Long before there was Power
is the free equivalent), presentations at training seminars were conducted using
overhead projectors and larger-than-life props of the devices being taught. The
U.S. Navy, during World War II, set up a special facility called the Visual
Aid Model Shop located at
Radio Chicago, Chicago, Illinois. Its charter was to design and
build very large scale models of equipment and tools that service personnel used
while performing their duties. It is kind of funny to look at the sizes of some
of the items, like the 8x size radio chassis assembly shown in this article's main
photograph. As a life-long model builder myself, I would have loved to work in a shop like
that building torso-size electrolytic capacitors and potentiometer bodies as large
as dinner plates. The closest I ever got to it professionally was while working
at Westinghouse Oceanic Division (now Northrop Grumman) in Annapolis, Maryland,
as a technician building prototype electronics and mechanical products. One of the
bummers of earning my BSEE degree was having to relegate that kind of work to techs
because my employers thought they were paying me too much to do it myself.
Training with Visual Aids
Miss Hazel Fox, civilian employee of Ship's Service at Radio
Chicago, holds normal sized receiver for comparison with the giant instructional
model made by Visual Aids Department.
Instructional techniques used by the Navy to train their radio and radar repairmen
can be used by civilian schools.
Radio Chicago, the primary school of the U. S. Navy's Radio Technician Training
Program, is doing a big and important job in the training of men to repair and maintain
radar equipment, radio direction finders, u.h.f. equipment, and other such devices.
When these men complete their radio technician training less than one year after
entering the program, they are radio and radar technicians qualified to keep many
types of the Navy's electronic equipment operating at top efficiency.
The thoroughness of the Navy training is, in itself, almost as great a scientific
wonder as the marvelous equipment with which the students work. To assemble a conglomeration
of men of all ages and backgrounds, possessing varying degrees of aptitude and general
knowledge, put them through schooling comparable to some collegiate science courses,
and within a year bring them to a mutual level of ability as highly skilled technicians
in a field as abstractly theoretical as electronics, indeed requires a scientific
approach. If anyone method of instruction can claim credit for the rapid development
of these potential radio technicians, that method would be the extensive visual
aid program which is a vital adjunct to the teaching techniques used at these radio
The training given radio technicians deals only with material associated with
the theory and practice of radio and radar maintenance. This fact alone streamlines
and differentiates the course from college engineering curricula, and the use of
visual aids in presenting theory and practice to the student has been found to be
of invaluable assistance in the transmission of new knowledge.
Lt. (j.g.) A. L. Rogers. W9OZE, Visual Aids Officer of Radio
Chicago, holds a normal sized coil for comparison with the instructional coil made
by visual aids.
Over-all view of the Visual Aid Model Shop located at Radio Chicago,
Chicago, Illinois. In this shop are built all of the visual aids used to teach radio
The principles of using the slide rule are taught by means of
a quant model while students make computations on their individual rules. Chief
Radio Technician E. J. Tripler of Montrose, Colorado. is instructing the class on
the small slide rule while the model on the wall is being set by Charles Barrett,
Specialist (X) 3/C, of Deland, Florida, a member of the Visual Aids Department for
Laboratory where students are building five-tube superheterodynes
as one of their projects before graduation. Note the large scale model of the receiver
mounted on the wall for the guidance of the students in placing parts.
The results which have been achieved by means of visual aids in the field of
adult education have aroused the interest of educators throughout the country.
The Radio Technician Training Program, as it is set up today, involves several
educational helps which are of interest to the layman and educator alike. The first
step in the program requires that the applicant for radio technician training successfully
pass the special aptitude test which is designed to select only those best qualified
and most likely to complete the prescribed course. This pre-selection of the students
is accomplished by means of the well-known "Eddy Test". This test which was devised
and developed by Captain William C. Eddy is not a measure of man's technical or
mechanical, background, but it does preclude a better-than-average working knowledge
of high school mathematics and physics. While these two subjects receive the primary
emphasis in the examination, it is also necessary for the applicant to understand
certain phases of general science, shop practice, elementary electricity, and radio.
