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This chapter focuses on the performance of materials and equipment used in radio installations. Several kinds of radio and electronic equipment are constructed of many different materials, each of which might suffer deterioration in different ways. The physical properties of plastics depend more on environmental operating temperature than those of metals. The variety of plastic materials and detailed accurate information available about them are such that the designer can choose a material for a certain application with a high degree of certainty that he would be able to obtain such characteristics. Plastic covered cables buried in the ground are soon damaged by termites and brown ants where these insects are prevalent. High claims are made on performance and life of modern contacts but environmental conditions can introduce many problems. Impurities in the air can cause a lot of troubles. Then there are chemical combinations that produce thin films on the contact surfaces. These films have to be cracked by the contact pressure and removed by the sliding motion of the contacts. Silver is also used in radio equipment because of its high conductivity but silver migration can be a problem in environments of high humidity. In certain conditions, the use of silver leads to the development of low insulation resistance or even complete breakdown of an insulating gap.

Publisher Summary This chapter discusses the importance of proper management during radio installations by an organization. Many radio installations have suffered heavy fire losses throughout the world because management have not developed their fire protection arrangements sufficiently enough to match technical advances that have been taking place with their radio equipment. In larger organizations with high capital investment, management must ensure the appointment of responsible people in the organization to coordinate and supervise an effective fire prevention and protection program. Management has a responsibility to ensure that there is sufficient staff adequately instructed and supported to effectively control and extinguish the types of fires, which could reasonably be expected within the technical plant and buildings under their control. Management must be willing to consult with and accept recommendations from various authorities and organizations that have the technical knowledge and expertise.

This chapter focuses on the budgets and costing aspect of radio engineering projects. Budgeting is a means of planning so that the best possible use might be made of all available resources in achieving certain defined objectives. It is an integral part of forward engineering planning and provides the means for measuring the efficiency with which these plans are put into operation. In monetary terms, the budget establishes an objective of performance; having been established with sufficient detail, it serves as a guide, as time elapses, against which to check actual performance and in turn to keep the performance on program. As a general rule, budgets for the provision or maintenance of the radio engineering facilities pass through three stages of development, namely, preparation of needs or initial overall requirements, preparation of the coordinated realistic requirements, and preparation of the coordinated realistic requirements. Costing involves finding the cost of undertaking separate classes of work such as erection and maintenance of masts, installation and maintenance of radio equipment, power plant or finding out the cost of undertaking separate types of work.

Publisher Summary This chapter focuses on the protection of radio equipment. All radio equipment should be provided with protective circuits. There are two main reasons for providing protection, namely, to prevent a component or equipment assembly reaching a temperature that might result in fire and to minimize the hazards to staff in the event of an unsafe condition developing. Radio equipment that would require maintenance work upon it should have approved means of disconnecting it from all unearthed conductors of its supply circuit. Care must be taken in the design of the control circuit or mechanism that power cannot be restored while work is in progress. To provide adequate protection for staff, equipment, and plant against lightning, it is necessary to install facilities by which a discharge is not required to pass through a path of high impedance. The station property should also be enclosed by a fence of proper height and construction that would prevent access to the property by unauthorized persons and grazing animals.

Publisher Summary This chapter focuses on the factors that can affect radio transmitting equipment. Radio equipment is working in all parts of the world, in outer space and in all types of environments. In practice, no single condition, such as humidity, vibration, shock, low or high temperature, and high altitude is present by itself, but is in combination with one or more others. The reliability of equipment is also influenced by the standard of design and workmanship, the quality control exercised during manufacture and assembly, the quality of materials and the finishes used in the equipment. High humidity conditions result in the moisture being deposited on surfaces and can be injurious to materials and equipment. The absorption of moisture is one of the chief causes of the deterioration of materials exposed to humid conditions. Radio stations located in certain city areas might be subjected to an atmosphere that is contaminated with industrial fumes, which might be corrosive to antenna systems, masts, towers, and equipment. Radio construction projects can be disrupted during these storm periods, particularly during work associated with the construction and erection of foundations and steel-work of masts and towers.

Publisher Summary This chapter discusses the radiation hazards that are associated with many modern broadcasting, radio communication, and radar transmitters. The large effective radiated powers used in many radio stations have raised the problem of personal safety for staff working on or near these installations. Radiation hazards might exist at any radio frequency that is capable of being absorbed by the body. An examination of the electromagnetic spectrum indicates that the main classifications of radiation are radio frequency (RF) waves, infra-red or heat waves, the visible spectrum, and ionizing radiation, including ultra-violet and X-rays. Radio equipment that produces this type of radiation includes low frequency radio telegraphy, broadcasting, radio communication, television, and radar systems. Industrial equipment such as that used for diathermy, induction heating, microwave ovens, and dielectric heating, also use this portion of the spectrum. The degree of injury from electromagnetic radiation to living tissue depends on the absorbed energy within that tissue that varies with the power density, duration of exposure, type of modulation, and frequency of the source. The potential hazards that might arise from exposure to RF radiation fields are believed to be because of, either directly or indirectly, increases in body temperature resulting from the absorption of the electromagnetic energy.

This chapter focuses on the electrical and radio equipment used in radio stations and how to operate them effectively without any hazards. The electrostatic discharges experienced by staff working near unshielded high voltage equipment, such as transmitter tank circuits, and high power antenna matching networks, do not as a general rule constitute a direct hazard but they might lead to accidents of a secondary nature. Proper earthing of radio and electrical equipment is important when working with high voltages. Conductors and equipment properly earthed can be a life saver, but when earthed through the body of a workman can be fatal. The earthing wand or stick attached to transmitters and other equipment using capacitors connected to high voltages should be fitted with an auxiliary testing probe wired in series with a suitable current limiting resistor. Batteries systems at large radio station complexes might be extensive. Battery rooms should be provided with adequate ventilation, particularly during charging, to exhaust gases and to minimize explosions.

This chapter discusses the hazards that are associated with electric shocks in radio equipment. Putting out fires near live radio equipment is likely to be dangerous and might result in severe shock. The shock might be caused by the extinguishing agent acting as a conductor and passing a current through the fire fighter. It might also be caused by direct contact with live equipment or flashover to a conducting hose nozzle or similar metallic device. Some radio stations are provided with water spray systems, which provide a cooling effect through the high rate of evaporation of water into steam. The application of the spray might result in an immediate drop in the design factor of safety and the situation could lead to a violent flashover. The arc could also spread to the fire fighter's hose nozzle. Extinguishers of the carbon dioxide type produce a discharge containing carbon dioxide vapor and solid particles of dry ice, or carbon dioxide. The substance is a good electrical insulator and might be considered to be non-conducting for practical purposes.