Stromberg-Carlson 235 Engineering Data

Engineering Data
Stromberg-Carlson No. 235 Radio Receivers
STROMBERG-CARLSON TELEPHONE MANUFACTURING COMPANY
Rochester, New York
ELECTRICAL SPECIFICATIONS
Type of Circuit_Superheterodyne with A. F. C. Electric Tuning
Tuning Ranges_A—530 to 1700 Kc.; B-1700 to 5600 Kc.; C-5600 to 18,000 Kc.
Number and Type of Tubes_1 No. 6A8, 1 No. 6J5,1 No. 6K7, 1 No. 6H6,1 No. 6B8,1 No. 6F6, 1 No. 6U5, 1 No. 5Y4G
Voltage Rating_105 to 125 Volts
Frequency Rating_25 to 60 Cycles and 50 to 60 Cycles
Input Power Rating_70 Watts
APPARATUS SPECIFICATIONS
No. 235-H Receiver_50 to 60 Cycles; P-28534 Chassis; P-26171 Loud Speaker
No. 235-HB Receiver_25 to 60 Cycles; P-28535 Chassis; P-26171 Loud Speaker
No. 235-L Receiver_50 to 60 Cycles; P-28534 Chassis; P-27375 Loud Speaker
No. 235-LB Receiver_25 to 60 Cycles; P-28535 Chassis; P-27375 Loud Speaker
CIRCUIT DESCRIPTION
The Stromberg-Carlson No. 235 Radio Receivers are eight tube, "Electric Tuning", superheterodyne receiv¬
ers and have three tuning ranges. Either "Manual" or "Electric" tuning is easily obtainable by simply rotating
the "Manual-Electric" tuning control knob to the desired position; when the Manual-Electric tuning control
knob is set so that the arrow on the knob points in the direction of the word "Manual", the tuning dial of the
receiver is illuminated and when the arrow on this control knob points in the direction of the word "Electric"
the call letters of the six stations which are set-up for electric tuning become illuminated. When it is desired
to tune in stations located in either the Medium Wave or Short-Wave ranges, the electric tuning arrangement is
made inoperative. The electric tuning circuit is arranged so that six favorite stations located in the Standard
Broadcast range may be set-up for instantaneous selection by means of the push-buttons (Local and other sta¬
tions that give the best daytime and evening service should be selected). To properly set-up the electric tuning
arrangement for the six favorite broadcast stations, read the section, "Instructions for Setting Up the Electric
Tuning Arrangement" appearing on page 6 of these instructions. When manually tuning these receivers or
when setting up the six desired stations for electric tuning, resonance with a signal is indicated by means of the
tuning indicator tube which operates on the cathode-ray principle. The strength of a received signal may be
determined by observing the size of the aperture appearing on the target of the tuning indicating tube, the
stronger a received signal the greater the reduction in the size of the aperture.
In order to obtain maximum performance on the Standard Broadcast Range ("A" Range) of these receiv¬
ers, a "signal admission control switch" is provided. This control is located on the inside rear flange of the
Fig. 1. Terminal Layout for Voltage Measurement Chart and Location of the
Aligning Adjustments for the R. F., I. F. and Discriminator Circuits.
P-28503 Form 2255 Issue 1 Printed in D. S. A.