December 1955 Popular Electronics
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Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
Were strings of miniature Christmas tree lights not available for purchase in 1955? This adventure of "Carl & Jerry" seems to imply that was the case since it concerns the design and constructions of such a circuit using low voltage panel lamps (light bulbs). Although usually the two techno-teenager are co-conspiring on various tasks of high tech sleuthing or radio-related pursuits, in this case it is Jerry who has been doing the hard work. Author John Frye might not know how prescient he was when describing the two inventions he conjured up for Carl and Jerry. The first is the aforementioned miniature Christmas light string and the second is a voice recording device that can capture a short message and then quickly play it back. The playback scheme involves kids reciting their Christmas wish list to a fake Santa Claus and then having him read it back to them in a different voice (slowed down). Regarding the light strings, note that they are incandescent bulbs wired in series so if one goes out, they all go out. Most, if not all, Christmas light strings these days are wired such that if one burns out, the rest stay on. Can you remember the old days of needing to try a known good bulb in every socket until you happened to find the right one? Unless you were savvy enough to test the bulb with an ohmmeter instead of sequentially swapping bulbs, you could have a real headache if more than one bulb happened to be burnt.
Carl & Jerry: Santa's Little Helpers
By John T. Frye
The cozy warmth of the basement laboratory felt good to Carl as he stepped in out of the crisp December weather. He removed his steaming glasses and peered owlishly at his buddy, Jerry, sitting at the workbench busily engaged in doing something with a large box of dial lamp bulbs, several short lengths of insulated flexible wire, some little jars of colored liquid, and a soldering iron.
"What're you up to ?" Carl demanded. "Getting homesick for the June fireflies and trying to make up some synthetic ones ?"
"That's not too far off," Jerry grunted, without looking up. "I'm cooking up some miniature Christmas tree lights for our tree."
"How ?" Carl asked.
... Santa will be quite willing to take the frozen message out of his ice-chest and thaw it out so that the child can hear his own voice giving the Christmas list - over the small speaker connected to the tape recorder .
"Well, what I'm really doing is connecting 20 of these No. 40 panel lamps in a series string to be connected across the light line. That way, the 120 volts in the line divides up so that each bulb has six volts across it. Since the bulbs are rated at 6 to 8 volts, this should allow them to operate for a long time without burning out. I could just as well have used No. 47 bulbs, which are identical electrically but have bayonet instead of screw bases. However, I was able to buy this large box of No. 40's at a bargain. For that matter, No. 44 bulbs could also have been used to get a little more light; but since they draw 250 milliamperes of current instead of the 150 ma. drawn by the No. 40's and get quite a bit hotter, the lower-current bulbs will be safer to use."
"Since No. 40's and No. 47's draw the same current, you could mix them in the same string; but No. 44's could not be mixed with either of the other two types. Check?"
"Check," Jerry nodded.
"How far apart will the bulbs be?"
"A foot and a half. That's why I'm cutting these 18" lengths of wire, stripping about 1/8" of insulation off both ends, and then tinning the ends. When this is done, I'll simply solder a tinned wire end to the tip of one of the bulbs with the wire pointing straight down away from the bulb. On the other end of this wire, I'll solder the screw base of a second bulb with the glass bulb pointing away from the wire. A second wire will be soldered to the tip of the second bulb and dressed parallel to the other wire. The base of a third bulb, lying next to the first bulb, will be soldered to the free end of this last wire, and so on. When I get through, I'll have a row of ten bulbs at the top and ten bulbs at the bottom all neatly connected in series by zigzag lengths of wire. Two longer lengths of wire can be run from an a.c. plug to the base of the first bulb and the tip of the last one to make the string ready to be connected to the line."
"You're not going to leave those 'hot' connections exposed, I hope," Carl said with a quick frown.
"Well hardly! Each bulb base will be completely covered with a neat wrapping of this thin plastic tape that extends from well up on the glass to down below the tip and holds the two wire leads firmly together. The tape adds very little bulk, really sticks, and is rated at several thousand volts of insulation."
"Won't clear bulbs look kind of monotonous?"
"They're not going to be clear. That's why I bought this dial lamp coloring kit. It has little jars of liquid red, green, blue, and amber coloring material as well as a jar of solvent. All I have to do is dip a bulb in the proper coloring solution, and presto, I have a red, a green, a blue, or an amber colored bulb. If I get tired of one color, I can use the solvent to remove it and start all over. I think I'll make up several strings and dip all the bulbs of one string in the same color. After all, a whole string draws less than 20 watts; so power consumption is no item. Just once I'd like to see a tree really full of colored lights."
"Are you just dreaming about how these lights will look or have you seen such trees ?"
"I've seen them. John Crump, who works in the engineering department of the RMB Company, has been using strings like these for five years, and they really look swell. It's surprising how much light those little bulbs throw; yet they are small enough so that they really decorate a tree instead of covering it up. What's more, they are the easiest things in the world to put on the tree or take off. They are so light that they can be put on the tips of the smallest branches."
"How about burn outs? Replacing a bulb would require unwrapping the tape, unsoldering the wires, and soldering in a new bulb. You could, of course, locate a burned-out bulb with a pair of insulation-piercing probes and an ohmmeter; but it seems to me that would be a good bit of trouble if these bulbs burn out as fast as the common series-string type do."
"That's the good part: they don't. John tells me he has been using the same half-dozen strings for five years, and not a single bulb has conked out in all that time. He mentioned one rather funny thing, though. He says the bulbs colored blue get noticeably hotter than those colored red or amber. We decided that the blue coloring doesn't transmit the heat radiated by the filament as well as the red and amber coloring does."
