe, she is there with Him, and in the communion of saints we will be able to talk again. Only this time, I won’t bring up teletypes. At least, not right away.