June 1963 Popular Electronics
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
While a bit far-fetched,
this Carl & Jerry saga from the June 1963 issue of Popular Electronics
magazine has the two amateur radio hobbyists cum detectives applying their knowledge
of standing waves and an invention called
SNARE, "Signal Net for Actuating Radio-sensitive Explosives," by Irwin Ehlmann,
to thwart an assassination attempt on a visiting foreign dignitary. The name of
the patent is actually "Method and apparatus for
detonating radio frequency sensitive blasting caps," but the principal is the
same. The choice by author John T. Frye of a halo antenna on their mobile shortwave
rig was probably no coincidence given the guardian angel role it played in the adventure.
Carl & Jerry: Elementary Induction
" ... see if you don't make out a pair of wires going down over
the edge of the bluff ... "
By John T. Frye W9EGV
A Carl and Jerry Adventure in Electronics
The dew-washed June morning found Carl and Jerry testing out their super-duper
Field Day radio station atop a high limestone bluff overlooking the river. Radio
amateurs, on their annual Field Day, familiarize themselves with the operation of
emergency radio equipment by competing to see which station can make the most contacts
during a 24-hour period. The score made is multiplied substantially if the station
is set up out in the "field" with no connection to commercial power lines.
Determined to run up a high score, the boys had two five-hundred-watt transmitters
in the back of a station wagon borrowed from Carl's parents. One was a band-switching
job that could be operated on all amateur bands from 75 through 10 meters. The other
transmitter was for six meters only.
An all-band trap antenna had been swung between two trees for use with the band-switching
rig. On Field Day, there would be a rotatable beam for the six-meter station, but
today the boys intended to test the station out with a halo-type antenna mounted
on the rear bumper of the station wagon.
A two-wheel trailer containing a husky 10-kw. gasoline-powered a.c. generator
was hitched to the rear bumper of the station wagon. It was puttering away while
Jerry hunkered down inside the station wagon connecting antennas, mikes, switches,
relays, etc. Carl was outside playing around with a powerful, tripod-mounted, prism-type
spotting telescope he had recently acquired.
Carl looked back along the steep, narrow, twisting dirt path up which the station
wagon had clawed its way from the paved road running alongside the river down below.
Then he raised the front of the telescope and looked across the river at the road
running along the top of the bluff on that side.
"Hey, wonder why the law is so busy across the river," he called to Jerry. "I
can see the sheriff's car and two state police cars cruising along over there."
"Didn't you look at last night's paper?" Jerry asked. "The president of a South
American country is going to inspect a typical Midwest corn farm about two miles
west of here on the other side of the river at ten this morning. It's feared political
enemies from his country may try to kill him and so create an international incident.
Naturally, our government intends to do everything possible to prevent anything
of this nature. That's undoubtedly why the police are checking the route so carefully."
"So that's it," Carl muttered, swinging the telescope to the right and peering
through a thin screen of bushes at the top of another limestone ridge a half-mile
away on his side of the river. "Boy, this 'scope is really a honey," he remarked.
"There are a couple of guys sitting over there on that other ridge, and I can see
the buttons on their shirts. Wonder what they're doing. They seem to be just sitting
there with a kind of funny-looking gasoline can between them. One of them keeps
watching the road across the river through a pair of binoculars."
To Carl and Jerry Fans:
I'd like to answer personally all the wonderful cards, letters, and messages
wishing me a quick recovery from my recent illness; but, as I'm sure you understand,
that is virtually impossible; so I'm taking this means to thank all of you who sent
The good wishes and prayers mentioned in so many of these heart-warming messages
must certainly have "worked," for I have recovered completely.
Writing future Carl and Jerry stories will be even more fun now that I know so
many of you readers enjoy them. Thanks a million!
John T. Frye
Note: This greeting was published in response to a notice of Mr. Frye's illness
that appeared in the
February 1963 edition of Popular Electronics.
Jerry slid out the back of the station wagon and came over for a look. "That's
no gasoline can," he exclaimed; "it's a blasting-cap detonator! Look closely and
see if you don't make out a pair of wires going from it down over the edge of the
bluff to the road below and then across the road through some treetops and on down
toward the river."
"Yeah," Carl agreed, "and those wires keep right on going across the river and
up the bluff to that little culvert under the road over there. So help me: those
jokers must be planning on blowing up the president when he crosses the culvert!
We better go tell the police."
"There's no time," Jerry objected, looking at his watch. "The president's car
should be along any minute now, and there isn't a farmhouse either way for two miles.
By the time we got to a telephone it would be too late. I'm going to try to raise
someone on seventy-five meters and have them call the police!"
The boys scrambled into the station wagon and fired up the bandswitching transmitter.
Jerry pushed the button on the mike while he watched the meters on the front of
the transmitter. A worried frown creased his forehead as he quickly rechecked the
"Something's wrong," Jerry said.
"We're getting no drive to the final." Gingerly he raised the lid of the exciter
and peered inside. "The driver tube is stone cold," he announced, "and we don't
have a spare. The filament must have been jarred in two by the rough ride up here."
"Try the six-meter rig," Carl suggested, glancing nervously across at the empty
highway on the other side of the river.
Jerry quickly put the high-frequency transmitter into operation and desperately
called "QRRR," the amateur emergency distress signal. No sign of an answer was heard
in the receiver.
Twice more he put out the distress call, with absolutely no results. "It's no
use," he said as he snapped off the receiver and started unscrewing the coax cable
antenna lead from the other transmitter. "No one monitors six meters around here
this time of day. Our only chance is to get down there to where the wires cross
the road and try to break them before the president comes along.
