5. Adjusting Antenna Compensating Condenser
This adjustment should only be made after the receiver has been properly installed in the car with the antenna connected to the receiver. Tune the receiver to a weak signal at the high frequency end of the broadcast band at about 1200 K.C. and with the antenna fully extended, adjust the antenna compensating trimmer (Illus. L, Fig. 6) for maximum signal strength.
Do not attempt to make any other alignment adjustments with the receiver installed in the car.

(a) Remove speaker (front) cover, rear cover and the bottom of tuner section. Unsolder the connecting leads from the volume control and other points in the chassis.
(b) Remove the link and arm arrangement that operates the band switches by first removing the two units, (A), holding the short link arm (B) to the band indicator shaft.
(c) Remove screws (C) and link arms (D) from each of the band switch shafts, but in removing the center one, care should be taken not to lose the two steel rollers and "S". spring (which are loose on the assembly) from the detent device at the base of the center coil unit.
(d) Remove the four units (B) which hold the coil plate (F) to the tuner assembly and withdraw the coil plate from the assembly, being careful to prevent the coil cores from striking any part of the assembly which may result in breakage of the core.
(e) After removing the two small screws located at the base of each coil unit, the coil units can then be removed from the coil plate. In re-assembling the cores into the coil units, hold the coil plate (F) slightly " off-square " from the cores, then insert the core nearest its coil, one by one, as the coil plate is brought square with the tuner assembly frame.

REMOVAL OF COIL UNIT
Should it become necessary to remove a coil unit, the following procedure should be followed:

Adjust trimmer G to match car antenna (1430 XC) when radio is installed.

Rock gang condenser back and forth through signal during 600 K.C. adjustment of screws H & J. See Bulletin 6D-2 for complete Alignment Procedure.

PUSH BUTTON SET - UP

Release holding spring in bottom of button, pull button off. Loosen re-set screw, tune in desired station. Push in re-set screw until it bottom. Release and tighten screw. Replace button.

Voltage readings taken between socket terminals and ground with D.C. voltmeter having Res of 1000 ohms per volt. All readings taken with 6.0 volts across heaters. Current drain with dial light 6.4 amps. "B" supply drain 63 m.A. tolerances on voltages +/- 10%

Fig. 1 - Tube Socket Voltages

Fig. 5 - Parts Layout - Tuner

Fig. 2 - Buick Model 1323457 Circuit Diagram

GENERAL: The Buick model 1323457 is a 7 tube three unit radio built especially for 1941 Buick cars. It is arranged with an arm rest mounting tuner, and amplifier unit for trunk mounting and a header speaker to be mounted in the rear of the car.

TUNING CONTROL: Tuning is accomplished by means of a manual tuning control or by means of five push buttons each of which adjusts the position of three iron cores in the tuning unit to preselected frequencies.

Setting up the push buttons for any desired station is accomplished by pressing the button into its latched position and rotating in the manner No of a manual tuning control until the desired station is tuned in. locking device is required to retain this setting.

Note: Do not hold button in beyond its normal latching position when setting up station.

The manual control operates by pressing the tuning knob into its latched position and tuning in the conventional manner.

Fig. 4 - Parts Layout - Bottom View

Fig. 3 - Parts Layout - Top View

TUNING CONTROL: Tuning is accomplished by means of a manual tuning control or by means of five push buttons each of which adjusts the position of three iron cores in the tuning unit to preselected frequencies.

Setting up the push buttons for any desired station is accomplished by pressing the button into its latched position and rotating in the manner No of a manual tuning control until the desired station is tuned in. locking device is required to retain this setting.

Note: Do not hold button in beyond its normal latching position when setting up station.

The manual control operates by pressing the tuning knob into its latched position and tuning in the conventional manner.

CIRCUIT ALIGNMENT

If realignment is found necessary, the circuits can be properly aligned only with the use of a calibrated test oscillator or signal generator and an output meter. Extreme care should be exercised in following the alignment instructions in order to obtain the best performance possible.

ALIGNMENT PROCEDURE

Two separate alignment procedures are included in these instructions. The first or capacity alignment is to be considered the usual alignment procedure and the second or capacity and inductance alignment is to be used only when there is definite evidence that the iron cores of the tuning coils are out of alignment.

