The Eveready "30" Receivers
The Eveready "Model 34" Console.
The National Carbon Co.'s line of Eveready receivers
presents the same chassis, the "Model 30," in a choice of
consoles. The receiver, a R.F.L. design. has variometer
tuning in the antenna circuit, and six stages, using four
27s and push-pull '71s. All console models have the Eveready
dynamic reproducer built in.
Silver A.C. Short-Wave "735"
Chassis of the "Round-the-World Six," a 17 to 650 meter
factory assembled receiver.
This receiver is designed to take short-wave reception
off the breadboard and into the parlor. Its circuit is similar
to that of the D.C. "735" which is also available; the latter
uses one '22 in an untuned R. F. stage, and four 12As. The
A.C. model uses a '24 with its superior characteristics
in the first stage, and has a '45 push-pull output. The
audio channel and power unit are the same as in the "Model
722" - "Band Selector Seven". The "735" A.C. model lists
at $64.90, factory assembled. without cabinet or long wave
Set Tester And Checker
The Weston "Model 533" Counter Checker.
Thirteen ranges are combined in the new Weston "Model
547" Set Tester, which measures both A.C. and D.C. voltages
up to 750, by means of its two selector switches. Three
3 1/4-inch meters are incorporated in the panel. The instrument,
with the necessary tools and testing accessories, weighs
ten pounds and fits in a carrying case 12 3/8 x 9 x 3 3/4
inches. Its net (dealer's) price is $93.75.
The counter rube checker is adapted for operation from
any standard A.C. lighting circuit, with considerable tolerance
of input voltages; and is designed to test quickly all the
latest A.C. as well as D.C. rubes for their characteristics.
Brandes And Kolster Remote Tuners
The Brandes "Model B15," with its selector tuner above.
The Kolster and Brandes receivers of this season incorporate
a new method of automatically-selective tuning.
The Kolster "K-45" has no knobs or dials on the front;
its dial may be seen through a small window in the top.
and the tuning buttons are on the side. In addition. there
is a remote-control box, led by a cable to the set, which
has six buttons for as many stations, volume control, switch
and pilot lights. The list price of this de luxe set is
$500; other models range down to $200.
Above, the remote-control tuning box of the Kolsrer "K-45;"
at the left, the automatic selector built into the set itself.
By modern house-wiring methods, any room can be equipped
with a receptacle, thus allowing a convenient disposition
of the tuning box wherever desired.
The Brandes brings the selector tuning system into a
lower price range. This line has also four tuned circuits
and '45 push-pull amplification. The "Model B-15" illustrated
lists for $125.50; the line covers the field from $85 to
De Forest Audions
the line of new tubes presented by the de Forest Radio Co.,
an improved heater design has been incorporated to reduce
the hum of the A. C. filament current. The heaters now used
are made of "crolite," a new synthetic ceramic; and the
filament is completely shielded from the cathode. In the
410 power tube, as in the new D.C. screen-grid audion (the
422), oxide-coated filaments are used to give longer life
than with the thoriared-tungsten commonly used. In the new
424, the A. C. screen-grid audion, other characteristics
have been retained, but the grid bias has been doubled.
The Crosley "Monotrad" in a table-type metal cabinet,
designed to take the speaker as shown or on top.
In the Crosley line of mass-production price receivers,
the newest arrival is the Monotrad, a seven-tube A.C. screen-grid
receiver, listing at $62 without accessories. Its chassis,
illustrated below, has the new Crosley triple-range control,
a completely-shielded gang condenser carbon-type amplification
control and Mershon condenser. It is intended for use in
any of the many cabinets designed for the Crosley line.
The chassis of the Crosley "Monotrad."
Majestic Receiver Models
The post-colonial console design of the "Model 181."
The Majestic line incorporates, in its "Models 91 and
92," the latest type of power detection. These receivers,
with built-in super-dynamic reproducers, list at $137.50
The "Model 181," illustrated above, is a striking accomplishment
in cabinet work, and reproduces either radio or phonograph
records through a '50 push-pull amplifier. List, $316.50.
