[Table of Contents]People old and young enjoy waxing nostalgic about
and learning some of the history of early electronics. Popular Electronics was published from October 1954 through April
1985. As time permits, I will be glad to scan articles for you. All copyrights (if any) are hereby acknowledged.
equipment installed in the trunk of the car takes up relatively little space, is out of the way." That sentence
seems really strange in today's world of pocket-size mobile phones, but it was a big (literally) deal in 1957. If
you are getting old (but not old yet) like me, you'll remember the prime time TV show called
, where crafty private eye Joe
Mannix had a "futuristic" Motorola car phone in his convertible. Today, the only kind of radio you are likely to
find installed in a car trunk is a high-power Ham rig. Two-way messaging was a big deal before the advent of
cellphones. Service trucks were dispatched by operators at the home base. As an electrician back in the 1970s,
most of the trucks I operated from had a two-way radio for directing workers to job sites. I did a lot of
troubleshooting and old work (adding circuits and equipment to existing establishments, as opposed to new
construction work), so I typically went to numerous job locations each day.
See all articles from
Radio Keeps You in Touch
By Leo G. Sands and Mike Bienstock
and telephone systems use radio waves to keep pace with today's business world
You're a doctor. You're out on a call this evening, and it's a half-hour drive to your patient. When you
get there and call in, your nurse tells you one of your patients has had a serious accident. He's in the hospital
now, and they're operating.
You're a doctor. You're out on a call this evening, and it's a half-hour drive
to your patient. Suddenly the phone under the dash rings once. You pull over, pick up the handset, press the
button, and you are in instant contact with your office. Your nurse tells you one of your patients has had a
serious accident. You speed to the hospital where you are in time to supervise the operation.
sound nice, but a bit futuristic? You're partly right. It is nice, but communication with a moving car is here
today, a bustling youngster growing lustily and with practically an unlimited future. The prospects are
tremendous, not only for the doctor who receives emergency calls, but for anyone whose business requires him to
keep in constant touch with home base ... salesmen, who may get tips on customers ... executives whose advice may
be needed to make a critical decision ... newspapermen, who may be routed to cover a top story while it's
happening ... radio and television servicemen who may be sent on an emergency. The list is nearly endless.
There are a wide variety of services available. Let's examine them in order of cost and complexity.
One-Way Radio Paging
. Not quite the same as the Dick Tracy wrist radios, these receivers are pocket-size
jobs which weigh a few ounces. They can be rented or bought at a cost of about $50. The subscriber to this private
service takes the tiny radio out of his pocket, holds it to his ear, presses a button and listens. The names or
call numbers for those with messages waiting are transmitted from a base station. Generally the information is
taped and rebroadcast until the subscriber calls in, then the signal is erased.
The little lady is shown demonstrating one-way radio paging. Subscriber presses button and hears the taped
To extend this service over a greater range, a mobile receiver with a built-in speaker can be mounted under the
dash. Since a superheterodyne circuit is used, the range is stepped up. The car battery furnishes the power to
operate the set.
Telephone companies provide a similar auto signaling service. The signal is a buzzer and
light. Installation for such service is half of the regular auto radio-to-telephone service - $25 for most areas,
plus $12.50 for rental and maintenance, plus a minimum calling charge of $5 which would pay for 30 to 40 calls.
. This is handled by private communications firms. The installation includes
equipment similar to that used in regular mobile radiotelephone, which will be described under that category. The
service differs in this way: instead of direct voice contact between both parties, the message is shorts topped by
a third person, the company operator.
Suppose the doctor's nurse wants to call him. She rings up the
private operator and gives her the message she wants delivered. Then the operator calls the doctor on the road. He
gets the signal, picks up his mike or handset, and answers her. She gives him the nurse's message. Direct
communication, of course, would be in violation of the common carrier tariff filed by the telephone company.
Typical charges in the New York area are as follows: a monthly fee of $36.30 allows 100 air-minute
messages, after which you are charged 10 cents per call. Incoming messages are billed at a straight 10 cents each.
The fee is broken down to $17.50 monthly for service, $10.50 for rental and $5 for maintenance. There is a 10%
Federal tax. Installation charge is $25 per unit, and removal charge is $10 payable in advance.
Citizens Radio Service
Mobile telephone transmitter and receiver control panels at Pacific Telephone & Telegraph Co.
Mobile telephone equipment installed in the trunk of the car takes up relatively little space, is out of the
Message service control center is operated by two persons, one taking telephone messages, the other on radio.
(Anti-science people like a certain country's president would lament the replacement of these types of jobs with
automated computerized equipment, similar to
ATMs stealing tellers' jobs
Car is equipped with a two-way Bendix mobile unit provided by message service common carrier.
A typical mobile telephone is installed in the car below. Note handset holder and control unit under dash.
