THE RADIO BOYS
ON THE
MEXICAN BORDER
BY GERALD BRECKENRIDGE
AUTHOR OF
"_The Radio Boys on Secret Service Duty_," "_The Radio
Boys with the Revenue Guards_," "_The Radio Boys'
Search for the Inca's Treasure_," "_The Radio
Boys Rescue the Lost Alaska Expedition_."
[Illustration: FRONTISPIECE]
A.L. BURT COMPANY
Publishers New York
THE RADIO BOYS SERIES
A Series of Stories for Boys of All Ages
By GERALD BRECKENRIDGE
The Radio Boys on the Mexican Border
The Radio Boys on Secret Service Duty
The Radio Boys with the Revenue Guards
The Radio Boys' Search for the Inca's Treasure
The Radio Boys Rescue the Lost Alaska Expedition
By A.L. BURT COMPANY 1922
THE RADIO BOYS ON THE MEXICAN BORDER
Made in "U. S. A."
Table of Contents
FOREWORD
DIRECTIONS FOR INSTALLING AN AMATEUR RADIO RECEIVING TELEPHONE
CHAPTER I - A CRY IN THE AIR
CHAPTER II - THE ENEMY NEAR
CHAPTER III - A DARING LEAP
CHAPTER IV - SHOTS AT THE STATION
CHAPTER V - PLANS FOR THE FLIGHT
CHAPTER VI - A THIEF IN THE NIGHT
CHAPTER VII - KIDNAPPED
CHAPTER VIII - HELD FOR RANSOM
CHAPTER IX - ON THE DESERT TRAIL
CHAPTER X - A BRUSH WITH THE ENEMY
CHAPTER XI - JACK CANNOT SLEEP
CHAPTER XII - JACK DISCOVERS A TRAITOR
CHAPTER XIII - THE NET IS DRAWN TIGHTER
CHAPTER XIV - THE KEY TO THE MYSTERY
CHAPTER XV - TO THE RESCUE
CHAPTER XVI - A SOUND IN THE SKY
CHAPTER XVII - INSIDE THE CAVE
CHAPTER XVIII - THE FIGHT IN THE CAVE
CHAPTER XIX - RESTING UP
CHAPTER XX - CONFERRING BY RADIO
CHAPTER XXI - GAINING AN ALLY
CHAPTER XXII - FLYING TO THE RESCUE
CHAPTER XXIII - THE TABLES TURNED
CHAPTER XXIV - FRANK SAVES THE DAY
CHAPTER XXV - DANGER AT HAND
CHAPTER XXVI - THE NIGHT ATTACK
CHAPTER XXVII - SENORITA RAFAELA
CHAPTER XXVIII - THE FAIR TRAITRESS
CHAPTER XXIX - THREE CHEERS FOR THE RADIO BOYS
CHAPTER XXX - GOOD NEWS FOR ANXIOUS EARS
CHAPTER XXXI - CALM AFTER THE STORM
CHAPTER XXXII - MORE ADVENTURE AHEAD
FOREWORD
The development of radio telephony is still in its infancy at this
time of writing in 1922. And yet it has made strides that were
undreamed of in 1918. Experiments made in that year in Germany, and by
the Italian Government in the Adriatic, enabled the human voice to be
projected by radio some hundreds of miles. Today the broadcasting
stations, from which nightly concerts are sent far and wide across the
land, have tremendous range.
Estimates compiled by the various American companies making and
selling radiophone equipment showed that in March of 1922 there were
more than 700,000 receiving sets installed throughout the country and
that installations were increasing so rapidly it was impossible to
compute the percentage with any degree of accuracy, as the gains even
from week to week were great.
When you boys read this the problems of control of the air will have
been simplified to some extent. Yet at the beginning of 1922 they were
simply chaotic. Then the United States Government of necessity took a
hand. The result will be, eventually, that certain wave lengths will
be set aside for the exclusive use of amateurs, others for commercial
purposes, still others for governmental use, and so on.
