In Queens NYC back in the 60's -- that's the 1960's, hi -- we each had the divvil of a time hearing KFI. We didn't know of loops, and were still fuzzy on any 'directional' stations. The White's Radio Station guides in the monthly Radio-TV Experimenter magazine were all we had.
It did seem odd that a few of us logged KNX before we nabbed KFI -- moreso because, well, both turned out to be 50K omnis '24/7. And near JFK Airport* the nighttime 640 spot was fun WHLO Akron that signed off at L.A. sunset ; then the occasional 10,000 omni CBN from Newfoundland and CMQ from Cuba. That was the lot. By comparison, 1070 then had over a dozen full-time US stations on it.
So, am wondering if some form of atmospheric effects -- Aurora or lack of it -- was a factor with KFI. Really, back then when the dial was so less crowded there was no reason why a 50,000 watt omni had trouble making it at least occasionally across the country.
Would enjoy reading some exploits from West Coast DXers from that era, vis-a-vis reception of East Coast 50,000-watt omnis like WGY 810, WHAM 1180, KDKA 1020, WNBC 660, WCBS 880, etc ........ how it was before KOB 770, KDWN 720, KTWO 1030, KOFI 1180 et al got assigned to do their things.
* When we started DXing, the thing was called 'Idlewild International'