 It allocated one hundred FM channels from 88–108 MHz, and assigned the former FM band to 'non government fixed and mobile' (42–44 MHz), and television channel 1 (44–50 MHz), curiously avoiding the subject of the effects of tropospheric and Sporadic E propagation on those services.A period of allowing existing FM stations to broadcast on both low and high bands followed, though as late as 1947, in Detroit, there were only 3,000 FM receivers in use for the new band, and 21,000 for the old band.The dual band transition period ended at midnight on January 8, 1949, at which time any low band transmitters had to be shut down, officially making obsolete 395,000 receivers that had already been purchased by the public for the original band.