March 1945 QST
Wax nostalgic about and learn from the history of early electronics. See articles
QST, published December 1915 - present. All copyrights hereby acknowledged.
It's hard to imagine a time when unlicensed radio
frequency bands were not the norm, but early in the history of radio, strict spectrum
control was necessary in order to prevent unintentional radiation from crappy equipment interfering with services. Remember that even in the mid 1940s, many, if not most,
casual users were cobbling together their own transmitters and receivers from scratch.
Transmitter powers were easily high enough to interfere with nearby and distant receivers,
but even improperly shielded receiver oscillator ("exciters") could cause interference
with a neighbor's nightly Lone Ranger broadcast.
Around 1945, the FCC began entertaining the idea of allocating bandwidth for the use
of the newfangled "walkie-talkies" that were developed for field communications during
World War II. This 460 to 470 MHz band was the first of the Citizens' Bands that eventually
opened up in the 27 MHz realm, which was widely adopted by the trucking industry in the
1970s. Cellphones are the latest step in the evolution of license-free radio devices,
occupying bands in the 800, 900, 1800, 1900, and 2100 MHz bands.
The Citizens Radiocommunication Service
Commission Proposes Walkie-Talkies for General Citizenry
Outside of the amateur allocations, the most
interesting feature to us in the Federal Communication Commission's report on its proposed
postwar allocations above 25 Mc. was its announcement of its intention to create a new
Citizens Radiocommunication Service for the use of the general public under minimum licensing
We comment on this topic on this month's editorial page and our purpose here is simply
to present the Commission's own language from its report, which tells the tale very well
The development of light-weight portable short-range radio communications equipment
of the "walkie-talkie" type has opened the door to a large variety of new private applications
of radio. The success of such communications on the battlefront has been followed by
many suggestions for peacetime use of low-power portable transceivers in the cities,
on the highways, and in rural areas. To make possible the fullest practicable development
of private radio communications within the limits set by other demands for assignments
in the spectrum, the Commission on its own motion proposes to allocate the band from
460 to 470 Mc. to a new "Citizens Radio-communication Service."
The possible uses of this service are as broad as the imagination of the public and
the ingenuity of equipment manufacturers can devise. The citizens radiocommunications
band can be used, for example, to establish a "physicians" calling service, through which
a central physicians' exchange in each city can reach doctors while they are en route
in their cars or otherwise not available by telephone. Department stores, dairies, laundries
and other business organizations can use this service in communicating to and from their
delivery vehicles. Similarly, it can be used in communicating to and from the trucks,
tractors, and other mobile units operating in and around large industrial plants and
construction projects - many of which spread over a number of square miles. It can be
used on farms and ranches for communications to and from men in the fields; on board
harbor and river craft; in mountain and swamp areas, etc. Sportsmen and explorers can
use it to maintain contact with camps and to decrease the hazards of hunting, fishing,
boating, and mountain climbing. Citizens generally will benefit from the convenience
of this service by utilizing two-way portable radio equipment for short-range private
service between points where regular communication facilities are not available. During
emergencies when wire facilities are disrupted as a result of hurricane, flood, earthquake,
or other disaster, the service, as has been demonstrated by the amateur service, will
be of inestimable value.
Separate allocations are being made for urban and for rural transit radio communications,
which will be available for communicating with city or intercity buses, trucks, taxicabs,
etc. These services may develop on a common carrier or private basis on the frequencies
set aside for those purposes. In either event, the citizens radio communication band
will be open to taxicabs, delivery vehicles, or other mobile units, as well - as for
incidental communication between fixed points.
Common carrier operation in the Citizens Radiocommunication band will not be permitted,
and no charge can be made for the transmission of messages or use of the licensed facilities.
The service will thus be for the private use of the licensee who will be responsible
for the use of the facilities under the regulations to be promulgated- by the Commission.
The 460-470-Mc. band which the Commission proposes to allocate for this service is
essentially adapted to short-range communications, and as such, is admirably suited to
the uses proposed.. The rules will permit the use of "booster" or automatic relay installations
where necessary. It is anticipated that most transmitters on this bandwidth be of low
power and will not utilize extreme antenna heights. Higher power may be permitted in
rural areas where no interference will result.
"The design of equipment for use in the citizens radio communication band should challenge
the ingenuity of radio designers and engineers. A combination transmitter and receiver
of reasonable weight can no doubt be mounted in a suitcase; a broadcast receiver, an
alarm system, remote control systems, and other devices can perhaps be added to meet
particular needs. By keeping the rules and regulations to a minimum, the Commission hopes
to encourage ingenuity in design and in utilization.
As in the case of the amateur service, the Commission proposes to assign no channels
within the band. It is reasonable to suppose that most equipment will utilize a channel
of 150 kc. more or less, making possible some 60 or 70 channels; but, as in the amateur
band, these matters will not be determined. by rule or regulation. It should be possible
by the use of comparatively simple circuits already known to provide both transmitters
and receivers tunable over all or most of the 460-470-Mc. range and emitting signals
sharp enough to minimize interference.
The bands both above and below 460-470 Mc. are assigned to other services; but the
allocation is such that if the utility and requirements of citizens radiocommunications
warrant, the band can at some future time be expanded. Alternatively, if a demand for
assignments in this band does not arise, the band can be reassigned to another service
at a later date .
The essence of this new service is that it will be widely available. Accordingly,
only the minimum requirements of the Communications Act plus a few minimum traffic rules
will be set up. Operator licenses will be granted only to citizens of the United States.,
To procure such a license, an applicant need only show familiarity with the relevant
portions of the Communications Act and of the simple regulations governing this service.
No technical knowledge will be required. It is hoped that the license can be in the form
of a small card, with the operator's license on one side and the station license on the
other, and that these will remain in force for five years with simple renewal provisions.
Station licenses will be limited to point-to-point, fixed point-to-mobile, mobile-to-mobile,
and multiple-address communications; broadcasting is not contemplated.
A concomitant of the widest possible availability is that particular licensees are
not accorded protection from interference. A license in this service does not guarantee
the right to a channel; it affords rather an opportunity to share with others the use
of a band. The success of this arrangement in the amateur bands gives every reason to
believe that it will be equally successful in the citizens radio communications band.
In the event that intolerable abuses arise, the Commission will of course take steps
to eliminate them. The 10,000 kc. width of the band will no doubt be sufficient, however,
to make possible simultaneous and efficient use of the limited-range service for many
purposes, with serious interference limited to few if any parts of the country.
In any areas where serious interference is experienced, it is the expectation of
the Commission that various users of the band in a particular community will jointly
seek, perhaps through local organizations similar to the American Radio Relay League
in the amateur field, cooperatively to solve local problems of interference and to
ensure maximum utilization. The new service is essentially a local service; the
problems will differ widely in an urban and rural area, in the mountainous West and
the flat Middle West, etc. The Commission is prepared to cooperate with local groups
which may be formed in the working out of cooperative arrangements and it will resort
to limiting regulations only in the event that an imperative need is shown.
Posted November 27, 2018 (Original August 1, 2011)