May 1961 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
When becoming a licensed Ham a few years back, I learned that
when broadcasting over amateur bands, the FCC requires you to
transmit your station identification at the beginning of each
session and then at least once every ten minutes. I hate to
nit pick a Carl & Jerry story, but in this episode John
Frye's intrepid electronics hobbyist duo rigs up their basement
'shack' to automatically transmit the letter 'A' in Morse code
as a beacon signal to test reception in a cave. A timer would
start the broadcast and it would run continuously for half an
hour. Maybe things were different in 1961. The experiment intended
to test a signal's ability to propagate through the Earth rather
than through the air. It is an interesting twist on the skin
effect of high frequency signals along a conductor. As you might
suspect, the plan did not go exactly as intended, requiring
Carl and Jerry to apply a bit of radio knowledge to get themselves
out of peril.
Spoiler Alert: This story comes
ironically right after posting the item about engineers using
balloons to send an
antenna wire up through a smokestack.
Carl & Jerry: Operation Worm Warming
By John T. Frye W9EGV
Carl and Jerry were riding along the river road on a beautiful
afternoon in early May. Carl was driving, and Jerry was sitting
beside him holding a compact battery-operated 75-meter transceiver
on his knees. The bright day seemed all the brighter because
it had arrived after almost a solid week of heavy rain.
"Jer, do you think we'll be able to hear that transmitter
back in our laboratory?" Carl asked.
"I'd hate to say," Jerry answered.
"We'll only be four or five miles from it, and it'll be running
a hundred and fifty watts input; but a transmitting antenna
consisting of the outside shield of fifty or sixty feet of RG-8/U
coax cable running inside a sewer isn't the best radiator in
the world. You said the signal was only S3 at your place right
"But from what I've been reading," he continued hopefully,
"it's barely possible we may be able to hear the signal down
in that limestone cave along the river. Anyway, if we can't
hear the signal, we can do some plinking with your .22; so the
afternoon won't be wasted."
"That coax pushed into the basement drain a lot easier than
I expected," Carl observed; "and it certainly loaded the transmitter.
What time did you set the timer to turn on the transmitter and
start the automatic keyer?"
"Three o'clock. That will give us plenty of time to rig up
an antenna inside the cave. The transmitter will send 'A' over
and over for a full half hour before shutting itself off."
"Has anyone had much luck sending radio signals through the
"Well, in May, 1959, the
Space Electronics Co. people sent a message from an abandoned
borax mine at Boron, California, to a point more than 100 miles
away. During the past thirty years many individuals and commercial
concerns in different parts of the world have carried on experiments
designed to send signals through the earth; until recently,
though, most of them have been failures or very limited successes.
"But the attention paid to this kind of communication has
increased sharply the last few years. The military is very much
interested in a transmission system buried deep in the earth
and not dependent on vulnerable transmission lines, relay towers,
and so on. Even an atomic attack could not destroy such a system.
Millions of dollars are being spent on underground radio communications
experiments right now."
"How did Space Electronics send the message?" Carl wanted
to know as he pulled the car off the road and parked it beneath
an overhanging limestone cliff.
"The signal from the transmitter went up to the earth's surface
and excited the ground-atmosphere interface. Because of the
discontinuity between the conducting earth and the non-conducting
atmosphere, the waves traveled along this interface in a manner
similar to the way a high frequency travels along the outside
surface of a conductor. When the signal came to a point above
the receiving station, it went down through the earth to the
"Is that the way you think the signal will travel from our
sewer antenna to the cave?"
"No, I'm hoping we may hear the signal through waveguide
action. You see, beneath the earth's topsoil are layers of sedimentary
rock - some wet, some dry. The wet layers act as the boundaries
and the dry layers as the interiors of natural wave guides,
and a radio wave of the proper frequency can go along between
two wet layers just as a u.h.f. signal goes along a metal wave
guide. Right now the soil itself is sopping wet with the rain.
I'm hoping that the soil will form the top and that a wet layer
of sedimentary rock down below will form the bottom of a wave
guide which will lead the signal right into our cave. It'll
be more luck than sense if it does, but we'll never know until
"Okay," Carl said as he got out of the car. "I'll take the
rifle, the gasoline lantern, and the bundle of dowel sticks;
you bring the transceiver and that old field coil from a dynamic
speaker. We want to string up as much antenna as we can, and
there must be half a mile of fine wire on that coil."