"Okay, I'm sold, and you're a genius," Carl exclaimed. "How's about helping me with my Christmas problem? Two years ago Dad and I built a life-size Santa and put it out in the front yard. The eyes of Santa lighted up whenever he was awake-which oddly enough was just about time the little kids came past on the way home from school - and they thought he was real cool. Last year I put an intercom unit in Old Nick's tummy, and he was even more popular because he could listen and talk back, although I'm afraid his 'ho-ho-hoing' was a bit on the treble side. This year I've got to come up with something new. Modern kids demand constant progress, and unless Santa has learned some new tricks since last Christmas, they're going to think the old boy is pretty stupid."
"Hm-m-m, we should be able to dream up something," Jerry murmured slowly as he closed his eyes to think better. "I think I've got it! Use extension cords to put the mike of the tape recorder and a small speaker connected to its external speaker jack inside Santa along with the intercom unit. Then you can use the intercom to persuade each kid to tell Old Santa what he wants for Christmas. As he starts to talk, you take down the list on tape."
"I'm with you so far. Go on."
"Well, you could put out a spiel to the effect that Old Santa wants to be real sure he remembers the list of each kid. Since he is really modern, he has worked out a system whereby he quick-freezes the words of the child as he hears them and then stores the frozen messages away in his ice-chest until he is ready to pack his bag for the Christmas Eve trip. If any child doubts all this, Santa will be quite willing to take the frozen message out of the ice chest and thaw it out so the child can hear his own voice giving the list - over the speaker connected to the tape recorder, naturally. You'll need a couple of sound effects to go along with this business. There should be some sort of tinkling sound to accompany the 'freezing' of the messages, and then there ought to be a sizzling sputtering sound when they are being 'thawed out'."
"Now, wait just a little minute. You know as well as I do how hard it is to locate a short recorded section on a tape when you're in a hurry. By the time I found a particular message and thawed it out, the kid himself would be frozen in his tracks waiting to hear it."
"I've thought of that, too. Don't try to record all the messages on one long roll of tape. Instead, cut up a roll of inexpensive tape into 5' lengths and hang them neatly over a tie rack. Then, when a child wants to tell Santa all about it, you simply thread the end of one of these tapes into the recording slot and between the pressure rollers. While you are recording, the tape will simply feed through and either bunch up on top of the recorder or slide off on the floor. Five feet of tape at 3 3/4 inches per second will give each kid about 15 seconds to make his wants known - which is plenty long enough unless his parents are richer than yours and mine are. As the recording is finished, write the child's name on the back of the leading end with a china marking pencil and hang it up so his name can be easily read. Then, when any moppet wants proof that his message to Santa is still safely on file, you can pick out the proper tape quickly and start it through the recorder."
"What a brain!" Carl exclaimed admiringly, as he roughly brushed Jerry's flat-top haircut. "And I've got a little scheme of my own. After Christmas is over, we can take those recordings and have them rerecorded on small disc records and sell them at a good profit to the parents of the children as keepsakes."
"We could, but I'm sort of agin it," Jerry said slowly. "Maybe the old Christmas spirit has got me, but somehow I don't want any part of commercializing Christmas any more than it is. If any parents want to have recordings made at their own cost, that would be quite all right; but let us just take our reward in the form of the fun we'll have amusing the children."
"Right!" Carl quickly agreed, "and I'm ashamed I even thought of it."
Posted December 19, 2019
Carl & Jerry: Their Complete Adventures is now available. "From
1954 through 1964, Popular Electronics published 119 adventures of Carl Anderson and Jerry Bishop, two teen boys with
a passion for electronics and a knack for getting into and out of trouble with haywire lash-ups built
in Jerry's basement. Better still, the boys explained how it all worked, and in doing so, launched countless
young people into careers in science and technology. Now, for the first time ever, the full run of Carl
and Jerry yarns by John T. Frye are available again, in five authorized anthologies that include the
full text and all illustrations."
Carl & Jerry Episodes on RF Cafe
- Pi in
the Sky and Big Twist, February 1964
Bell Bull Session, December 1961
Cow-Cow Boogie, August 1958
Picture, June 1955
- Electronic Eraser,
- Electronic Trap, March
- Geniuses at Work, June
- Eeeeelectricity!, November
- Anchors Aweigh, July
- Bosco Has His Day,
- The Hand of Selene,
- Feedback, May 1956
- Abetting or Not?, October
- Electronic Beach
Buggy, September 1956
- Extra Sensory
Perception, December 1956
- Trapped in a Chimney,
- Command Performance,
- Treachery of Judas, July
- The Sucker, May 1963
- Stereotaped New
Year, January 1963
- The Snow Machine, December
Education, July 1963
- Slow Motion for
Quick Action, April 1963
- Sonar Sleuthing, August
- TV Antennas, August 1955
- Succoring a Soroban,
- "All's Fair --", September
- Operation Worm Warming,
Santa's Little Helpers - December 1955
Two Tough Customers - June 1960
Transistor Pocket Radio, TV Receivers and Yagi Antennas, May 1955
Stomping, March 1962
- The Blubber Banisher,
- The Sparkling Light, May
- Pure Research Rewarded,
- A Hot Idea, March 1960
- The Hot Dog Case, December
- A New Company is Launched,
- Under the Mistletoe,
- Electronic Eraser,
- "BBI", May 1959
- Ultrasonic Sound Waves,
- The River Sniffer, July
- Ham Radio, April 1955
- El Torero Electronico,
- Wired Wireless, January
- Electronic Shadow,
- Elementary Induction,
- He Went That-a-Way,
- Electronic Detective,
- Aiding an Instinct,
- Two Detectors, February
- Tussle with a Tachometer,
- Therry and the Pirates,
- The Crazy Clock Caper,