August 1941 Radio-Craft
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Craft,
published 1929 - 1953. All copyrights are hereby acknowledged.
Lafayette Radio & TV Corp. Model
(left) and B-103
(right) Console Radios (radiomuseum.org image)
The Radio Service Data Sheets that were published in Radio−Craft usually
seem to have more information included than those published in other magazines,
at least in the same era (1940-ish). It might have to do with how much material
is provided by the manufacturer rather than a decision by the magazine editors.
Either way, here are the schematics, chassis layout, and service info for the Lafayette
Model B−100 through B−103. As with most radios built in the era, the woodwork and
artistic design of the cabinet are exquisite. There are still people searching for
such data, but fortunately the Internet is making it much easier to locate. None
of the three models show up on eBay as of this writing.
Lafayette Chassis Model B-100 (Table Model B-103; Console
Models B-101, B-102) Radio Service Data Sheet
A 9-Tube, 5-Band A.C. Superhet., with Tuned
R.F. Stage on All Bands; A.V.C.; Automatic Bass Compensation; High-Q Loop Antenna;
Self-contained Counterpoise Antenna; Provision for Outdoor Antenna; Mechanical 6-Pushbutton
Tuning; Edge-lighted Sliderule Dial; Tuning "Eye"; Provision for Phonograph or Automatic
Phonograph and Recording Microphone (and therefore Television and F.M. Adapters).
and for an External Loudspeaker. Consoles use up to 14-in. Speaker; Table model,
8-in. Power Consumption, 75 Watts (117 V., 60 cycles); Power Output, 9.5 W. undistorted,
11 W. max.
The Model B-100 Chassis is used in a series including phonograph combinations
equipped with an automatic record changer. Models not equipped with record player
are provided with facilities for the playing of records through the radio set (see
illustration showing parts placement atop chassis and at rear). Volume and tone
control are used in the same manner for phonograph reproduction as for radio reception.
Selectivity at 1,000 times signal strength. 30 kc, broad. The Tone Control affords
radio reception when turned to far right until a click is heard, and then backed-up
for tone control; phonograph operation is obtained when this knob is turned to the
far left until the click is heard, and then turned forward for tone control.
Setting Buttons. - When setting-up the manual pushbutton tuning buttons, it is
preferable to follow in a kilocycle sequence, starting with the lowest kc. setting
at left. To set a button, unlock the pushbutton mechanism from the back of the radio
receiver. On the drive pulley shaft and at the left side (from the back of the radio
set) of the pushbutton tuning assembly is a locking screw (see Fig. 1). Turn
the manual tuning knob until the locking screw is available and loosen it with a
small-handled screwdriver. To set stations accurately do not jar the radio set or
the buttons while the mechanism is unlocked. Having tuned in a station to accurate
resonance, by means of the tuning eye, hold the manual tuning knob with one hand
and with the other push one of the station buttons all the way in. Double-check
the resonance, meanwhile holding the button all the way in, then slowly release
the button. Do not touch this button again while the mechanism is unlocked. Now
tune-in the second station following the same procedure; and so-on for the remaining
buttons. After all the stations are set, the mechanism is locked by turning the
manual tuning knob until the locking screw can be easily reached; with a small-handled
screwdriver, the locking screw is then tightened.
Antenna and Ground. - Two built-in aerials
are incorporated in the cabinet. One is a loop type for broadcast reception and
the other is a counterpoise foil aerial used for reception on shortwave bands. For
reception of nearby stations, an outside antenna and ground are usually not required,
however if local noise is excessive it may be desirable to use an outside antenna,
in which case it should be about 50 to 60 feet long including lead-in. In the console
models, when operating the radio set on broadcast band with the built-in loop antenna,
directional effects are obtained; in the loudspeaker compartment is a rotatable
loop antenna. In the table model receivers the loop is fixed.
For best shortwave reception an outside antenna and ground are recommended.
A wire with an antenna marker will be found coming out of the chassis. If the
loop and counterpoise foil aerials are used do not connect this wire to anything.
If an outside antenna is used, connect this wire to the lead from the outside antenna.
The wire which is connected to the counterpoise foil aerial should never be disconnected.
On the back of the chassis is the socket for record-player connections. The cable
connector must be a single shielded pin. Part No. BA224. On the top of the chassis
is an A.C. phono motor socket. On the back of the chassis is a socket to which a
microphone preamplifier may be connected. The speaker socket provides connections
for the record cutter and power for the preamplifier. Dial lamps are bulb No, 51.
bayonet pin type.
Posted December 8, 2022
(updated from original
post on 4/19/2015)