April 1960 Popular Electronics
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"So if I can work out a really efficient way of changing part
of this wasted noise into electrical energy, it can be charging
batteries and taking some of the load off the plane's generating
plant." That passage, from the April 1960 Carl and Jerry
adventure story, reads like a modern day energy harvesting project.
Each month Popular Electronics included an electronics saga
that normally included some high tech sleuthing by the teenagers
a la the Hardy Boys. This is a particular favorite of mine because
it involves a radio controlled airplane model. BTW, according
to the Google translator, the title of this story is "The Electronic
Carl and Jerry: El Torero Electronico
By John T. Frye
As Carl stepped through the open door of the electronic laboratory
he shared with his pal, Jerry, in the basement of the latter's
home, his ears were assailed by a loud, piercing, unwavering
tone. It was coming from a hi-fi speaker in one corner of the
room, and Jerry was crouched over some electronic equipment
directly in front of the speaker.
"What are you doing?" Carl shouted. "This is no day to be
messing around indoors. Spring is busting out all over out there.
And shut off that blasted noise!"
Obediently Jerry reached out and shut off the sine-wave generator
connected to the input of the hi-fi amplifier.
"I'm experimenting with converting sound energy into electrical
energy," he explained. "Look at this sound level chart that
appeared in the February 1959 issue of Electronics World and
at this one prepared by Bell Telephone Laboratories. See: the
audio power in peak sounds from a seventy-five piece orchestra
is 65 watts. The sound of an ordinary airplane at eighteen feet
is better than 20 db, or 100 times more powerful; so it must
put out close to 6500 watts of sound. Think how much more sound
power is put out by one of those six-engine jets at the air
base. When they take off, you can't hear yourself think."
"So if I can work out a really efficient way of changing
part of this wasted noise into electrical energy, it can be
charging batteries and taking some of the load off the plane's
"How're you starting out?"
"I'm trying to find the most efficient device for translating
sound into electricity without worrying about the actual efficiency
percentage of the device. Measuring actual sound power is real
tricky even when you have elaborate sound-measuring equipment
and a sound-deadened room. By measuring the voltage developed
across the eight-ohm voice coil of this speaker by my 1000-cycle
tone, I'm setting the electrical power fed into the speaker
at exactly one watt. I figure the speaker has an efficiency
of between five and ten percent; so I estimate that the sound
power output is only around one-fifteenth of a watt or thereabouts.
"This transducer I'm trying first is a sound-powered phone.
As you can see, it's mounted exactly a foot away from the speaker
and directly in front of it. These sound-powered phones arc
designed to be transducers of sound into electrical energy and
electrical energy into sound. When two of the units are connected
together, sound striking the diaphragm of either moves an attached
coil in a strong magnetic field, producing currents in the coil.
These induced currents travel along the connecting wires and
flow through the coil of the other unit, causing it to vibrate
its diaphragm and produce sound again. Notice that all the power
used - and you can carry on conversations up to twelve miles
with a pair of these phones - is produced by sound waves.
"Any other transducers I use, such as sound-powered units
working on a slightly different variable-reluctance principle,
speakers, crystal units, etc., will be mounted in the same position
as this moving-coil unit. They will be subjected to the same
dynes per cm2 of sound power as long as I keep one
watt of 1000-cycle tone feeding into the speaker. This will
allow me to compare relative efficiencies by simply taking into
account the pickup area of my transducer and noting the electrical
power developed across a resistive load. Of course, impedances
between the transducer and the load must be carefully matched
to develop maximum power. That's what I'm doing now."
"Sounds like a real neat idea, but let's save it for a rainy
day," Carl suggested. "Come along and help me tryout my brand-new
radio-controlled plane. The thermometer is up to 75 out there,
and the buds are bursting like popcorn."
Jerry needed little urging, and a half hour later the boys
were parking their bicycles along a narrow dirt road running
alongside a large pasture with a single tree growing in the
center of it.
