H.P. Richter's "Wiring Simplified" 1936 edition shows a radio outlet with a double T power connection and what appear to be "meter jacks" for aerial and ground. (not banana jacks but test prod type jacks)
The 1938 edition shows the same.
The 1941 edition shows the outlet pictured in this thread.
The 1946 & 1948 editions show the same.
The 1954 edition no longer shows a radio outlet.
It does however show a "special Laundry Receptacle" stating that the 1953 code requires one in every Laundry room.
It is what we now call a NEMA 5-15 duplex.
