Philco Model 90 Cathedral Radio (1931)
The Philco Model 90 is the most desired cathedral radio of all
time in the eyes of many collectors. Designed by Edward Combs,
its classic lines epitomize the cathedral style, which
became wildly popular in the 1930s.
Model 90 Supersedes Model 20
In 1930, the year before the Model 90's introduction, Philco had
scored a home run with
its "midget" Model 20, a tabletop radio with a rounded cathedral
cabinet, offering the same performance as much larger console radios in
a smaller, cheaper package.
Prior to that time, most radios came in one of two packages. Console,
or floor-standing models, came in squarish (sometimes ornate) wooden
cabinets, usually standing on thin wooden legs. Tabletop models generally
came in plain, coffin-shaped boxes.
The new "midget" cabinet was much smaller than contemporary
consoles, yet more attractive than the coffin style tabletops of the 1920s.
Philco sales skyrocketed, quickly launching the
company to the top of the US radio market. (Philco was not the first
manufacturer to offer a cathedral cabinet, however. That honor belongs
to Jackson Bell for their 1929 cathedrals, and possibly one or two
other minor manufacturers.)
The 1931 Philco Model 90 capitalized on the success of Model 20 and added some
key innovations. First, it adopted the newer superheterodyne electronic
design, which offered better performance than the finicky TRF (tuned regenerative frequency) design and was ultimately embraced by all radio manufacturers.
The 90 also added a tone control, which is the leftmost knob as you
look at the front. It's a simple two-position treble/bass type control.
Click it to the left for more treble, and to the right for more bass.
Model 90 employed nine tubes compared to the seven of Model 20. The tube lineup is as follows: 80, 24, 27, 24, 24, 24, 27, 45, 45.
The Model 90 cabinet is more sophisticated and dressy than that of the Model
20, which has the same general size and shape, with a fancy grille, but an
otherwise plain-Jane front panel.
The Model 90 cabinet adds stately columns at the sides of
the cabinet, creating a distinctive "Gothic arch" appearance. It also
adds discrete feet at the bottom corners, along with more complicated
beveling and pattern-matched veneer in the upper front perimeter.
Judging by continued interest over the decades, this has to rank as one
of the most successful and pleasing of all cathedral radio designs.
Despite the "midget" appellation, this is a large, heavy
tabletop by modern standards. (It's a midget only in comparison to
a full-sized console radio.) If you ship one of these sets, I advise
removing both the chassis and the speaker and packing them in separate
boxes. If they are left in place and the box is dropped, the heavy
chassis may crash right through the bottom of the cabinet. Even
worse things might happen if the radio happened to fall on its face.
Two Model 90 Versions
All Philco 90s have the same cabinet, but there are two different
electronic versions. Mine is the early one, which
used two type 45 tubes in a "push-pull" circuit to provide
high-quality (and loud!) audio output.
This early version of the Philco 90 did not use automatic
volume control (AVC), also known as automatic gain control (AGC).
Put simply, AVC smooths out the signal strength between very strong
local broadcast stations and faint, distant stations.
If you are listening
to a radio without AVC, the difference is obvious as you turn the tuner.
If you turn up the volume far enough to receive a faint distant
station, the radio will blast your ears off when you tune into
a strong local station.
The second version of Model 90, introduced in October, 1931, used a single
type 47 tube for audio output and it did have AVC, making "station surfing"
a less ear-shattering experience.
The earlier version of the 90 also has a two-position "Local/Distant" switch on the back of the chassis. The toggle switch is visible in the
following photo, near the center of the chassis back.
If you plan to change from a strong local station
to a faint, distant station, you would flip the switch from Local to
Distant. This turns up the gain on the receiver for the faint station, an
operation that is done automatically with AVC.
The smallest, centrally located, knob is the radio's power switch. Next to
it is the volume control. Later
radios incorporated the power switch with the volume control, an
arrangement that quickly became universal.
One Cabinet for Several Radios
If you find a radio with this cabinet, look carefully at the details. More
than one Philco model was offered in this cabinet, and there is even a
modern transistorized reproduction that (although smaller) bears a strong
During the same years as the Model 90, Philco also sold the Model 70,
a cathedral with the same cabinet but only seven tubes and somewhat
lesser performance. The 70 outsold the 90 by a factor of more than two
to one, so if you want a vintage cathedral that looks like this but
you don't care so much about its performance, a 70 is a fine choice.
Another Philco using this cabinet is the model 21. It is easy to distinguish
from the Model 90 because it lacks a tone control, hence it has only three
knobs rather than four. The 21 is essentially a Model 20 in a newer
cabinet, using the older TRF technology.
Here is the drawing from the design patent application (number D83,956)
for the Model 21 cabinet.
If you own a model 21, 70 or 90, you can frame a printout of this drawing
to hang next to your radio.
Since the model 70/90 cabinet differs only in the number and placement of knobs,
I believe Philco did not file a separate design patent for that cabinet.
Incidentally, if you know the patent number, you can look up all sorts
of interesting radio patents at the
US Patent & Trademark website.
When I looked up this patent, I discovered an odd thing. Patent number
D83,957 (next in numerical sequence) was filed on the same day as this one and
it shows exactly the
same cabinet—only without any grille opening for the speaker! Perhaps Philco wanted
to patent the basic fluted-column cathedral design and reserve the
ability to use some other grille design.
Who knows? In any case, the columnar design was not repeated by Philco during
the next few years. Cathedrals of that vintage tend to have flat fronts without
columns, similar to my Model 60B.
My model 90 was fully restored when I bought it, so I don't have a
restoration story to tell about it. This is the only fully restored
set that I have ever bought. I don't think I will do that again. There's
nothing wrong with this radio, but to me, restoration is the most
interesting part of radio collecting!