CAPACITY ALIGNMENT

1. Aligning I.F. stages at 455 K.C.

(a) Connect the ground lead of the signal generator to the chassis frame.

(b) Connect the signal lead of the signal generator to the grid of the 788 tube (Grid side of condenser 12) through a 0.1 mfd. condenser.

(c) Connect an output meter across the speaker voice coil. (If speaker is disconnected a 4 ohm load may be used instead.)

(d) Set signal generator to. 455 K.C.

(e) Turn the set volume control on full and tune the set to a position where no squeals or beat notes may be heard, and so that when the tuning control knob is rotated within narrow limits there is no appreciable change in output. The tone control should be rotated to its extreme high position (clockwise.)

(f) Adjust the I.F. trimmers (Illus. A, B, C, D, Fig. 3) and the I.F. core adjustment (Illus. E, Fig. 4) until maximum output is obtained.

(g) Repeat these adjustments with as low an output from the signal generator as possible for more accurate alignment.

(h) Connect the signal generator to the antenna connection of the set through an 80 mmfd. condenser.

(i) Adjust the I.F. trap adjustment (Illus. M, Fig. 3) for MINIMUM output.

2. Alignment at 1560 K.C.

(a) Leave signal generator connected the same as for the I.F. trap adjustment.

(b) Tune the set to the extreme high frequency position against the stop.

(c) Set the signal generator to 1560 K.C.

(d) Adjust the oscillator trimmer (Illus. F, Fig. 5) for maximum output.

3. Alignment at 600 K.c.

(a) Set the signal generator to 600 K.C. and tune the set to this signal.

(b) Adjust the R.F. trimmer (Illus. G, Fig. 5) and the antenna trimmer (Illus. H, Fig. 5) for maximum output.

Capacity Alignment

1. Aligning I.F. stages at 455 K.C.

(a) Connect the ground lead of the signal generator to the chassis frame.

(b) Connect the signal lead of the signal generator to the grid of the 7B8 tube (Grid side of condenser 12) through a 0.1 mfd. condenser

2. Mechanical alignment of cores -- Cont'd

(b) Remove the pointer plate (note insulating washers under mounting screw) without disturbing the tuning mechanism.

(c) Using a spare core as a gauge, adjust the oscillator core K so that its rear surface is exactly flush with the front end of the oscillator coil winding.

(d) Manually tune the et to a point where the front surface of the oscillator core is flush with the front end of the oscillator coil fiber mounting bushing.

(e) Adjust the antenna and R.F. cores (Illus. J, L, Fig. 5) so that the front surfaces of these cores are flush with the front ends of the coil fiber mounting bushing. Paragraphs (c), (d) and (e) mechanically align the cores so that all three are just at the point of entering their respective windings when the tuning mechanism is against the high frequency stop.

(f) Replace the pointer plate assembly.

3. Aligning at 1560 K.C.

(a) Connect the signal lead of the signal generator to the antenna connection of the receiver through an .000075 mfd. condenser.

(b) Turn the manual control of the set to the high frequency end against stop.
(c) Set signal generator to 1560 K.C.
(d) Adjust the oscillator trimmer (Illus. F, Fig. 5) for maximum output.

4. Aligning at 600 K.C.

(a) Leave the signal generator connected the same as before and set frequency to 600 K.C.

(b) Tune in this frequency on the set.

(c) Adjust the R.F. trimmer (Illus. G, Fig. 5) for maximum output.

(d) Adjust the antenna trimmer (Illus. H, Fig. 5) for maximum output.

5. Aligning at 1400 K.C.

(a) Set the signal generator to 1400 K.C. and tune set to this signal.

(b) Adjust the antenna core (Illus. J, Fig. 5) and the R.F. core (Illus. L, Fig. 5) for maximum output.

6. Realigning at 600 and 1400 K.C.

(a) Repeat the alignment outlined under paragraphs 4 and 5 with as low an output from the signal generator as possible.

(b) Apply cement to the core screws to prevent their changing alignment.

7. Adjusting receiver to car antenna

After the receiver is installed in the car readjust the antenna trimmer (Illus. H, Fig. 5) on a weak station near 1400 K.