The "Eddy Test" is roughly divided into five categories covering approximately
80 questions on mathematics, physics, shop practice, electricity, and radio. In
the field of mathematics, it is necessary for the applicant to be able to perform
simple mathematical operations such as cancellations, division, multiplication,
addition of algebraic fractions, square roots, percentages, equations and logarithms,
etc. The part of the test covering physics requires a working knowledge of heat,
light, magnetism, sound, and other phases of general science. Shop practice covers
the use of various tools including micrometers, hand tools, the reading of shop
drawings, the correct use of files, screws, bolts. soldering irons, etc. The requirements
for electricity and radio cover Ohm's Law, direct current circuits, elements of
alternating current theory, basic receiver principles, vacuum tubes, and circuit
The test breaks down into 40% mathematics, 20% basic physics, 15% basic electricity,
15% basic radio, and 10% shop practice. The grades received by the students in these
tests are entered as part of their Navy record and these records have resulted in
a careful study of case histories and several revisions in the "Eddy Test", but
basically the test remains about the same as it was at the time of its adoption
in the early part of 1942.
Upon the successful completion of the "Eddy Test" and providing the candidate
meets all of the physical and other requirements of the Navy, the student is sent
to "boot" training where he must first of all become a sailor before he becomes
a specialist. In boot training the student learns how to sling a hammock, how to
tell port from starboard, and, in general, become a sailor. During this period,
which lasts from five to twelve weeks, he can talk radio and dream radar to his
heart's content but nary a radio tube or textbook does the candidate see.
Upon completion of "boot" training, the candidate enters pre-radio school, where
during a month's course of intensive study he reviews high school algebra, learns
the elements of electricity and the fundamentals of shop practices by means of lectures
and laboratory classwork. In this school the student is first introduced to the
visual aid "method of instruction.
The use of the slide rule is taught by means of a giant nine-foot model of its
familiar counterpart. This model is constructed to scale and is capable of being
operated by the instructor. Problems worked by means of the slide rule are illustrated
by the instructor, who makes the proper setting on the large scale model and the
class then performs the proper operation on their individual rules.
In a similar manner, recognition of tools and the proper use of various shop
equipment is taught. Sharpening of bits and twist drills becomes easier for the
student because giant models of the grinding operation and cutting surfaces of the
tools are available for comparison.
Thus, when the student completes his work at the pre-radio school, he is already
familiar with many of the visual aids which he will meet time and again in primary
and secondary schools.
In the Primary schools, the student begins his work on radio equipment and associated
test equipment in earnest. Each student, before his graduation from the primary
school, is required to construct a complete five-tube superheterodyne receiver.
The proper placement of parts and the general layout of the chassis are taught by
means of a giant receiver which is exactly scaled to the original. The theory of
radio operation is also taught by means of this gigantic receiver, which is large
enough for a six-foot man to move around in comfortably.
In the courses in shop practice, the correct use of soldering irons, micrometers,
and hand tools are continued at a high level by means of large scale models of each
of these instruments. In specific instances, the use of visual aids has cut the
training time in almost unbelievable amounts. In one experiment involving the installation
of an octal tube socket in a chassis and the soldering of wire leads from a resistor
network to certain socket prongs, fifty-five minutes were lopped off the instruction
time by the use of a visual aid. Before the adoption of this instruction technique,
it was the practice of the instructor to lecture to the students for a one-hour
period on the correct practices involved in performing this operation. By means
of the oversized model constructed by the Visual Aids Department, the lecture time
was cut to a five minute preliminary outlining of the problem to be done.
Jack Phillips, Specialist (X) 1/C of Long Island, New York, demonstrates
the large sized micrometer used for instructional purposes. The normal sized unit
is shown for comparison.
The Du Mont twenty-inch oscilloscope is being used by Chief Ernest
Sindelar. Chief Instructor of Radio Chicago, to instruct Charles O. Whitehead, Radio
Technician 2/C, of Columbus, Mississippi, on correct operating procedure.