"You drive," he suggested hurriedly as he threw the end of the cable out the
rear of the car, "and don't spare the horses."
"Hadn't we better uncouple the generator?" Carl asked as he climbed into the
"No time for that; get going!" Jerry urged.
The drive up that steep zigzagging path had been spine-tingling, but it was nothing
compared to the ride down. Carl sent the station wagon hurtling along the narrow,
twisting path while behind, the heavy generator, still humming away, bumped and
jolted and careened first over on one wheel and then on the other, threatening to
overturn at any instant. Somehow, though, they finally reached the black-topped
road that paralleled the river.
Just as Carl made a tire-screeching right turn onto the road, Jerry glanced up
at the top of the bluff directly across the river and uttered an exclamation.
"There's the motorcade now," he shouted. "See if you can gain a good lead on
them before we reach the wires."
Carl tried. The accelerator was clear to the floor as the station wagon and the
heavy trailer raced along the winding black-topped road, but the cavalcade across
the river was also traveling at a fast clip on a stretch of highway that ran perfectly
straight. As the station wagon neared the point where the wires should run across
the road, it was obvious to both boys the scant 200-yard lead they had over the
state police car leading the motorcade was not enough to give them time to locate
the detonating wires, stop the car, get to a point where they could reach the wires,
and cut them.
Carl kept taking quick upward glances as he let the car slow down. "There they
are!" he said, pointing to where two inconspicuous wires crossed the road from one
treetop to another. A glance was all that was needed to convince the boys that the
wires were far too high to be reached even if they stood on top of the station wagon.
"Stop the car with the back bumper directly under the wires," Jerry called to
Carl slammed on the brakes, and the wagon came to a lurching stop with the halo
antenna squarely underneath the twin strands of wire. Jerry threw full power into
the six-meter transmitter, and he and Carl stared in sickening fascination at the
rapidly closing gap between the motorcade and the mined culvert across the river.
Suddenly there was a muffled roar, and a fountain of dust and broken pieces of
concrete erupted from the point where the highway crossed the culvert. As the rocks
and chunks of concrete rained down into the river, causing splashes that reached
almost halfway across, the boys saw the entire cavalcade brake to a halt a scant
hundred yards from where the explosive had torn a gaping trench clear across the
The boys leaped from their car and looked upward at the point where the wires
disappeared over the top of the bluff above. Two dark-skinned faces silhouetted
against the blue sky stared down at the boys and at a car parked at the side of
the road not far away from the station wagon. After a few frozen seconds, the faces
"That must be their getaway car," Carl exclaimed. "They probably will be afraid
to try to get to it now with us here, but just to make sure we'd better take the
rotor out of their distributor. They must really feel pretty sick about getting
impatient and blowing up the culvert too soon."
"They didn't blow up the culvert; we did," Jerry corrected him.
"We what? You must have had your little gray cells jarred by that explosion.
How could we have set off the dynamite, or whatever it was ?"
"We did it with r.f. from our six-meter transmitter. Radio frequency currents
from the halo antenna induced similar currents in the wires leading to the dynamite
caps. Standing waves on these wires produced heating in the caps and detonated them."
"So that's why you wanted "me to stop with the back of the car directly under
the wires! What ever made you think of detonating the caps with r.f.?"
"Well, we both know it's dangerous to use transmitting equipment in an area where
blasting is going on. We've seen highway signs warning against that sort of thing.
And then I was reading a story recently about a patent that had been taken out to
eliminate explosions on airplanes caused by bombs concealed in baggage. The apparatus
is called SNARE, or Signal Net for Actuating Radio-sensitive Explosives. A man by
the name of Irwin Ehlmann of Hatboro, Pennsylvania, is the inventor.
"The device consists of a 30-foot bombproof chamber with a conveyor belt running
through it. Baggage on this belt is exposed to strong radio frequency waves of different
wavelengths. These radio frequency waves will detonate any caps concealed in the
baggage and so set off the explosive.
"When I realized we couldn't reach the wires in time, all this flashed through
my mind. There wasn't anything else we could do; so it seemed worth a try-"
Jerry was interrupted by a wailing siren, and in a few seconds a state police
car came to a stop behind the generator which was still sitting in the middle of
the road. The police across the river had seen the wires leading across the water,
and they had dispatched a cruiser to investigate. The officer, "Doc" Watson, was
known to the boys, and they quickly explained to him what had happened. He relayed
the information over his radio, and a net was quickly thrown up around the area.
"Those fellows will be picked up shortly," officer Watson prophesied. "They don't
stand a ghost of a chance of getting away on foot.
"We all certainly owe you two a big debt of gratitude," he said then, "but I
must admit I still can't understand how you set off that dynamite clear across the
river without even touching the wires."
"Elementary induction, my dear Dr. Watson, elementary induction!" Carl replied
with a teasing grin.
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.
Vox Electronik, September 1958
- Pi in
the Sky and Big Twist, February 1964
Bell Bull Session, December 1961
Boogie, August 1958
- TV Picture,
Electronic Eraser, August 1962
Trap, March 1956
at Work, June 1956
Aweigh, July 1956
Bosco Has His Day, August 1956
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
Santa's Little Helpers - December 1955
Two Tough Customers - June 1960
Pocket Radio, TV Receivers
Yagi Antennas, May 1955
Stomping, March 1962
Blubber Banisher, July 1959
- The Sparkling
Light, May 1962
Research Rewarded, June 1962
- A Hot Idea, March
- The Hot
Dog Case, December 1954
A New Company is Launched, October 1956
Under the Mistletoe, December 1958
Electronic 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
Elementary Induction, June 1963
- He Went
Electronic Detective, February 1958
Aiding 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 August 20, 2021(original