Emerson 540A (540) "Emersonette" Midget Radio (1947)
The Emerson model 540/540A, introduced in
early 1947, features a tiny cabinet housing an
All-American-Five (AA5) AC/DC superhet tuning
the standard broadcast band. It was offered in
a choice of four different colors of plastic:-
walnut bakelite, ivory plaskon, red plaskon and
mint green plaskon. All had black bullet style
knobs. The 540 was advertised as "
the world's
smallest ac/dc superhet
" and in walnut it had an
original list price of $19.95. Other colors were
priced  $5 more at $24.95.

The cases are very fragile and as a result
relatively few have survived. Today, the 540 is
highly collectible and the red and green ones in
clean, undamaged condition can command a
price that runs into four figures!

Frequency coverage is from 540 -1620kc. The
540 uses the AA5 minitaure tube complement:-
12BE6 (mixer/LO), 12BA6 (IF amp), 12AT6
(2nd detector/AVC/1st AF), 50B5 (AF output)
and 35W4 (rectifier).  
540A Schematic.

The 540's styling is very similar to the pre-war
CF-255 from 1939. However,  due to
the larger tube technology available back at
that time, the CF-255 had to make do with just
two tubes!
The rear of the cabinet
has a cardboard back
that bows out to accom-
modate a loop antenna.
extract from 1947 newspaper ad
Emerson 540A Radio in red plaskon (1947)
...the world's smallest ac/dc superhet...
...a handful of power and miracle tone...
Emerson 540A (walnut bakelite)
Diminutive size!
Emerson 540A (rear)
Clipping from April 20th 1947
Emerson 540 Radio in mint green plaskon
...a small thoroughbred in every radio respect.
                  540 or 540A?
The Rider's manual has three pages for the
model 540A (
17-19, 17-20 and 17-21 for chassis
120042A) and three additional pages for the 540
18-7, 18-8 and 18-9, shared with models 564
and 572, for chassis 120042). The two chassis
appear to be the same, other than changes to a
few part numbers, such as the second IF trans-
former. The cases, dials, knobs, etc. are identical
between the models, with the sole exception that
the cabinet parts list for the 540 includes a black
bakelite cabinet in addition to the red, green,
walnut and ivory offered for the 540A. I have never
seen the black cabinet, nor have I found any
advertising that mentions it. The 540 probably
preceded the 540A, even though its Riders pages
appear in a later volume (18 versus 17 for the
540A). All advertising I found simply refers to the
set as "model 540".

This all leads me to conclude that there is little
practical difference between the models from a
user's or modern collector's perspective. Note
that the model number is stamped on the rear
cover. However this is indecipherable on all but
one of my sets.
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Emerson 540 Radio in mint ivory plaskon