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The Road To UHF

by K.M. Richards

While it's difficult to fathom from the perspective of the 21st Century, there was a time when all television was on the VHF band. In fact, there weren't even officially designated channels until 1937 and even before UHF came along some fifteen years later the number and frequencies of VHF channels changed several times.

EMPHASIS ON STANDARDIZATION: The first attempt at standardization of television broadcasting in the U.S. came on October 18, 1937, when FCC Order 19 allocated eighteen channels for television operation; five were in the approximate frequency range of today's channels 2 through 6; two in what is now the FM radio band; six where channels 7 through 13 are assigned now, and six more just above channel 13. There were no standards for television transmission yet -- that would take more than three additional years of discussion -- and the FCC was hesitant to move forward until a standard had been adopted.

Nevertheless, on February 28, 1940, the Commission authorized limited commercial television operation, to take effect that September, making clear that they were doing so "to the extent that stations engaged in regular telecasting will be enabled to obtain from sponsors sufficient revenue to defray operating overhead." The order stressed avoiding "emphasis on the commercial aspects at the expense of program research." They put off the establishment of standards for another year.

Almost immediately, RCA (then the corporate parent of NBC) began an intensive merchandising and sales campaign for television receivers in New York City, designed to receive what was then a 441-line picture with lower-fidelity AM sound. (At the time, DuMont had been developing a higher-resolution 625-line system.) That caused the FCC to rescind the February action on March 23, and to publicly censure RCA for violating its intent, emphasizing that nothing in the authorization allowed activities that would "encourage a large public investment in receivers which, by reason of technical advances, may become obsolete in a relatively short time." The Commission made it clear that they felt RCA had violated that provision with its newspaper and trade-paper promotion, along with price cuts in existing receiver models. The FCC reopened the hearings on the subject on April 8, and RCA attempted to defend its actions, but by the following month the FCC had returned to its previous position of waiting until standards could be adopted before opening up television reception to the masses.

On May 27, the FCC formally returned television to experimental status "until engineering opinion can agree on transmission standards" by completely scrapping the rules it had adopted in February. RCA had no comment. At the same time, they began to discuss the possibility of reallocating the frequency range then used by channel 1 to the new FM radio service, which would have affected NBC's New York station, as well as early stations in Chicago and Los Angeles.

The first seven commercial television channels,
from the NTSC standards adopted by the FCC in 1941.

COMMERCIAL TELEVISION AUTHORIZATION ... AND THEN A SCREECHING HALT: It took less than a year for progress to be made. On April 30, 1941 the FCC adopted new rules adopting standards developed by the National Television System Committee, based on a 1936 recommendation made by the Radio Manufacturers Association and calling for a 525-line picture (called a "compromise" between the NBC and Dumont systems) and FM sound. The Commission authorized commercial operation on channels 1 through 7 -- the remaining 11 channels to be available for experimental operation using NTSC or other systems -- with a minimum weekly operating schedule of 15 hours per week. The first two television licenses for regular commercial operation were issued June 17, 1941 to NBC (whose experimental W2XBS became WNBT) and CBS (whose W2XAB on channel 2 became WCBW). In order to prevent either from gaining the advantage of being "first" the licenses took effect simultaneously, at 1:00pm on July 1 (however, WCBW did not manage to begin operation until 2:30, so what is today's WNBC-TV inadvertently holds the distinction as the oldest continuously operating commercial television station in the United States). DuMont's W2XWV on channel 4 kept its experimental authorization.

In the months that followed, both NBC and CBS applied for additional stations in other cities, as did other companies such as Westinghouse which planned to become active in television. However, World War II had an unplanned effect on the expansion of television, and upon the recommendation of the Defense Communication Board in April, 1942 the FCC "completely and unequivocably" halted the issuance of new radio and television station construction permits (an earlier "quasi-freeze" had been in effect since February 12, 1942 but had given the Commission discretionary power to license stations in areas that were not receiving adequate service), although previously issued permits were allowed to be built and the FCC routinely granted CP extensions "in view of circumstances beyond the permittee's control" until after the war. There were no further new construction permits issued without the applicant specifying in advance the availability of transmitting equipment until April 10, 1946.

On May 2, 1944 DuMont's experimental W2XWV was converted to commercial operation as WABD.

