DEVELOPMENT OF THE AM BROADCAST BAND

Herewith the stories of dial-jumping, ‘The Chaos of 1926’ and the fickleness of the Feds.  Many of the earliest .pdfs below deal with channel assignments in wavelengths rather than frequencies; you’ll find wavelength conversion tables below as well as news copy detailing the change in lexicon through the 1920’s.  In fairness, no one could have foreseen the awesome appetite for frequencies and the “Sheriffs of the Airwaves” had no choice but to keep re-plotting the assignment layouts to try to keep up…much less plan ahead.  Many of the early stations were clustered together in two or three wavelengths according to their so-called “purpose” and after the band was “opened up” many stations were moved three or four times before finally settling in: just in time for the wholesale frequency-reassignment of NARBA 1941 and the subsequent fine-tuning of the RIO Conference.

Much of the early dial confusion and interference resulted from the lack of frequency-control (as tubes warmed up, stations ‘wandered’) and in some cases from the Libertarian desire to move one’s station to a “clear spot on the dial” rather than stay on their assigned (and over-crowded) wavelengths.  The massive mess finally resulted in stiff Federal legislation.  And the radios themselves; particular those known as “squealers” had to be replaced en masse. 

TIME-SHARING was an ill-fated third idea to reduce congestion when it was seen that each market had fewer assigned frequencies than it had allocated station licenses. Time-sharing worked for a short while, but as stations grew successful they pushed hard for full-time authority on their channel. 

This page like the others will be continually expanded.  Related stories will be found in the accompanying pages “Early Radio Regulations” and “Early Radio Technology.” 

Enjoy the stories!

This material is provided for use by Educators and Researchers.  No copyrights or usage rights are implied or granted.