Western electric 133 a schematic

Page 1

Wemrn Electric Company
No. | 33-A AMPLIFIER

Type
Two-stage push-pull amplifier for use as a line, isolation or 8 watt loud-
speaker amplifier in speech-input equipments, or sound systems.

Typical Electrical Characteristics

Gain-Approximately 47 db. maximum with 600 ohm input connection;
approximately 21.5 db with bridging input.

Operates From - 600 ohms, Nominal' impedance or high impedance
(20,000 ohms) bridging.

Operates Into - 600, 150, 30, 16, 7.5 or 1.75 ohms nominal impedance.

Output Power-Approximately 8 watts (+37 dbm)t with 2 per cent
total harmonic distortion.

Approximately 4 watts (+34 dbm) with 1 per cent har-
monic distortion.

Output Noise - Approximately -65 dbm Unweighted with maximum
gain approximately 70 dbm Unweighted with 5.2 db output pad
connected.

Frequency Characteristic - Flat within 1 db over the range 50 to 15,000
cycles.

Power Supply-Filament-6.3 Volts, 3 Amperes.

Plate-275 Volts, 66 ma

(Filament and plate supply may be obtained from ISA Rectifier.)

* (Ref.-.001 Watt)

Equipment Characteristics

Panel Size-Approximately 5% by 10% inches. The apparatus extends
approximately 5 inches from the front and 2 inches from the rear
of panel.

Weight-Approximately 61/2 pounds.

Mounting-Designed for mounting on a 177 Type Mounting Plate, which
requires 101/2 inches of relay rack space. Flexible rubber mountings
are furnished.

Instruction Bulletin No. 1040?

-l48*