Carl's plane was not a sleek modern aircraft. Instead, it
was a sturdy old-fashioned biplane model of the sort he had
seen crop-dusters using in the South. The large wing area permitted
it to stay in the air at slow speed, and an oversize engine
gave it lots of power for hedge-hopping tactics. Carl had spent
a great deal of time - and no little money - designing the most
responsive and complete remote control possible for maximum
maneuverability. It was his intention to fit a smoke emitter
in the plane and give a realistic demonstration of dusting procedures
at a model airplane meeting coming up in a couple of months.
Carl handled the controls, and Jerry hand-launched the plane.
Right from the start it performed beautifully. Carl first sent
it high above the pasture to test it out; but when he saw how
quickly and smoothly it answered every electronic command, he
brought it down until it was skimming only a few feet above
the fresh green sod.
"What a sweet-flying job!" he chortled happily. "Watch this,
old buddy; watch me put it in a tight circle around that tree."
The little plane lifted easily to the top of the tree and
went into a tight banked left turn. At this moment there was
a terrific rumbling roar right in the boys' ears, and Carl was
so startled that he dropped the control box. Standing in front
of the boys, with only the fence between, was a red-eyed black
bull emitting a low earth-shaking bellow through his flared
"Wow!" Jerry exclaimed shakily; "what a beast! I'm sure glad
that fence is there. He must have sneaked up on us while we
were watching the plane."
"Where is the plane?" Carl asked as he snatched up the control
box and anxiously scanned the empty sky. "Oh, oh! he groaned.
"There it is in the tree."
Sure enough, the little plane was resting in the upper branches
of the tree with its motor still snarling away. Carl cut the
motor off with the control box, and the two boys tried to drive
the huge animal away by shouting at him and waving their arms.
But this only seemed to add to the bull's ill temper. Finally
they went down the road a short distance and hid in the side-ditch.
The bull eventually calmed down and wandered over to the
far side of the pasture. Stealthily Carl and Jerry crawled under
the barbed wire and quietly approached the tree. They were almost
to it when the beast spotted them. Its tail went up into the
air, and it came in a lumbering run straight for them.
The tree was a lot closer than the fence, and both boys
started to climb it simultaneously. Since the trunk was only
about a foot in diameter, this caused some confusion. They made
it up to the branches, though, and as they sat there, breathing
hard and staring down at the bellowing animal below, Jerry said
"You and your superior muscles! What's the big idea of climbing
over the top of me? If there's one thing I can't stand, it's
"I didn't mean to climb over the top of you; I had help from
the bull," Carl explained, tenderly rubbing the area of his
hip pocket. "I was having a little trouble climbing, though,
with you standing on my face. I'm going up to get the plane.
You keep Ferdinand entertained."
In a few minutes Carl had inched his way back down to Jerry's
level with the plane in his hands. "Not hurt a bit!" he gloated.
"When I dropped the control box, the plane must have pulled
up in a stall and then pancaked into the tree. We're lucky."
"Oh, we're lucky, all right!" Jerry exclaimed sarcastically.
"We have a choice: we can either sit up here in this tree and
freeze to death tonight or we can let that bull make shish kebab
out of us on his horns."
"It's not that bad - I hope," Carl comforted. "We'll get
out of this some way. He'll get tired after a while and wander
away. Let's be quiet and see if he doesn't forget us."
The boys remained absolutely still for half an hour, but
the bull did not calm down. He circled around and around the
tree, pawing the earth and throwing great clods of soft turf
up over his back while slobbers ran from his bellowing mouth.
"Gee, what a grouch!" Carl finally exclaimed as he looked
anxiously at the sun touching the horizon. "I never realized
what 'bull-headed' really meant until now. He's not going to
cool off. We've got to think of something else."
"You might jump out of the tree and sprint for the fence,"
Jerry suggested. "You're pretty fast and may be able to out-run
him. While he's chasing you, I'll carry the plane to the fence
on the other side of the pasture."
Before Carl could answer, the bull thrust a sharp pointed
horn into the trunk of the tree and ripped off a great slab
"Let's think of another idea," Carl said as he tightened
his grip on the quaking limbs. "What we really need is a toreador
to coax him away from us."
"That's it!" Jerry exclaimed: "an electronic toreador! You
got any red cloth about you?"