In this connection, you will note that in the story Jack Hampton's
father builds sending stations on Long Island and in New Mexico. This
is unusual and requires explanation.
The tremendous growth of amateur receiving stations is due in part to
the fact that such stations require no governmental license. A sending
station, on the other hand, does require a license, and such license
is not granted except upon good reasons being shown. It would be
natural for the government, however, to give Mr. Hampton license to
use a special wave length--such as 1,800 metres--for transoceanic
radio experiments. Extension of the license to the New Mexico plant
would follow.
THE AUTHOR.
DIRECTIONS FOR INSTALLING AN AMATEUR RADIO RECEIVING TELEPHONE
In order that the boy interested in radio telephony may construct his
own receiving set, the Author herein will describe the construction of
a small, cheap set which almost any lad handy at mechanics can build.
Such a set should be sufficiently powerful to permit of successfully
picking up the concerts and other programme entertainments being
broadcasted frequently by stations throughout the country.
Two drawings are given herewith which will enable boys to visualize
the appearance of the set, and will be of aid in following
instructions.
Referring to Figure 1 let us examine first the construction of the
receiving inductance marked L. The latter is shown in detail in Figure
2, and consists of a heavy piece of cardboard. The back of an ordinary
writing pad will do.
[Illustration: Figure 1]
First, draw the circle out with a compass to the diameter shown and
then divide off the outside into an unequal number of divisions as
shown. Draw a light pencil line through each of these marks to the
centre of the circle. Now with your scissors cut out the disc, after
which you cut the slots as shown.
The slots should be about one-quarter of an inch in width and of the
depth shown in the drawing. Two such discs should be made and, when
all cut out, should be given several coats of shellac to add stiffness
and to improve the insulating qualities.
Now at your hardware dealer's buy one-quarter pound of No. 24 double,
cotton-covered wire and proceed to wind the coils in the manner shown.
Keep the windings even and avoid all joints throughout the length of
winding.
When you have finished, mount the coils as shown in the drawing. Make
sure that the windings on both coils run in the same direction. If you
fail to do this, the set will not work.
For the detector, it is better to purchase a good make of galena
detector at any radio supply store. If you are handy with tools,
however, you can buy the galena and make your own detector. It will
work with more or less satisfaction.
Your next need will be the condenser. The condenser consists of a
series of aluminum plates, some of which are movable and the rest
stationary.
Buy a small variable condenser. Its function is to tune the secondary
circuit, which is accomplished simply by turning the knob. Such a
condenser could not be made without the use of a good set of tools,
and the author strongly advises it be bought instead of made at home
in order to avoid trouble. The aluminum plates are spaced very closely
and great care should be taken to avoid bending them, as they must not
touch each other.
The aerial for this set should be about 60 to 100 feet in length and
as high and clear of surrounding objects as possible. A simple
porcelain cleat at either end, as shown in the drawing, will serve to
insulate it sufficiently.
Your ground connection can be made best by wiring to the cold water
pipe, although wiring to a steam or gas pipe will do almost as well.
You are now prepared to mount the various instruments in their proper
locations. For your table instruments, get a good pine board about
seven-eighths of an inch thick. Buy four binding posts and use one for
the aerial wire, one for the ground wire, and two for the phones or
head set.
To operate the set, first bring the hinged coil of wire close up to
the fixed coil and adjust the detector until you can hear in your
receivers the loudest click caused by the turning on and off of the
key to a nearby electric light. If no light is available, a buzzer and
dry battery should be used. When the detector is properly adjusted you
will be able to hear the buzz quite distinctly in the head phones if
the buzzer is not too far away.
[Illustration: Figure 2]
The actual adjustment of the detector is rather a delicate job, and
once it is in the proper position it is a good plan to avoid jarring
it, as it is liable to get out of adjustment very easily.
Once the sensitive spot on your detector is found, slowly turn the
knob on your condenser and at some spot on it you should be able to
pick up signals of some sort, either of radiophone or spark. If the
set does not work, then go over all your wiring and be sure that the
windings of the two coils are both running the same way.
