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?"
"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 next door.
"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 earth?"
"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 receiver."
"Is that the way you think the signal will travel from our sewer antenna to the
"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 bound-aries 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 we try."
"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 Saturday afternoon.
"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 off now."
"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 tools."
"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 transceiver."
"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
"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 that hole?"
"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 wadding.
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
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
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
"Check!" Jerry solemnly agreed.
Carl Anderson and Jerry Bishop were two teenage boys whose
love of electronics, Ham radio, and all things technical afforded them ample opportunities
to satisfy their own curiosities, assist law enforcement and neighbors with solving
problems, and impressing – and sometimes toying with - friends based on their proclivity
for serious undertakings as well as fun.
Electrical Shock - September 1955
- A Low Blow - March 1961
- The Black
Beast - May 1960
Electronik, September 1958
- Pi in
the Sky and Big Twist, February 1964
Bell Bull Session, December 1961
Boogie, August 1958
- TV Picture,
Eraser, August 1962
Trap, March 1956
at Work, June 1956
Aweigh, July 1956
Has His Day, August 1956
- The Hand
of Selene, November 1960
or Not?, October 1956
Electronic Beach Buggy, September 1956
Extra Sensory Perception, December 1956
in a Chimney, January 1956
Performance, November 1958
of Judas, July 1961
- The Sucker,
New Year, January 1963
Snow Machine, December 1960
Extracurricular Education, July 1963
Slow Motion for Quick Action, April 1963
Sleuthing, August 1963
- TV Antennas,
a Soroban, March 1963
Fair --", September 1963
Worm Warming, May 1961
Operation Startled Starling - January 1955
Light Subject - November 1954
Teaches Boy - February 1959
- Too Lucky
- August 1961
and Jeopardy - December 1963
Santa's Little Helpers - December 1955
Tough Customers - June 1960
Pocket Radio, TV Receivers
Yagi Antennas, May 1955
Stomping, March 1962
- The Blubber
Banisher, July 1959
- The Sparkling
Light, May 1962
Research Rewarded, June 1962
- A Hot Idea, March
- The Hot Dog
Case, December 1954
New Company is Launched, October 1956
the Mistletoe, December 1958
Eraser, August 1962
- "BBI", May 1959
Sound Waves, July 1955
- The River
Sniffer, July 1962
- Ham Radio,
Torero Electronico, April 1960
Wireless, January 1962
Electronic Shadow, September 1957
Induction, June 1963
- He Went
Detective, February 1958
an Instinct, December 1962
- Two Detectors,
with a Tachometer, July 1960
and the Pirates, April 1961
The Crazy Clock Caper, October 1960
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."
Posted February 10, 2022
(updated from original post on 1/21/2015)