"I don't think so," Carl answered; "but if you think I'm
going to get down there and wave a red flag in front of that
couple of tons of pure cussedness, you've got another think
"That lining of your jacket is red silk," Jerry observed.
"Take my pocket knife and cut out a chunk a couple of feet square."
"Mom will kill me if I do."
"Would your mother rather have a whole jacket or a son with
a whole hide? Get with it while I unravel a sock to get a piece
of strong thread. We'll fasten the piece of red cloth to the
plane with about ten feet of thread. Then we'll make the plane
drag the cloth back and forth in front of Ferdinand. If we're
lucky, we may be able to coax him away from the tree long enough
for us to reach the fence."
Carl butchered a large square of cloth from the jacket lining
and fastened it with the thread to the plane at a point where
the drag would have a minimum effect on the plane's maneuverability.
Then Jerry inched out on a limb until he could launch the plane
in the clear. The motor was started and, at a word from Carl,
Jerry gave the little plane a strong push. For an anxious moment
it swooped down until the piece of cloth brushed the grass,
but then it started climbing and sailed around the pasture easily.
Carl worked the control box expertly, and the little plane
came back toward the tree carrying the bright red cloth about
three feet above the ground. The animal turned his great head
toward the sound of the purring motor and spied the approaching
red cloth. With a bellow of anger, he charged it.
The plane went into a steep climb and carried the cloth out
of reach; then it wheeled about and came back and actually dragged
the bright fabric over the back of the startled bull. As it
flipped off his horns in front of his eyes, he charged fiercely
after it. Carl throttled the motor down until the plane was
almost stalling and flew a zigzag course that kept the red cloth
tantalizingly in front of the animal's nose until he was led
into a far corner of pasture; then both boys leaped to ground
and ran for the closest fence.
Carl, as he ran, still kept an eye on the little plane and
used the control box to keep it flying. The bull was so engrossed
with his new "enemy" that he did not notice the boys' escape
at all. When they were safely across the fence, Carl brought
the little plane sailing to them. He handed the control box
to Jerry and had him put the plane into a tight circle while
he caught the dangling piece of red cloth and broke the thread;
then he took over and brought the plane in for a smooth landing
on the narrow dirt road.
"Well," Jerry observed, getting astride his bicycle; "that's
that, and we'd better be getting home or we'll miss supper."
"Yeah," Carl agreed as he shot a malevolent look at the snorting
bull, once more just on the other side of the fence; "and I
just hope we have beefsteak!"
Jerry: Their Complete Adventures is now available. "From 1954 through 1964, Popular Electronics published
119 adventures of Carl and Jerry, two teen boys with a passion for electronics and a knack for getting into and out of trouble
with haywire lashups 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
- Abetting or Not? - October 1956
- Electronic Beach Buggy - September
- Extra Sensory Perception
- December 1956
- Trapped in a Chimney
- January 1956
- Command Performance -
- Extracurricular Education,
- Treachery of Judas, July 1961
- The Sucker, May 1963
Stereotaped New Year, January 1963
- The Snow Machine, December 1960
Extracurricular Education, July 1963
- Slow Motion for Quick Action, April
- Sonar Sleuthing, August 1963
TV Antennas, August 1955
Succoring a Soroban, March 1963
"All's Fair --", September 1963
Operation Worm Warming, May 1961
The Crazy Clock Caper, October 1960
Two Detectors, February 1955
Tussle with a Tachometer, July 1960
- Therry and the Pirates, April 1961
The Sparkling Light, May 1962
Pure Research Rewarded, June 1962
Hot Idea, March 1960
- The Hot Dog Case,
- A New Company is Launched,
- Under the Mistletoe, December
- Electronic Eraser, August 1962
- Blubber Banisher, July 1959
"BBI", May 1959
Ultrasonic Sound Waves, July 1955
The River Sniffer, July 1962
Ham Radio, April 1955
El Torero Electronico, April 1960
Wired Wireless, January 1962
Electronic Shadow, September 1957
Elementary Induction, June 1963
He Went That-a-Way, March1959
Electronic Detective, February 1958
Aiding an Instinct, December 1962
Posted July 16, 2012