But RKO was lucky that their competition suffered from inferior signals and poor ownership. That definitely helped KHJ defeat KRLA, KFRC over KYA and WRKO over WMEX.
When Drake and Jacobs took over KHJ, the ratings were done by Pulse and Hooper and did not include anything in the OC and also did not include most of the "Valleys" (both of which were much smaller in population). So signal was not an issue.
The same applied to San Francisco. KYA and KFRC had signal parity in the rated areas. It was not really until the 70's that Arbitron became dominant and the MSAs were much larger than the Pulse and Hooper ones, favoring signal.
Having been a KHJ PD for three miserable years, I can say that the KFWB signal was in many ways better than KHJ. KFWB is non-directional, and while located in a lower ground conductivity site, it is not directional at night. KHJ's signal at night to the SF Valley was less strong and even in Glendale and Pasadena it was kind of "ratty".
The one market where RKO did not dominate during the Drake years was Memphis. Although WHBQ was successful, they were often behind top 40 competitor WMPS which had a better signal and stable ownership with Plough.
From the time of the introduction of the Drake approach through around 1973, WHBQ pretty consistenly beat WMPS, but the battle was quite close at times. In 1974, WMPS was strongly the winner, but by laate 1975 it was back to being behind 560. In '77 and '78, it was WHBQ almost 3 to 1 over WMPS.
Of course, in the 60's and 70's almost all the time WDIA was ahead of either of them. Again, in the pre-Arbitron dominance years, the survey area did not disfavor either Top 40 station, even at night.
WHBQ finally defeated WMPS when Rick Dees was fired from WMPS and went to WHBQ. I would argue that when John Long was PD of WHBQ in the late 1970s, they sounded better than any of their sister RKO stations including KHJ.
Remember, Dees was in Birmingham well into the 70's and it was not until 1974 that his morning show on WMPS swung the ratings strongly towards them. In late 1976, suddenly WHBQ jumped way up and WMPS collapsed. In 1979, Dees went to LA and both WMPS and WHBQ were over bby then. In 1980, both averaged in the high 3's or low 4's in share, while WHRK on FM was nearly always #1 and in the double digits from 1980 till around 2002.
This is an interesting story! Dees once "thanked" me for making him leave WSGN in Birmingham, but I had never looked at "the rest of the story."