RCA installation of a two-way mobile radio system at a large trucking firm.
. There are three types in this category: Class A, B and C stations. We are
concerned with only the first two, since Class C is strictly for remote control transmission.
stations may only be operated on 465 mc., with a maximum input power of 10 watts. Class A may be operated on any
frequency in the 460 to 470 mc. band, with power limited to 10 watts between 462 and 468 mc. and 50 watts on the
The further distinction between the two is that equipment cost for Class A transmission
pretty well limits its use to commercial firms interested in getting distance, which is usually eight to ten
miles, depending on terrain and conditions. Class B, therefore, is generally used by private citizens who get a
range of one-and-a-half to six miles, depending on conditions. Vocaline makes transceivers for this band which
sell for $139.50 a pair. They require no installation.
For a Class A installation, initial cost may run to about $700 for the car equipment and $1200 for the base
station, which can be at home or in the office. It may cost more if a tall antenna support is needed at the base
and if a heavy-duty generator is necessary in the car. The equipment will give a range of eight to ten miles in
most areas even without elaborate antenna systems at the base. The higher the base antenna, of course, the greater
the range. Reflection characteristics of u.h.f. make it possible to enjoy good communication in shielded areas
such as streets lined with tal1 buildings.
The car antenna is a small vertical whip about 6" long, mounted
on the car roof. The radio equipment is usually mounted in the trunk and is housed in a single metal case which
includes the transmitter, receiver and power supply. A loudspeaker, hand microphone and a small control unit are
mounted on or near the dash.
The base station transmitter, receiver and power supply are generally
enclosed in a desk-mounted cabinet. It is only necessary to plug it into the closest outlet and connect to an
With such a Citizens Radio setup, operation is very similar to police or taxi operations.
Since it operates on u.h.f, there is little or no noise. No special skill is needed to work it. It is already
pre-tuned to your frequency. In the car there are only three controls: an "on-off" switch, a volume control, and a
squelch control which eliminates background noise.
When you hear your office call, you pick up the
microphone, press the button on it and talk. When you are through, you release the button to hear the incoming
message. The base station operation is similar except that a desk-type microphone is generally used. Telephone
handsets may be used in place of microphones.
Specific frequencies are not assigned in Citizens Radio. You can order your equipment for any frequency in
the band. If you find that someone else's system interferes with yours, you may have your frequency changed.
No operator's license is required. To get your station license, fill out and mail FCC Form 555 to the nearest FCC
field office or to the FCC in Washington. Your equipment must meet FCC approval. Mobile Telephone
. Just as the name implies, this means a telephone in your car. Similar to ship-to-shore
radio-telephone, the system is operated by the local telephone company and makes a phone booth of your car. Under
the dash there is a control unit with signals to light when power is on, a bell and a hand phone which fits into a
hanger on the unit. When you are called, the bell rings, a "call" light goes on and you pick up the handset, press
the button in it and talk - just as simply as if you picked up your home phone. The latest addition is a
"dial-direct" system by Du Mont, which allows direct dialing in the local phone network.
In the trunk of
the car, there is a v.h.f. transmitter, receiver, power supply and dialing decoder. A short antenna is mounted on
the car roof, and sometimes an oversize generator is furnished to take the added load from the battery.
picking up the handset and pressing the push-to-talk button, the driver can signal the phone exchange. When the
operator answers, he gives the number of the phone he wants to reach, identifies his own unit by number, and the
call is placed. Calls to mobile units can be placed from any telephone or from similar mobile installations.
To sum up, this system is essentially the same as an ordinary phone installation, with radio being used in place
of phone wires. Generally the phone company has one transmitter in the headquarters building, with several
receiving stations at strategic locations. Transmitting and receiving stations are connected by telephone lines to
the central office.
The range of the system is generally confined to the 15 to 25 mile radius of the
transmitter. The service is on a "party line" basis, with several subscribers using the same channel. Charges for
such service - in a large area of the country (including such cities as New York, Cleveland, Chicago,
Philadelphia, Los Angeles and Dallas) are $50 for initial equipment installation and $32 monthly. The monthly cost
includes maintenance as well as a minimum charge which pays for 15 to 20 calls. Additional calls cost 30 cents or
more, depending on distance and length of conversation. Other Services
. There are, of
course, other services. These, however, will only be mentioned, since they ordinarily are not available to the
private individual. Private Two-Way Radio, Licensed, includes police, taxis, railroads, bus lines, utilities and
pipeline companies who have for years used their own mobile sets. Amateur Radio Mobile Service is ordinary amateur
radio moved into the air. An operator's license is needed, which limits the latter service to relatively few
people. Note that while Citizens Radio is open to any citizen for private or commercial use, Amateur Radio Mobile
Service is strictly limited to personal use with no profit motive.
Dispatcher is shown in communication with
one of the local pickup and delivery trucks.