UHF BEGINS TO ATTRACT ATTENTION, IN COLOR, NO LESS: With much of its usual business thus curtailed, the FCC decided to begin looking at how to allocate frequencies after the war. Where television was concerned, this led to a 1945 proposal reducing the number of television channels -- all VHF -- to 12 coupled with a statement that television would "eventually" be moved to the 480 to 920 MHz band (which is almost precisely where channels 14 to 83 ended up). To that end, the proposed allocation of the UHF frequencies was made for experimental television "in order that a television broadcast system may be developed for the transmission of color pictures and superior monochrome pictures through the use of wider channels."

The 13 VHF channels proposed in 1945. This also reflected the FCC's decision
to move FM from its original allocated band of 42-50 MHz to 88-106 MHz.

By year's end, however, there was a new proposal on the table calling for 13 channels -- the additional channel added below channel 7 -- with channels 1, 12 and 13 used for low-power "community" stations and the remaining ten assigned to metropolitan areas with wider coverage. Under attack from industry opposition, this was eventually cut back to a single community allocation (channel 1 in most cases) which would have been the only station in 15 of the 140 metropolitan districts that were to be assigned channels.

As part of the frequency changes, WABD was moved to channel 5, as that more closely matched its former channel 4 frequency; WNBT was moved to the new channel 4 so as to be on a "metropolitan" channel.

Test pattern for the CBS color television transmission
system, which nearly became the standard.

CBS saw an opportunity when it read the language reserving the UHF band for experiments in color television, as their Peter Goldmark had been working on the idea since 1939, with test broadcasts beginning the following year. Goldmark's "field sequential" system rivaled Technicolor film for accuracy of color reproduction, but carried a significant drawback; to describe it simply, it transmitted three screens of information -- or frames -- for each displayed image, one for each of three color components (red, green and blue) and a "color wheel" in the receiver, synchronized with the one at the originating end, colorized each frame as it was received. With a fast enough frame transmission rate -- and CBS transmitted twice as many frames per second as were used for monochrome transmission -- the human eye merged the individual color screens into a single full-color image in the brain. Not only did the "color wheel" seem a clunky addition to the all-electronic television transmission system standardized in 1941, the CBS system was incompatible with NTSC monochrome reception.

In September, 1946 CBS petitioned the FCC to adopt its system, which by then had evolved to a system using a 16 MHz wide channel. The following month, RCA -- which had also experimented with a mechanically-based color transmission system in 1941 and found it lacking -- proposed its own "simultaneous" color system, which was entirely electronic. However, it also used a channel more than twice as wide (14.5 MHz) as existing broadcasts used.

The FCC held hearings from December, 1946 through February, 1947 on color television, the highlight of which was a demonstration of the CBS system on January 27 and 28. At the end of it all, the Commission denied the CBS petition moving all television to UHF using its system as "premature", issuing a report on March 18, 1947 saying that CBS' system "was not adequately field tested and other narrowband systems were not explored" and that both systems required too much spectrum space. (Specifically, the FCC noted that using the 16 MHz channel CBS proposed would permit only 27 channels in the UHF band, which it felt would be insufficient for a nationwide competitive television system.) Two years later, the FCC formally requested industry proposals for color transmission systems using the existing 6 MHz channel width.

To make this portion of a long story shorter, RCA re-engineered its system into a "dot-compatible" system and CBS tinkered with its color wheel to make it fit into the existing channel width. After a disastrous demonstration of the RCA system on October 10, 1949, followed by comparative demonstrations on November 21 and 22 of that year, the FCC approved the CBS system on October 11, 1950 with the provision that new television sets would be required to support both CBS color and NTSC monochrome. RCA sued six weeks later, the Supreme Court upheld the decision seven months after that, and the first "official" CBS colorcast took place on June 25, 1951, but there was so little public acceptance -- only 400 color sets were manufactured and by some accounts only one-quarter of those were sold, at a cost of $499.95 each -- that CBS ended color telecasts on October 20. The NTSC was called back into session and recommended standards based on the RCA system, which was approved December 17, 1953; ironically, it was CBS, not NBC, which aired the first color program using the new compatible standard, at 6:15 that evening, using a converter that took the field sequential output of their existing color equipment and transmitted it in NTSC. Thus ended UHF's role in the development of color television.

(For the complete history of color television's development, the reader is directed to Ed Reitan's site on the subject. See external links, below.)

