RCA - VICTOR CO., INC.

MODAL 112 AC-DC 220V
Alignment, Parts List

220 Volt AC / DC Universal Receiver
Five - Tube Superheterodyne Table Model
SERVICE DATA

Electrical Specifications
Voltage Rating... 200 - 230 AC or DC
Frequency Rating (AC)... 50 - 60 Cycles
Power Consumption... AC 60 Cycles - 105 Watts - DC-85 Watts
Number and Types of Radiotron... 1 RCA-78, 1 RCA-6A7, 1 RCA-77, 1 RCA-43, 1 RCA-1273 - Total 5 Undistorted Output... 1.5 Watt
Frequency Rango... 540 KC - 1500 KC

This receiver is a five tube Super - Heterodyne designed to operate on AC or DC over the voltage and frequency range indicated. Features such as compact construction, dynamic speaker, single Pentode Output tube and the inherent sensitivity, selectivity and tone quality of the Super-Heterodyne are included in this instrument.

The circuit consists of a R.F. stage using Radiotron RCA-78, a combined oscillator and first detector using Radiotron 6A7, an I.F. transformer using two tuned circuits, a second detector using Radiotron RCA-77 and a power stage using Radiotron RCA-43. The rectifier is Radiotron RCA-12Z7 which is used in a half-wave circuit.

Line - Up Capacitor Adjustments
The line-up capacitor adjustments for the I.F. stage and for the R.F. circuits should be made in the following manner:
(a) Procure a modulated oscillator giving a signal at 175 KC and 1400 KC. An output meter and non-metallic screw driver are also necessary. The Stock No. 9050 test oscillator and Stock No. 7065 screw driver are suitable for this purpose. Figure C shows the location of the I.F. capacitors.
(b) The I.F. line-up capacitors should be first adjusted. This is done by placing the oscillator in operation at 175 KC, coupling its output between the control grid of the first detector and ground, connecting the output meter across the cone coil of the loudspeaker and adjusting the two I.F. line-up capacitors until maximum output is obtained.
(c) After the I.F. circuits are aligned, the R.F. and oscillator circuits are adjusted at 1400 K.C. Prior to making the adjustment however, the dial should be checked. This is done by making sure the dial indicator reads 530 when the tuning capacitor rotor plates are fully meshed with the stator plates. The adjustments are then made in similar manner as that of the I.F. except that the oscillator is set at 1400 K.C., its output is connected from antenna to ground of the receiver, and the dial is set to 140. The adjustment is made with the trimming capacitors located on top of the gang capacitor and each capacitor is adjusted for maximum output.

REPLACEMENT PARTS
Insist on genuine factory tested parts, which are readily identified and may be purchased from authorized dealers

RCA - VICTOR CO., INC.

MODEL 112 AC - DC 220V
Schematic, Voltage Trimmer locations

Figure C - Location of Line-up Capacitors

Figure A - Schematic Diagram

RADIOTRON SOCKET VOLTAGES
* Measured at 220 Volts A.C., 60 cycles (Maximum Volume Control)

RCA - VICTOR CO., INC.

MODEL 112 AC - DC 220V
Chassis wiring

Figure B - Wiring Diagram