The Y Files

In 1948, the U.S. Federal Communications Commission (FCC) stopped granting new television licenses. Buried beneath a mountain of applications and wondering, perhaps, which applicants were secretly "un-American", federal regulators froze the television landscape for four years. At the time, only 24 American cities had two or more TV stations. Smaller ones didn't have any at all. Even mid-sized markets such as Denver, Colorado and Austin, Texas went unserved.

Defrosting the Freeze of 1948

The Freeze of '48 did more than deprive TV viewers of their chance to watch Pantomime Quiz, a popular game show that won an Emmy in 1949. At a time when less than 2% of Americans owned television sets, Westinghouse Electric Corporation was forced to limit many of its television technology experiments. One of the experiments that survived was a patented technology called Stratovision, a precursor to satellite communications.

The brainchild of Westinghouse engineer Charles Noble, Stratovision solved the line-of-sight problem that limited TV broadcasters to ground-based transmitters and ground-based receivers. Charles Noble's idea was to equip airplanes with broadcast equipment so that TV signals could be transmitted to a wider audience. While flying at 25,000 ft., a plane could cover a radius of 225 miles – twenty times more than a ground transmitter.

Testing Stratovision

From June 1948 to February 1949, Westinghouse conducted two phases of Stratovision tests. During the first phase, a twin-engine PV-2 aircraft transmitted with 250 W on 197.5 MHz and 5 kW on 514 MHz. The signals, broadcast above Baltimore, were then recorded at Norfolk, Virginia and Pittsburgh, Pennsylvania. The second phase of testing traded the PV-2 for a modified B-29 Superfortress flying at 30,000 ft.

Equipped to relay transmissions from WMAR-TV in Baltimore, the B-29 received its originating signals from circular dipoles attached to a mast atop the aircraft's vertical tail fin. The retractable broadcasting antenna that hung vertically beneath the aircraft featured a two-element turnstile array for video and a single-element dipole for audio. The B-29's engines and three 5-kVA, 500-Hz alternators powered the receivers and transmitters.

On June 23, 1948, Westinghouse used an airborne transmitter to rebroadcast the Republican National Convention in Philadelphia to a nine-state area. A ground-based receiver in Zanesville, Ohio provided proof that Stratovision could reach "small town and farm homes". The FCC's Freeze of 1948 remained in effect, however, and the greatest lessons of Stratovison would have to wait.

Editor's Note: Click here for Part 2 of this series. Many thanks to Transcendian for suggesting this topic.

Resources

http://www.museum.tv/archives/etv/F/htmlF/freezeof1/freezeof1.htm

http://www.screenonline.org.uk/tv/technology/technology6.html

http://en.wikipedia.org/wiki/Stump_the_Stars

http://www.amazon.com/Award-Winning-Nighttime-Television-1948-2004/dp/0786423293

http://philosophyofscienceportal.blogspot.com/2008/10/stratovisionprecursor-to-satellites.html

http://en.wikipedia.org/wiki/Stratovision

The Y Files

Steve Melito