UHF GETS SERIOUS CONSIDERATION: The decision on color television standards was not the only matter before the FCC in the 1940s. Facing increasing complaints of interference to television broadcasting by the shared use of the frequencies for channels 1 through 6 by fixed and mobile radio services, an engineering conference was called in June, 1947 to discuss the problem, as well as interference on channel 2 from amateur radio operation and adjacent-channel FM interference. The conference ended up also receiving proposals for additional television channels (DuMont proposed ten be added just above the FM band, Zenith proposed moving everything into the UHF band) but mobile service equipment manufacturer Motorola was insistent that "television must be prepared to give up at least one of its first six channels" if peace was to be established. One FCC engineer proposed a radical, but logical solution ... the allocation of 15 consecutive channels, starting at where channel 7 already was, to replace the "split band" channel frequency assignments. Other Commission engineers proposed combining channels 1 and 2, reordering the low-VHF band and removing ham radio operation from that band (which drew an expected protest from the head of the American Radio Relay League). One suggestion to save spectrum space while still affording interference protection was to create a table of overlapping channels, still 6 MHz wide but spaced 4 MHz apart; the proponent suggested it would work by assigning alternating geographic areas all-odd and all-even channels! In the end, it was Motorola's proposal to assign channel 1 to non-television use which the Commission was asked to consider ... and formally proposed on August 14 of that year.

By that time, with the war having ended and the Commission processing new station applications, it had become obvious that there was going to be greater demand for television than the 1945 channel allocations table was designed for. So in conjunction with amending the table of channel assignments to replace channel 1 in the metropolitan areas it had been assigned to in 1945 (12 communities, plus revisions in four other areas to accommodate the replacement channels) the FCC announced its intent to provide more assignments to smaller communities, which resulted in a new table being proposed on May 6, 1948 containing 955 assignments in 459 communities on the 12 remaining VHF channels.

However, having already said in 1947 that 27 channels was an insufficient number when rejecting the original CBS color system, it was finding the 12 remaining VHF channels were obviously not going to do the job either. So a freeze on the new construction of television stations was approved, effective September 30, 1948, while a near-complete overhaul of the assigment table was undertaken; in the meantime which all pending applications were suspended, along with hearings on applications and decisions on cases already heard. FCC Chairman Wayne Coy made it clear that more space would be provided for television on the UHF band but that he did not know "if it can be done now or not." 303 television applications were pending, 37 stations were on the air, and 86 construction permits were outstanding at the time (the holders were allowed to continue construction), and it was estimated that the freeze would last "six months to a year" while changes were worked out.

It actually took 3½ years: After an ad hoc engineering conference was held that November, a new notice of proposed rulemaking was released July 11, 1949 to use all 12 existing VHF channels and 42 UHF channels for a revised channel assignment table. Hearings began in September, with a second set of hearings a year later after the color standards decision was "made" in October, 1950; those hearings resulted in a notice of further rulemaking being issued March 21, 1951 increasing the number of UHF channels to 52 and reserving channels for non-commercial educational use.

And you may ask yourself "well ... how did I get here?"

The FCC partially lifted the freeze that July, authorizing temporary increases in power for existing stations, and the now-famous Sixth Report and Order officially lifting the 1948 freeze was issued April 11, 1952. All 70 UHF channels were included, resulting in 2,002 assignments (569 VHF and 1,433 UHF) in 1,274 cities. The "post freeze" rules became effective June 2, 1952 and the FCC began processing applications July 1.

The first UHF grants were made July 11, 1952 for the stations which would become WICC-TV/43 Bridgeport CT, WKNB-TV/30 New Britain CT, WHYN-TV/55 and WWLP/61 Springfield MA, WFMJ-TV/21 and WKBN-TV/27 Youngstown OH, KPTV/27 Portland OR, and WNOW-TV/49 York PA, as well as for the unbuilt KDEN/26 Denver CO, WNBH-TV/28 New Bedford MA, WCTV/28 Flint MI, and KCTV/18 Austin TX. The next four grants, on July 24, were for non-commercial educational stations in New York State, only two of which -- WMHT/17 Schenectady and WXXI-TV/21 Rochester -- made it on the air (they are still operating today).

And that is how we poor unsuspecting viewers got UHF.


  • Wikipedia page showing frequencies used for American television, pre- and post-1948
  • Ed Reitan's Color Television History
  • Broadcasting special section of the April 14, 1952 issue on the lifting of the freeze, including the new channel allocation table and extensive summary of comments received during rulemaking

Site concept © Clarke Ingram. Site design by K.M. Richards.