- 560 - WFIL-AM - Philadelphia, PA
- 660 - WEAF-AM - New York, NY
- 770 - WJZ-AM - New York, NY
- 830 - WEEU-AM - Reading, PA
- 1060 - KYW-AM - Philadelphia, PA
- 1210 - WCAU-AM - Philadelphia, PA
- 1340 - WRAW-AM- Reading, PA
Now I have to acknowledge that KYW used to be on 1020 in Chicago prior to 1934, and that today the WJZ-AM callsign is on 1300 AM in Baltimore. While WFIL and KYW have remained in Philly with the same calls, stability is no good for this exercise. The WEAF-AM calls now reside on 1130 AM in Camden, South Carolina. But we can safely ignore that geographic outlier.
The two local Reading stations certainly place this radio in Reading, PA area living room. WRAW signed on in 1922 at 1260, but only at 100 watts. It didn't get a bump up to 250 watts until the 1950s on 1310, then moved to 1340 in the 1960s. It was WKAP from 2007 to February 2014 but returned to it's heritage calls that Spring.
WCAU signed on in 1922 as well, at 250 watts. They stuck with those call letters for 68 years becoming WOGL in 1990 flipping to oldies. They became WGMP in 1994 trying out sports talk, the just plain talk as WPTS 2 years later, 30 days after that they changed it again to WPHT which has endured since. Their stability again tells us very little.
WJZ started in Newark, NJ in 1921 and moved to New York in 1923 when it was sold to RCA. In 1927 it became the flagship of the NBC blue network. It became WABC in 1953 which helps to date this radio dial. WEAF also signed on in 1922, but those calls changed to WNBC in 1946 following the Blue Network divestiture. So this radio must predate that even change.
So the KYW timeline tells us that the radio must post date 1934, and WEAF, that it must pre-date 1946. Surprisingly it must have included WRAW while it was still at 100 watts. It's not a very tight range but it's not what you know, it's what you can prove.