In similarly dramatic fashion, the operation of the oscilloscope and correct
interpretation of patterns on its screen is taught to the students by means. of
a 20" oscilloscope which is easily visible to the entire class during the instructor's
lecture-demonstration. Since most of the features of the more readily portable units
are incorporated on this demonstration 'scope, the class is thoroughly familiar
with the operation of all the controls when he begins work on the oscilloscope projects.
The testing of meters, which has always been considered an extremely difficult
subject to teach to groups because of the small size of most meter parts, has been
facilitated by means of model meters which are built eight times normal size. Every
detail down to the last coil turn is duplicated faithfully by the model makers.
In addition to individual pieces of equipment, the student becomes familiar with
several other types of visual aids during his course of study. Circuits of various
pieces of equipment are "blown up" and built onto a demonstration board. In some
working models the operation of a receiver may be demonstrated and the signal traced
through the circuit by means of electrically operated indicating devices. Various
types of tubes, both receiving and transmitting become familiar to the student because
actual tubes are mounted on demonstration panels for his inspection. In addition
to this familiarization process, the Visual Aids Department builds giant stripped-down
models of the internal construction of the tube showing all working parts, without
the glass envelope in place.
Students are taught correct procedures for maintaining and servicing
soldering irons from this giant model being supported by Francis Mair, Specialist
(X) 1/C of Streatorville, Illinois, Mr. Mair is the head of the Visual Aids Department
of Radio Chicago.
Great care goes into the construction of each unit turned out by the visual aids
group so that every feature of the model closely resembles or duplicates the characteristics
of the original, including solder joints, etc.
The great majority of the visual aids in use at Radio Chicago have been the handiwork
of the Visual Aids Department connected with the school. From a small beginning
in November of 1942, when the first artist was assigned to the school, this department
has expanded until today it is a full-fledged organization working full-time on
the job of preparing training aids for the Navy.
The pioneer artist, upon whom rested the responsibility of organizing the work,
was Chief Specialist (X) Brander, who is now a lieutenant stationed at the Bureau
of Personnel, Training Division, in Washington, D.C. By January, 1943, this department
had grown to three staff artists and model makers who devoted their entire time
to producing training aids for the rapidly expanding radio school. Today this department
keeps twelve Navy men busy full-time preparing the various material for classroom
instruction. A completely equipped workshop permits independent operation of the
department. Many types of materials are used in the construction of the models,
including plastics, wood, plywood, sheet steel, and non-priority material. The work
of this department is now under the direction of Lt. (j.g.) A. L. Rogers, a peace-time
radio amateur from Waukegan, Illinois.
In addition to the models used for training, the Navy is also a staunch champion
of the efficacy of motion pictures and slide films in training operations. A Training
Aids Library was set up at 1212 North Lake Shore Drive, Chicago, for the purpose
of supplying films and projectors to supplement the visual aids.
By Navy contract, Burton Holmes Films, Inc. produced a 16 mm. sound movie in
the laboratories of Radio Chicago entitled "Radio Technician Shop Practice". Upon
completion of this standard 40 minute film, 3 more 16 mm. sound films and about
20 slide films (35 mm.) were produced in a similar manner under the supervision
of Navy instructors at Radio Chicago.
Thus in several different forms, the Navy is making use of various time-saving
visual aids in the instruction of their radio technicians.
It seems certain that in the postwar era, schools and colleges will be quick
to take advantage of what the Navy has learned laboriously. When students from all
walks of life are brought together to learn the intricacies of any science or abstract
subject, new and disassociated ideas must be presented to them in a simplified,
easily grasped manner if utmost speed of instruction and intelligent comprehension
is to be obtained.
Visual aids have proved to be the ideal medium to achieve this end, for it is
this method that has enabled Radio Chicago to prepare untrained naval personnel
for the exacting task of maintaining the complex electronic equipment which is the
voice, eyes, and ears of the U. S. Navy.
Posted July 25, 2022
(updated from original post on 3/3/2015)