Zenith Model 9-S-367 Console Radio (1939)
The Zenith 9-S-367 (9S367) is a 9-tube model from 1939 providing
coverage over three wavebands. It features Zenith's "robot dial", first
introduced in 1938. When the "miracle switch" (band select lever) is
operated to change between bands, an alternate dial or shutter is
rotated into view, showing the markings solely for the chosen band.
This renders operation of the set less confusing to the listener, so
much so that Zenith advertising posited that "it's child's play to operate a
Zenith and a child delights in doing it". It was further claimed that "the Robot
Dial is Almost Human" and that it was "the greatest advancement in ease of
tuning since the inception of radio". Certainly these dials are very much a
favorite amongst today's vintage radio collectors! The robot dial was
used on Zenith's 1939 sets having 9 or more tubes.
The radio photographed here has original brown plastic knobs below
the dial, though this model also appears to have left the factory with
ivory colored knobs.
The cabinet is often referred to as Zephyr style, after the streamlined
locomotive designs of the 1930's. The wrap-around louvers in
particular convey the impression of streamlined machine-age form and
This is a very nice sounding Zenith but for some reason it's not one of
the best sounding, in my opinion. Perhaps it's because the 12"
speaker is close to the floor or because it has a small grille area that is
partially obstructed by the horizontal louvers.
The tube line up for this radio is 6F6G, 5Y4G, 6J5*2, 6L7G, 6F5G,
6U5G, 6K7G*2. It uses a single ended 6F6G output stage. Schematic.
I bought this radio from a local seller on Ebay. When I got it home and tested it, it
was non-functional. I noted that the 5Y4G rectifier was not lit up and upon closer
examination it became clear that the 5Y4G tube socket had been re-wired at
some point in the past to accept a 5Y3 tube (same characteristics but different
pin-out) but that the 5Y3 had been replaced with a 5Y4G again sometime later. I
substituted a 5Y3 and this radio did work in a brief test. Since that time I have
completely re-capped this radio and replaced numerous out-of-spec resistors.
The shutter dial mechanism was cleaned and lubricated. The tuning belt was
good (clearly having been replaced in more recent times). I re-wired the rectifier
socket back to accept a 5Y4 and replaced both the 6U5 tuning eye and the
infamous 1Meg resistor in its socket.
..with robot dial ...its almost human.