Citizens Band Research Articles

Personal Use Radio (CB) and Its Effect on TV Reception

The growth in sales of Personal Use Radio, more commonly called Citizens Band Radio, equipment since 1974 has been nothing short of phenomenal. It took 16 years, from 1958 to 1974, to get the first million Class D Citizen Band licensees. At the end of 1975 the figure reached approximately 3.3 million. The Electronic Industries Association predicts there will be more than 20 million CB radios in use in the United States by the end of 1976. The FCC estimates there will be nine million licensed stations at the end of 1976.

Citizen's-band synthesisers

Citizen's-band synthesisers

Breaker, Break, Broke: Citizens Band in the Classroom

Breaker, Break, Broke: Citizens Band in the Classroom

Breaker, Break, Broke: Citizens Band in the Classroom

Breaker, Break, Broke: Citizens Band in the Classroom

A Low Cost Solution to Digital Tuning of Television Receivers and Citizen Band Transceivers

A family of LSI frequency synthesizer circuits and their application to television and Citizen Band Radio are described. With a single crystal as the basic frequency reference, these circuits produce tuning accuracy and long term stability for a large number of frequencies at lower cost than for mechanical or crystal multiplexing methods.

Communications: The explosion at 27 MHz: Citizens band fever in epidemic proportions is straining technology, bandwidth, and the regulators, too

Citizens band fever in epidemic proportions is straining technology, bandwidth, as well as the regulators.

A new single sideband transceiver for the 27 mc Citizens Band service

Extremely rapid growth of the 27 mc Citizens Band service has resulted in extreme congestion of the allocated 23 channels running from 26.965 mc through 27.255 mc. The majority of these 23 channels are spaced 10 kc and to date, standard amplitude modulated techniques have been employed utilizing 5 watts DC input to the plate circuit of the final RF amplifier stage. Transmission of full carrier and both sidebands is normal in this service. Since there is no reason to believe that additional frequencies will be allocated for the Citizens Band service, a better utilization of the allocated channels must come about if any appreciable expansion in the numbers of licensees is to take place over the next few years. The Mark SSB-27 Transceiver described here is capable of transmitting and receiving on either upper sideband or lower sideband with suppressed carrier on any 5 pre-determined channels of the 23 available. This in effect doubles the available number of channels in the Citizens Band service to 46 from the original 23 since tests have proved that the equipment is capable of providing communications for one system on the upper sideband of an allocated channel with simultaneous communication on an additional system utilizing the lower sideband of the same channel when mobile units of the two systems are operating within one mile of each other. Performance of this nature has been attained through the use of standard single sideband suppressed carrier techniques, excellent frequency stability with all frequency determining crystals contained in a temperature controlled oven, and the employment of a high quality 3 kc single sideband crystal lattice filter.

Design features of transistorized citizens band transceivers in Kit form

Interest shown in Citizens Band Equipment has been growing at a phenomenal rate, to put it mildly. There are roughly two classes of equipment allowed by the Federal Communications Commission; those with a power input of 100 MW or less, requiring no license, and the equipment with over 100 MW input to a maximum of 5 Watts input. The latter requires an FCC License as set forth in Part 19 of the FCC Rules and Regulations. Until recently, most hand-held transistorized equipment has been in 100 MW License Free Class, generally restricting useful range to about one mile or less. The price of high frequency Transistors capable of 1 to 2 Watts power input is now economically feasible, making it possible to design Walkie-Talkie Equipment with consistent performance of 2 to 5 miles or more.

The Universal Communications Transistor

The Universal Communications Transistor is a device that can operatie predictably, uniformly and adequately in a wide variety of applications at the most important frequencies for communication service. This device should be priced so that the overall cost of the transistor complement in the particular communication equipment is competitive with the cost of a complement of functionally tested devices. A description of the Post Alloy Diffused Transistor (PADT) technique which results in the device characteristics is given. Closely defined characteristics specifying all the information needed by the designer at the most important frequencies are described. The ability of the transistor and its characterization to define the operation under wide conditions of application, circuit environment and operating conditions is given. A 173-Mc mobile communication transceiver as well as a high quality 100-mw Citizens Band transceiver are also described.

A modular approach to the design of F.M. communication equipment

Through the use of coils wound on subminiature ferrite bobbins, threaded ferrite cup cores and of newly released P.A.D.T. transistors, the T.F. strips of an FM communications receiver have been packaged into two compact, hermetically sealed, pre-tuned components. This ensures built-in optimum performance, reliability and standardisation of an important section of FM receivers for all frequency ranges and simplified maintenance. Similar developments for other sections of FM communications equipment and for Citizen's Band Radio are referred to in this paper.

The citizens band boom

The Citizens Radio Service is defined by the Federal Communications Commission as a radiocommunication service of fixed, land and mobile stations intended for personal or business radio communications, radio signalling, control of remote objects or devices by means of radio, and other purposes not specifically prohibited. Its stated purpose is to provide for the use of radio facilities by any citizen of the United States for private shortdistance radiocommunications, radio signalling, or the control of remote objects or devices by means of radio. The author traces its beginning, its progress, and its present situation, - and makes some predictions on its possible future.

A New Concept in Citizen's Band Equipment

The 27 Mc citizen's radio service was established to provide the public with a short range, personal communication facility. It allows the public to realize benefits similar to those provided commercial users of the business services. Whereas, a station in the latter service is licensed for a specific purpose and frequency, the citizen's service provides the user with 23 frequencies and personal use within the scope of the regulations. The market for this type of equipment is essentially a consumer market with over 100,000 licenses issued and 10,000 applications being received by the FCC every month. As with any consumer product, one of the most important problems of the manufacturer is to provide the purchaser with the utmost in performance and conveniences at the lowest possible cost. Another consideration is ease of operation of the equipment. In particular, consideration should be given to young and old of both sexes in that the unit should be simple to operate.