The above set will work well for short distances, say up to twelve or
fifteen miles. Beyond that, however, it will not receive music unless
you have unusual facilities for putting up an aerial to a considerable
height and well clear of surrounding objects.
Such a set should be constructed at a minimum of cost and may later,
after you have become familiar with the operation of radio appliances,
easily be converted into a set of much greater range by the use of a
vacuum tube as detector and may even, by slight changes, be given the
much desired regenerative effects.
CHAPTER I
A CRY IN THE AIR
"Well, Bob, here we are again. And no word from Jack yet."
"That's right, Frank. But the weather has been bad for sending so
great a distance for days. When these spring storms come to an end the
static will lift and well stand a better chance to hear from him."
"Righto, Bob. Then, too, the Hamptons may not have finished their
station on time."
The other shook his head. "No, Jack wrote us they would have
everything installed by the 15th and that we should be on the lookout
for his voice. And when he says he'll do a thing, he generally does
it. It must be the weather. Let's step out again and have a look."
Taking off their headpieces, the two boys opened the door of the
private radiophone station where the above conversation took place and
stepped out to a little platform. It was a mild day late in June, and
the sandy Long Island plain, broken only by a few trees, with the
ocean in the distance, lay smiling before them. A succession of
electrical storms which for days had swept the countryside in rapid
succession apparently had come to an end. The clouds were lifting, and
there was more than a promise of early sunlight to brighten the
Saturday holiday.
The boys looked hopefully at each other.
"Looks better than it has for days, Frank."
"That's right."
A few moments more they chatted hopefully about the prospects, then
re-entered the station.
Frank Merrick and Bob Temple were chums, a little under 18 years of
age each. It was their bitterest regret that they had been too young
to take any part in the World War some years before. Frank was dark,
curly-haired, of medium height and slim, but strong and wiry. Bob was
fair and sleepy-eyed, a fraction under six feet tall and weighed 180
pounds. A third chum and the leader of the trio was Jack Hampton, 19
years of age. He had gone to New Mexico several months before with his
father, a mining engineer.
All three boys were sons of wealthy parents, with country estates near
the far end of Long Island. Frank's parents, in fact, were dead, and
he lived with the Temples. Mr. Temple was his guardian and
administrator of the large fortune left by his father, who had been
Mr. Temple's partner in an exporting firm with headquarters in New
York City. Jack Hampton also was motherless.
The boys were keenly interested in scientific inventions, and were
given every facility by Mr. Temple and Mr. Hampton for indulging their
hobbies. Such indulgence required considerable sums of money, but the
men believed the boys were worth it. In fact, both gentlemen were
scientifically inclined themselves, and were able to give the boys
much valuable advice.
When Mr. Hampton decided to go to Texas and New Mexico as the
representative of a group of "independent" oil operators engaged in a
bitter war with the Oil Trust known as the "Octopus," Jack begged so
hard to be permitted to go along that his father let him quit
Harrington Hall Military Academy two months before the end of the
term.
It was agreed that when school ended, June 28, Frank and Bob should
join Jack in the Southwest for their summer vacation. The two boys
owned an airplane in which they hoped to make the trip when the time
came. Mr. Temple, however, was dubious about letting them attempt to
make so long a flight alone.
"But, Dad," Bob would argue, whenever the matter was discussed, "we'll
be all right. We've made lots of flights without any accidents. We're
as capable as anybody. You know yourself what the instructors up at
Mineola told you. You say we are too young to fly away alone. But look
at the young fellows that got to be 'aces' in the War! Not much older
than we are now."
It must be confessed that Mrs. Temple thought little of the matter one
way or the other. She had so many social duties to take up her time
that there was little left for the boys. Accordingly, the boys had
only Mr. Temple to persuade and they felt pretty certain of doing that
in time. So the last two months of school were spent in poring over
maps and routes, and in studying up on landing fields and flying
conditions generally throughout the territory they would have to
cover.