The began walking down the steep path that led to the river
and the cave entrance, but they started to slide and ended up
on the rocky ledge bordering the stream amid a small landslide
of loose stones and muddy earth.
"Whew!" Carl exclaimed as he picked himself up and brushed
off his clothing; "that ground is sure soft. It's a good thing
the rain stopped when it did or the road would be sliding down
into the river."
A few minutes later they were back a couple of hundred feet
in the narrow, twisting cave that ran into the limestone bluff.
"Guess we may as well set up shop here," Carl said as he
held the lantern high above his head and looked around. "I've
never gone beyond this point myself, but I think the cave peters
out pretty quickly. You check out the receiver, and I'll string
up some wire for an antenna."
The boys had brought along the transceiver because it contained
the only battery-operated receiver they had. Jerry placed it
on the dry floor of the cave and prepared it for operation.
Carl stuck short pieces of the small dowel stick into crevices
in the cave walls and strung the fine enameled wire stripped
from the speaker field coil on these crude but adequate insulators.
He snapped the end of the wire loose from the spool, and Jerry
scraped off the insulation and fastened it to the antenna post
of the receiver.
They tuned the receiver back and forth across the 75-meter phone
band and the adjacent 80-meter c.w. band with the beat frequency
oscillator turned on, but were unable to hear that first weak
heterodyne even though they knew the band must be busy on a
"Well," Jerry observed, "if we hear anything, it's going
to have to be our own transmitter, which should be turning itself
on about now. Listen hard."
He turned the gain full on so that the cave was filled with
the loud hissing of the sensitive receiver, but not a trace
of a signal could be heard on the 3780-kc. frequency of the
automatic transmitter. They tried putting a ground on the receiver.
They tried shortening the antenna. Finally, they even carried
the receiver to the other end of the antenna and connected it
there. Nothing made any difference. Not a sound, outside of
the heterodyne hiss, could be heard.
"Well, that's that," Jerry said as he glanced at his wrist
watch and shut off the receiver. "The transmitter will cut itself
"It may as well," Carl growled. "All it did was warm the
fish worms with the r.f. Let's take the rifle and -"
He was interrupted by a low rumbling sound that seemed to
come from the distant mouth of the cave. It continued for several
seconds and then stopped.
"Earthquake!" Carl shouted, leaping to his feet and heading
for the cave entrance at a lope. Ordinarily Jerry was not as
quick as Carl, but this time he was right at his chum's heels
when the former sprawled headlong and smashed the lantern he
was carrying. The cave was plunged into darkness.
"Quit walking on me!" Carl said indignantly, pushing Jerry
off him and scrambling to his feet. He took a flashlight from
his pocket and turned it on. The beam revealed a tapering wedge
of mud and loose stones that went from the floor of the cave
all the way up to the roof. In his haste, Carl had slammed into
it. "Wow!" he exclaimed in awe. "An earthslide has covered the
cave entrance. We're in a bind now."
"Yeah," Jerry agreed. He took the flashlight and carefully
inspected the wall of mud still oozing toward them and the sides
of the cave. "I remember that this turn was ten or fifteen feet
inside the cave," he announced; "so we know the wall of earth
is at least that thick. We could never dig through it without
"Someone will find our parked car and start looking for us,
won't they?" Carl asked in a hoarse voice that abruptly squeaked
on the last word he spoke.
"Maybe, but where will they look?
They'll never think of this cave now that the entrance is
covered up. Actually, not too many people know about it anyway.
But let's not hit the panic button. Let's go on back to the
"Lot of good that will do us," Carl muttered as he examined
the shattered mantles of the gasoline lantern. "Strong signals
can't even get into this hole; so our four or five watts have
a fat chance getting out. I'm going to do a little exploring
farther back in the cave. Maybe there's another way out."
Carl went ahead with the flashlight, and Jerry was right
behind him. The walls of the cave narrowed quickly, and soon
the roof dipped down until the boys had to stoop to proceed.
"It ends in a solid wall about ten feet ahead," Carl said
over his shoulder. "Hey, wait a minute!" He scrambled ahead
on his hands and knees and then bent his head back and looked
upward. "Jer!" he exclaimed, "I'm looking right into a sort
of chimney that goes straight up through the rock. It's about
three or four feet across, and I'd guess it was seventy-five
to a hundred feet to the top; but I can see blue sky up there,
and is it ever pretty!"
