VHF VERSUS UHF TELEVISION

by

R. J.. Reiman, Historian

VHF TV stations on the air surged from about 100 in 1950 to over 500 in 1988. The UHF broadcasters, however, were in a long and costly struggle. The propagation characteristics of UHF were not as favorable for broadcasting as for VHF, since UHF is attenuated more rapidly by terrain by its shorter wavelength. The smaller UHF receiving antenna were less effective than their VHF counterpart and UHF sections of TV receivers were less sensitive as well. Lastly, the UHF sets were more expensive and the programs offered by the UHF stations were not sufficiently interesting to overcome the other limitations. During these years of growth, network programs were not available to the UHF'ers and being an "independent" was not too popular.

The number of UHF stations of 100 in 1950 did not get to be 200 until 1980. In 1975, the increase in availability of popular programs, the all-channels receiver law, FCC regulatory actions, the effect of cable television and technical progress all led to profitability and growth.

As the result of increased demand for programming by TV broadcasters, an industry developed to produce and distribute TV programs. Over 800 companies including 20 news services were formed in response to this demand. The total revenues which were $324 million in 1952 grew to more than $21 billion by 1986. The demand for TV advertising exceeded the capacity of VHF to handle it. In 1963, the FCC amended the Communications Act to require all TV sets to be able to receive both VHF and UHF channels. Improvement in the sets came gradually, helped by tighter restrictions on specifications, especially in the area of tuning.

In order to further promote UHF, the FCC increased the maximum permitted power and antenna height for UHF stations. The power limit was raised from 200KW to 5,000KW, and the antenna height from 500 feet to 2,000 feet. VHF antenna height was also raised to 2,000 feet. These changes gave UHF some degree of equality to VHF. In spite of all changes, VHF still has a significant advantage in uniform signal strength over UHF, and UHF experienced another competitor to profitability in cable TV. Recording video on magnetic tape, and color TV both led to increases in broadcasting revenues.

Meanwhile, another contest was begun, that between the transmission of TV programs, especially intercity, by cable or by microwave. The contest would challenge AT&T's monopoly over these capabilities and eventually lead to deregulation of AT&T's monopoly.