Stewart-Warner Model 91-531 Tombstone Radio (1938)
A charming smaller tombstone with exceptionally pretty
veneer, this radio was well cared for. The
cabinet looked almost like new when I found it. In a Ziploc bag tucked
inside the back, I also found the original owner's manual
plus copies of the Rider's service sheets.
This radio is considerably smaller
than my full-sized GE S-22X Tombstone.
It also has a very different look. The GE is large,
dark, and ornate; it would not look out of place next to most 1920s radios.
This Stewart-Warner is streamlined, gently rounding at top
of the cabinet and horizontal grille louvers. It look more like
a 1940s radio, although it was made only four years
later ((1938) than the GE set (1934).
The round knobs are original and they are molded
with a graceful S/W logo. Surrounding the dial and pusbuttons are two
decorative escutcheons with raised lines of lacquered brass
on a black background.
This radio receives the usual BC (AM) band from 540-1725 Khz
and shortwave broadcasts from 5.4-15.4 Mhz. Below the tuning dial
are several pushbuttons. The leftmost button, labeled Speech, is
a tone control. When the Speech button is pushed in, it accentuates
the treble, making speech more audible. When pulled out,
it accentuates the bass.
The rightmost button, labeled Foreign, selects the shortwave band.
Next to it is the Broadcast button, which both selects AM reception
and allows you to set the five preset tuning buttons.
As in my Zenith 12-A-471 and Crosley 146CS, the preset
tuners work electronically rather than with mechanical gizmos
that drive the tuning capacitor. Setting them requires
removing the lower escutcheon to expose the adjustment screws.
To set an individual button, you push in the Broadcast button and
tune the desired station as usual. Each button has a predefined
frequency range (for example, 550-1000 Khz), so you must
choose a station within that button's range. Then you push in the
chosen button and adjust its two trimmer screws until you receive
the station clearly with maximum volume.
The radio originally came with a sheet of pre-printed call letters,
which you could insert in the button's face once you set it to that
station. I suppose the sheet of extra call letters was the first
thing that most owners discarded. In any case, I have never found a
radio that included this bit of ephemera.
Inside the cabinet is Stewart-Warner chassis number 91-53, a conventional
five-tube superheterodyne receiver. This chassis was used in models 91-531 to 91-539, according to
the Rider's sheet. The other models probably housed the same chassis
in different style cabinets. Here's the tube lineup:
||2nd detector/AVC/AF amplifier
Restoring the cabinet finish took only a few minutes. After
removing the chassis and hardware, I cleaned the cabinet with
paint thinner and a soft cloth. Then I wiped on a coat of
Minwax Special Walnut finish. After letting the Minwax set
for about two minutes, I rubbed it off again, then vigorously
buffed the whole cabinet with a clean, dry cloth.
This treatment darkened any little scratches on the cabinet, making
them blend in almost invisibly, without otherwise changing the
finish, other than to impart a nice shine. If you left the Minwax
on for a longer time, or didn't rub it off so aggressively, it
would darken the original finish, of course. The trick to this
technique is that you remove almost all of the Minwax, except
for what's left behind in the scratches.
I haven't had time to delve into the electronics yet.
Repairing it should be no more difficult than fixing any other
"All American Five" radio. It was obviously serviced at some
time in the past. Two or three of the old paper capacitors were
replaced with plastic "Black Beauty" capacitors. Unfortunately,
those early plastic capacitors were just as unreliable as the
paper ones which they replaced! You can read more about capacitors
in Replacing Capacitors in Old Radios.
Other tombstones in my collection include a 1937 Philco
37-61, a 1937 Zenith 6-J-230, and the
GE S-22X mentioned earlier.