He backed out and let Jerry crawl into the narrow space to
examine the opening.
"Well, at least we won't suffocate," Jerry concluded as the
boys returned to where they could stand erect.
"Maybe we could build a fire and someone would see the smoke,"
Carl suggested hopefully.
"We could if we had something to burn and if the smoke didn't
smother us before anyone saw it," Jerry discouraged him.
"How about yelling up the chimney?" "Think hard. We've been
up on that bluff above the car. Try to picture where the top
of this opening must be."
Carl nodded glumly. "Yeah, I know; it's right in the middle
of that big briar patch. No one but rabbits would be traipsing
around in there."
He turned off the flashlight to conserve the batteries, and
the two boys sat silent in the pitch darkness.
"If we just had some way of getting a wire outside for an
antenna, we could use the transceiver to get help," Jerry mused.
"How about your throwing a rock with a wire tied to it up through
"Oh, sure! Should I do it lying on my back or toss it up
over my shoulder while I'm on my hands and knees?" Carl asked
sarcastically. "Whitey Ford himself couldn't throw a rock up
to the top of that hole in the position he'd have to take. We
need a trench mortar - Hey! That's it! Turn on the light and
start shaving down one of those dowel sticks with your knife
until it will fit loosely in the barrel of the rifle. Get a
move on. The state traffic net meets in forty-five minutes,
and Chuck, back in town, is net control tonight. If anyone can
hear us, he will."
While Jerry was working down the dowel stick, Carl pried
the lead bullet from a .22 cartridge and sealed the powder in
the case by shoving the sharp edge of the brass case through
a cake of chewing gum. This was inserted in the chamber of Carl's
bolt-action rifle, and the long, slender wooden stick was pushed
down the barrel until the end was resting against the chewing-gum
Next, Carl stripped fine wire from the field coil and carefully
arranged it in a huge spiral directly beneath the vertical opening.
The end of the wire from the center of this flat coil was securely
fastened to the wooden stick at the point where it emerged from
the muzzle. Finally, Carl used loose rock to wedge the rifle
securely against the side of the chimney with its sights aimed
squarely at the center of the blue patch of sky above.
"I guess we're ready," Carl said to Jerry.
"Fire one!" Jerry shouted.
Carl pulled the trigger, and there was a muffled explosion.
The coil of wire disappeared in a blur of motion except for
a dozen or so outside turns.
"That did it!" Carl said joyfully as he peered up the opening.
"We must have had three or four hundred feet of wire in that
coil. Fasten the end to the transceiver and let's see if we
can hear anything."
This took only a minute, and the boys grinned triumphantly
at each other in the yellow glow of the fading flashlight as
Jerry tuned across the crowded 75-meter band and heard signal
after signal coming in loud and clear. He threw the switch to
"Transmit" and checked the transmitter loading; it wasn't too
good, but splicing in some extra wire brought a current loop
to the transmitter terminals and enabled the transmitter to
draw its rated current.
By this time, their friend Chuck was already calling the
roll of net stations. Jerry carefully zeroed on the frequency,
and when Chuck stood by for "any station with traffic," Jerry
broke in with a "QRRR."
Chuck acknowledged him instantly. "How are we coming in?"
Jerry asked. "Like gang busters. What's wrong?" Jerry explained
the situation, and Chuck told him to stand by while he did some
telephoning. In five minutes he was back with the news that
the sheriff and some other men were on their way.
The two boys sat in the darkness and listened to the net
while they waited. It did not seem quite so lonely with the
familiar voices of their ham friends echoing around the cave.
It was only a half hour later that they heard the voice of
the sheriff calling down the shaft. A rope was lowered, and
first Jerry and then Carl was pulled to the top.
When the boys tried to explain what they had been doing in
the cave, the sheriff just shook his head in bewilderment and
said, "Never mind. Just go on home and stay there!"
Minutes later, as Carl drove back along the river road, Jerry
remarked, "Well, I'd not call 'Operation Worm Worming' a great
success, would you?"
"No," Carl said with a shiver, "but I'm not complaining.
For a while there I thought it was going to turn into 'Operation
Worm Feeding,' with us on the menu. What say we leave underground
radio communication experiments to Space Electronics and others?"
"Check!" Jerry solemnly agreed.
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 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
- 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,
Education, July 1963
- 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,
- 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,
Posted January 21, 2015