Zenith Remote-Tuner System
The Zenith "50 Screen-Grid" Chassis (above) and Automatic
Tuner (below, right).
newest Zenith designs Incorporate the "Model 50" chassis,
with its five tuned R.F. circuits, and two push-pull audio
stages, with '45 output. All embody the Zenith automatic
tuning system, to which has just been added (in the "Model
55") the remote tuner illustrated. This operates at the
turn of a button, its pilot light automatically indicating
the station which is on; and gives also volume control.
The set operates a 12·inch dynamic reproducer. The "Model
55" is priced at $700 in its Italian Renaissance cabinet;
others down to $175.
Champion Radio Tubes
new method of merchandising of interest to buyers, as well
as sellers, is utilized in the packing of Champion tubes.
Not only is there the new system of packing the complete
tube equipment for a given receiver in one carton; but the
individual tube is in a stout container of a design which
permits a demonstration test of its characteristics without
removing it or breaking the seal by means of a test adapter
furnished by the manufacturers.
Hammarlund Amplifying Units and Transformers
The Harnmarlund Manufacturing Co. has just added to its
extensive list of radio components several important units;
among them a three-stage R.F. band-selector, known as "BS-3,"
to work ahead of an amplifier; a three-stage screen-grid
R.F. amplifier, "RF-3," to follow the former; a shielded,
polarized R.F. choke, SPC, and a family of audio-frequency
The band filter comprises a three-gang "Midline" condenser
and matched filter coils; this affords pure 10-kc. selectivity
ahead of the amplification. The amplifier also contains
a three-gang condenser and matched, shielded coils. Both
units are factory assembled and sealed.
In front, the "Battleship" condenser of the band filter;
behind it, the coils in their shields.
The first-stage A.F. transformer, "AF-2," has a ratio
of 1 1/2-1; the push-pull input type, "AF·4," 2-1 on each
side. Both have very large primaries, and cores of special-alloy
laminations to insure a flat characteristic. The output
transformer types are "AF-M" for magnetic reproducers and
"AF-D" for dynamics.
A complete power supply unit, "PS-45," is designed to
operate a receiver with push-pull '45 amplification. It
comprises two heavy chokes and a power transformer with
primary tapped at 80 volts for use with an automatic voltage
regulator. The high-voltage secondary is a center-tapped
750-volt winding with a rating of 100 milliamperes; and
there are a 5·volt and two 2 1/2·volt windings. The new
voltage divider is "RHQ-30" and the condenser block "CHQ-30."
The new A.F. transformer in its steel housing for sub-base
Jewell "581" Test Panel
The Jewell Electrical Instrument Co. has designed a laboratory
panel, suitable for shop or jobber's use, to facilitate
complete testing of receivers and other radio apparatus
in the shortest time. It is furnished with high-resistance
precision meters and gives in addition to tube readings,
condenser capacities and high-voltage secondary readings.
Dealer's price $159; with work bench, $208.87.
Readings of the seven large (5 inch) meters of the Jewell
Test Panel are visible at a glance. It is a time-saver;
and time is money, even in the radio business. There is
a tube socket at the lower right for testing rubes apart
from a set.
"General" Wood Cabinets
The increasing vogue of individuality, in cabinets to
take standard receiver chasses, has promoted the production
of many very artistic designs. The Wood Cabinet Corporation
presents a line, of which the "Model 108" is illustrated;
it is designed to accommodate any popular set, with speaker
An attractive and somewhat modernistic piece of cabinet
Best Electric Motor Chassis
The "BBL" electric motor, designed for small-cone reproducers,
incorporates a tapped winding with a switch, which matches
the output impedance of the receiver without resorting to
a special transformer, as well as a separate volume control.
It is now available in a separate cabinet, at $35 list,
as well as in chassis form at $22.50.
The magnetic reproducer unit of the "BBL" motor will
drive a 12-inch fixed-edge diaphragm.