An example of this VHF interference problem was noted in the wikipedia for WGAL-TV, signed on as VHF 4 on March 18, 1949. It wasnt until 1952, that competition in the form of UHF came to this area from towns only 25 miles apart, bowties were everywhere
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"In 1952, WGAL increased its power from 1,000 to 7,200 watts. On December 31, 1952, the station moved to channel 8 as a requirement by the FCC in order to prevent interference with WRC-TV in Washington.....
On January 1, 1954, WGAL presented its first color television broadcast of the Tournament of Roses Parade. It has always been an NBC affiliate, but also carried some programs from CBS, DuMont and ABC until 1963"
Most TVs owned locally are RCAs prior to '52 and all sets were sold with UHF tuners if later than 52. Brand loyalty in an area where RCA employed many people at the New Holland Ave plant making vidicon and CRTs explained much of WGAL's early adoption of technology. Zenith really only became popular after mid-60s.