Philco 511 "Coffin" Radio & Model 211 Speaker (1928)
The "Spanish Brown" Philco model 511 table radio and
its matching model 211 loudspeaker, shown right, were
introduced in the summer of 1928. The 511 was one of
a group of models heralding Philco's entry into the radio
manufacturing arena. Until this time, the company's pri-
mary products had been batteries and battery-eliminat-
ors, but with the advent of ac-powered radios, sales
were declining and the products faced imminent obsol-
escence. In an effort to survive therefore, Philco divers-
ifed their operation into producing radios for the home.

The 511 table model had an original purchase price,
minus tubes, of $115. With $25 for the 211 speaker,
plus tubes, the price increased to around $160. In sup-
port of their radio sales, Philco expanded their already
widespread network of dealers and mounted an aggre-
ssive advertising campaign. The models were a moder-
ate success, as 96,000 were sold in about 6 months
(69,000 of which were table sets). As a result, Philco
ended 1928 in 26th place in US radio sales*.

The 511 is an all-electric socket-powered neutrodyne
receiver built into a metallic coffin-style cabinet. Also off-
ered were table models sharing the same cabinet style
as the 511 but painted in vivid base colors adorned with
hand-painted flowers. Philco promoted these sets by
"Now, for the first time, radio in color.
Vivid colors to harmonize with your home".
The color
models comprised the Mandarin Red 512 with matching
212 speaker, the Labrador Grey 513 with 213, the Nile
Green 514 with 214, and the impressionistic 515 with
215 speaker. All but the Spanish brown sets are comp-
aratively rare, with very few of the 515 known to exist.
These metallic sets were designed by Hollingsworth
Pearce, billed in Philco advertising as a leading author-
ity on cabinet design. Flowers were hand-painted un-
der the direction of Mlle. Messarios, a Philadelphia-
based artist. The design patent for the set's escutch-
eon, attributed to Pearce and filed in March of 1928,
can be viewed

Philco's inaugural series of radios was rounded out by
high-boy and low-boy models built into more traditional
furniture-style cabinets, described as Louis XVI period
style. These cabinets housed the same radio chassis
as the 511 series. The line also contained the model
concert grand loudspeaker, priced at $50, which
used the same driver type as the 211 series. It was des-
igned as a table upon which to sit a 511 series radio, as
shown to the right. Each of the furniture style cabinets
is attributed to Albert Carl Morowitz.

The model 511 is a 60Hz ac "socket-powered" radio
that covers the standard broadcast band from 550 -
1500 kcs. It uses 7 tubes:-  80 (rectifier), 71A (power
amp),  26 (first af), 27 (detector), 26*3 (3 triode-based
tuned RF stages). A bottom view of the set, with the
metal cover removed, can be seen
here and the
schematic is available online courtesy of NostalgiaAir. A
25Hz version of each model was also available (models

The 511's triodes (type 26) used for RF amplification
were neutralized to counteract the troublesome plate-
grid capacitance inherent in these devices. This capaci-
tance, in accordance with the so-called Miller Effect,
becomes magnified by the gain of the stage and without
neutralization renders the circuit practically useless as
an RF amplifier. Cognizant of this, Philco obtained a
license to use the Hazeltine Corporation's
neutrodyne circuit and enlisted their assistance in perf-
ecting the design.

In their ads, with what was to become typical hyperbole
and aplomb, Philco referred to their radio as being
"Neutrodyne Plus - a combination of the neutro-
dyne circuit PLUS super power"
and as a "New Rad-
io Discovery... a remarkable enlargement of the
neutrodyne principle - a discovery by Philco radio
Several typical ads can be seen in the
column to the right. Philco would re-use the phrase
New Radio Discovery several times over the years.

In March of 1928, in preparation for introducing their
line of radios, Philco purchased the
Timmons Radio
Products Company
of Philadelphia, manufacturer's of
battery eliminators and, more significantly, the
ons Talker
high impedance magnetic loudspeaker.
John Spence Timmons was the man behind this com-
pany and he stayed with Philco following the acquisi-
tion until his retirement in 1956. His speaker technol-
ogy formed the basis for Philco's 211 series. How-
ever, these loudspeakers were acoustically inferior to
the electrodynamic models then in use by some other
manufacturers, most notably Grigsby-Grunow.

* numbers sourced from
...vast distance range, split-hair selectivity and tremendous volume.
"...the cabinet stands forth as a highly artistic
ornament on its own account, exquisite in its
classic line, softly modulated in color"
Aug 23rd 1928, Oakland CA
Aug 27th 1928, Lowell MA
Aug 29th 1928, Syracuse NY
Dec 11th 1928, Illinois
Nov 13th 1928,
Canton, Ohio
Philco 511 Metallic Table Radio & 211 speaker (1928)
Philco Model 511 atop Concert Grand Speaker Cabinet
Philco 511 sitting atop the Concert Grand Speaker Cabinet
Newspaper clippings describing Philco's first
radio set. Sept and Dec 9th 1928.
Dec 22nd 1928, Pa
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