Much of this study for the proposed flight was carried on at the
radiophone station on the Hampton estate. Mr. Hampton was an
enthusiast about the development of radio telephony and it was through
him the boys first had become interested in the subject. A year
earlier he had built a powerful station for the purpose of making
experiments in talking across the ocean. On that account the United
States Government had granted him a special permit to use an 1,800
metre wave length.
Before leaving for the Southwest, Jack told the boys his father
intended to build in Texas or New Mexico another radiophone station of
similar wave length. This would enable Mr. Hampton to communicate
with his New York confreres through his Long Island station. The big
thing to the boys, however, was that they would be able to talk to
each other across 2,000 miles of territory. Delays in construction in
the Southwest had occurred, however, and communication between the two
stations had not yet been established when our story opens.
As the boys re-entered the station after their inspection of the
weather, Bob threw himself sprawlingly into a deep wicker chair and,
picking up a book, began idly to turn the pages. Frank went to the
table where the control apparatus was located and put on a headpiece.
For a few moments there was silence, which Frank presently shattered
with a loud cry of: "Bob. Bob. Come here."
Bob dropped his book and, leaping to his feet, strode to his chum's
side.
"What is it?"
"Put on a headpiece, Bob," said Frank in a voice of great excitement.
"I believe Jack is trying to get us."
Excited as his chum, Bob clamped a receiver on his head, while Frank
manipulated the "amplifier" and "detector" knobs on the control
apparatus.
A variety of sounds greeted the boys at first, whistles, calls, and
chattering coming to their ears. Then as their tuner searched out the
higher regions of the air, they shut out the sounds of the low-range
air traffic. There was a thin, shrieking sound. Then, that also
disappeared. And then quite suddenly the listening, expectant boys
heard Jack's voice speaking to them just as plainly as if he stood in
the room.
"Frank. Bob. Bob. Frank," Jack was saying. "Can you hear me? Can you
hear me?"
"Hurray, Jack, sure we can hear you," cried Frank, bending forward to
speak into the transmitter on the stand before him.
Then as Jack's voice continued calling without paying him any
attention, he straightened up and laughed.
"Gee. I forgot," he laughed. Laying down his headpiece, he ran across
the room; opened a door into the power house adjoining where the
mechanic was dozing over his pipe and called to him to throw on the
generator.
Galloping back, as the man obeyed, Frank again snatched up his
headpiece. Bob already was bending over a transmitter, calling to Jack
in faraway New Mexico. Both boys listened with straining ears for the
response. Presently Jack answered: "I can hear you, but only very
faintly. Put that band piece on the talking machine. You know the one
I like so much. I can't think of its name. I'll tune to it."
Frank hastily shuffled through a pile of talking machine records.
Finding the one he sought, he put it on the machine which stood
directly in front of a big condensing horn strapped to the back of a
chair to give it the proper height. A moment or two later, Jack's
voice in the receivers declared:
"All right. Shut her off now. I'm fixed fine."
"Say, Jack, think of talking 2,000 miles like this," said Bob.
"Oh, we've been working some days out here," answered Jack. "But we
couldn't get you."
"No," cut in Frank. "The static interfered, I guess. But it lifted
today."
"How are things going, Jack?" Bob inquired next.
Jack's voice became excited. "Going?" he answered. "Fellows, I never
knew what excitement was until this last week."
"What do you mean?" demanded both boys together.
"Oh, I couldn't tell you now," laughed Jack. "It would take all day
and then some to tell you all that's happening around here. But, let
me tell you, between Dad's business opponents and a gang of Mexican
bandits that appeared on the scene lately, things are getting pretty
lively. Say, when are you coming? Now's the time if ever----"
Suddenly, Jack's voice ceased abruptly, to be succeeded a moment later
by his agonized cry for "Help." Then there was a crash that rang in
the eardrums of the alarmed boys listening in. Then, silence.
"Jack. Jack," they called. "What's the matter?"
There was no answer.