[Jeffhs]

The radio being discussed probably dates to the '60s or possibly later, as Zenith used the 99.5-Mc. marker dot on most (but not all) of its AM/FM and FM-only radios until about the late 1970s--years after WEFM, Zenith's operated FM station, left the air.

I don't know exactly when WEFM left 99.5 MHz in Chicago, although the WEFM calls were in use on 99.5 as late as 1976; the switch to WUSN may have occurred in the late '70s or early eighties. I did a Google search a few moments ago and found out just what stations followed WEFM--right up to 99.5's current occupant in the city, WUSN "US-99.5" country-western. The station began as W9XEN, later to become, in order, W51C, WWZR, WEFM, then WUSN, the call sign it holds today.

WEFM was a classical station in the '50s and early '60s, predating Chicago's current classical FM, WFMT 98.7 (not to mention several NPR affiliates in the city and its suburbs which also program classical) by some years. WEFM was also one of the first U.S. FM stations to broadcast in stereo using the FCC's then-new multiplex standards; it put its stereo signal on the air on June 1, 1961. The other pioneer in FM stereo broadcasting was WGFM, Schenectady, New York, operated by General Electric, which began stereo broadcasts on the same date.

That little white dot near 100 MHz on our treasured old Zenith radios has no significance today, except perhaps to mark 99.5 for alignment purposes. But believe me, if that dot could talk, it would tell one story after another about the three Chicago FM stations that preceded WUSN. Someone should write a book (probably already has).