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The mystery behind an empty television channel

4/13/2021

Joseph Park, Illinois ECE

The radio telescope at the Vermilion River Observatory near Danville, Illinois. Image: University of Illinois
Radio telescope at the University of Illinois
Former Illinois ECE faculty member George Swenson
Former Illinois ECE faculty member George Swenson

A recent article in Vice explores a 20th-century mystery involving former faculty members from Illinois ECE and the groundbreaking radio telescope they built in Central Illinois. The article highlights the mystery as to why Channel 37 was an empty block of static in most parts of the world during the 20th centuiry and how former Illinois ECE faculty member George Swenson's groundbreaking research contributed to that mystery.

Along with British cosmologist George C. McVittie who founded the astronomy department at the University of Illinois, Swenson helped create one of the greatest technological marvels at the time — a 400-foot-wide radio telescope. Managed by researchers from the University of Illinois, the telescope operated 12 to 16 hours a day. 

When the University of Illinois built its radio telescope, the technology behind television was still young and not every television set could access ultra high frequency (UHF) signals. In 1959, the International Telecommunication Union designated a series of important frequencies used for different scientific and technical uses, but Channel 37 occupied one of those frequencies.

Swenson next to the construction of the radio telescope
Swenson next to the construction of a separate parabolic radio telescope

In 1960, the University of Illinois asked the FCC for Channel 37 to be reserved for radio telescopes exclusively. In turn, the FCC refused, stating that it was too early to make a call.

Several years later, more stations were calling the FCC for access to the specific station. The conflict brewed to the point where regulators tried to devise a compromise amongst the parties. In the compromise, no stations were allowed on Channel 37 within a 600-mile radius of the antenna until at least 1968, allowing for McVittie to complete a survey of radio star sources he was doing on the 610 MHz frequency.

Eventually, the FCC agreed to a 10-year moratorium on the use of Channel 37 which eventually became permanent. Ultimately, Channel 37 went unused throughout the analog era in North America as well as most other countries.

 
Read more at Vice.