One thing that many people don't know is that Docket 80-90 and subsequent related rule makings actually INCREASED many distance separation requirements, particularly Class A to Class A and Class A to Class B minimum distance requirements for allotments, and left many existing 3 kW Class As with no way to meaningfully upgrade to 6 kW. Directional 6 kW Class As were better off with 3 kW nondirectional in many cases. In the case of Class As and Class Bs to Class Bs, that used to require 40 miles on second and third adjacent channels, the increase to 43 or 46 miles often requires ridiculously directional antennas, and the actual measured pattern is often even much worse than the stylized FCC pattern envelope, where full nondirectional facilities used to be allowed. This is based on circa 1960 FM radio performance, which has improved substantially over the years. Gone are the days of tube radios with AFC where strong local stations blotted out everything 600 kHz or more from the local station. You might find a few still in existence at antique shows and stored away, but not regularly used. The oscillators in those also often exceed Part 15 radiation limits. This manifested itself with interference to radios in neighbors' homes, and even bizarre and perplexing IF Beat interference complaints that station engineers were initially at a loss to explain when called out to peoples' homes.
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