'Emerson Radio SERVICE MANUAL MODELS 614-637-644-647 . MODEL 644 MODEL 614 MODEL 637 MODEL 647 Television Receivers -• EMERSON RADIO AND PHONOGRAPH CORPORATION 111 EIGHTH AVENUE NEW YORK 11r N.
Emerson Radio TABLE OF CONTENTS LIST OF TABLES Table Page Par. SECTION 1—GENERAL DESCRIPTION 1 2 Facilities Specifications 3 4 DESCRIPTION I Tube Complements II Receiver Characteristics III Adjustments Control Settings IV Generator Frequencies V Audio I-F Alignment VI Video I-F Alignment VII Tuner Alignment VIII Deflection Waveform Test Points Page _.._ .-.
Emerson Radio Section 1. GENERAL DESCRIPTION SYMBOL 1. FACILITIES—Emerson Models 614, 637, 644, and 647 are wide-band video receivers, providing dir eci-view high-definition pictures on ten or twelve-inch electro-magnetic deflection kinescopes. All models incorporate several design features including intercarrier sound, AFC in the horizontal sync circuits, automatic gain control, a series-type transformer power supply, and internal antennas.
Emerson Radio LOCATIONS b. RECEIVER CHARACTERISES: (Table I I ) . ITEM DESCRIPTION Voltage Rating 105-125 volts, 60 cycles a.c. Power Consumption All models— 190 watts Current Drain (At 117 volts a.c.) Frequency Range All' models — 1.7 amps. .Intermediate Frequencies Video — 25.75 MC. Audio — 4.5 MC. 54-88 MC.; 174-216 MC.
Emerson Radio 3. RECEIVER INSTALLATION — Locate the receiver where a minimum of bright light falls directly on the screen, although complete darkness is not recommended. Provide adequate ventilation by keeping the back of the receiver away from the wall. Do not obstruct the ventilating slots at the rear of the cabinet. All models are provided with a protective enclosure for the end of. the kinescope. The enclosure is fastened to the rear of the chassis.
Emerson Radio Figure 3-2—Test Pattern Correctly Adjusted Figure 3-4—Test Pattern Excessive Contrast Figure 3-3—Test Pattern Tuning Misadjusted Figure 3-5—Test Pattern Excessive Brightness I ,r' .,' V" '-f m_ .«.
Emerson Radio 6) Rotate the BRIGHTNESS control to the maximum counter-clockwise position and then adjust slowly clockwise until light is just visible on the screen. Rotate in reverse direction until light just vanishes. 7) Adjust the CONTRAST control until a picture appears on the screen and desired contrast is attained. A further reduction in the BRIGHTNESS control setting may improve the apparent contrast of the picture.
Emerson Radio 2. TUNER — The r-f. unit constitutes a separate sub-chassis of the receiver. This sub-chassis contains the r-f amplifier, converter, and oscillator stages. The channel switch, fine tuning control, tuned circuits, and first video i-f transformer are also contained on this chassis. Tuning and tracking adjustments for all twelve channels currently in use are provided.
Emerson Radio attenuate the audio i - f . An overcoupled i-f (T4) completes the amplifier stages and feeds the video detector (V4). The audio level is maintained just below the point of intertcrence with the video i-t. However, the audio i-t is not completely rejected, as the audio signal is recovered (ac the output ot the video detector) by heterodyning with the video i-f. The 4.5 me.
Emerson Radio of retrace of horizontal scanning, the field built up in the primary collapses and induces a highvoltage. This voltage is applied to the high-voltage rectifier (V18). From 8.5 to 10 kilovolts is produced by the power supply. The rectified voltage is filtered by C63 and R89, and applied to the second anode of the kinescope. Chassis 120113B differs from Chassis 1201 IB in that C63 is returned to B—, instead of the plate of VI9. b.
Emerson Radio -, C3 Figure 5-1—Deflection Yoke and focus Coil Adjustments, Combined Mechanical and Electrical Centering a. DEFLECTION YOKE: If the raster lines are not horizontal, loosen the center wingnut (Al) and rotate the yoke coil assembly to correct the condition. Tighten the wingnut firmly. The position of the assembly along the axis of the kinescope is fixed by the two outer wingnuts (Bl, B2). The yoke should be positioned approximately at the center of the slots.
Emerson Radio Figure 5-3—Schematic Diagr
Emerson Radio PART No.
Emerson Radio Proper adjustment of the HORIZONTAL and VERTICAL LINEARITY controls, and the SIZE controls should result in test patterns in which the circles are round and the wedges are linear and equal. The test pattern circles should be concentric with the curved sides of the mask. 955282 120 TO TO 50 GEN. / OR HORZONTALLY IN FRONT OPENING , ADJUST THE LEVER EXTEND NG FROM BACK COVER. H V PICTURE CAN LEVER --'' i*T"~""|^H>. S? |H^'-'JT"''*1 11 ! 1 I
Emerson Radio figure 5-7—Location of Alignment Points AUDIO I-F ALIGNMENT: (Table V). SIGNAL GENERATOR INPUT CONNECTION FREQUENCY MEASURING INSTRUMENT ADJUST PROCEDURE 1 Marker generator through .OO1 mfd. to pin 2 of V4. Low aide to B—. Marker—4.5 MC. Connect v.t.v.m. Connect v.t.v.m. to junction of R38 and C27. Low side to B—. C79 Peak for maximum response. Adjust generator input to produce one volt reading on v.t.v.m. 2 n Marker—4.5 MC.
Emerson Radio VIDEO I-F ALIGNMENT: (Table V I ) . STEP 1 2 3 SIGNAI GENER ATOR INPUT CONNECTION FREQUENCY Lightly couple Sweep- 23.5 MC Connect vertical marker gen. to input of scope (10 MC. sweep) through 10K repin 1 of V3: Marker-25.75 Sweep gen. from sistor to junction MC. pin 1 to chassis, of Ll, R16, and C16. Low :hrough .001 mfd. side to chassis. Connect marker Sweep -23. SMC. and sweep gener- (10 MC. sweep) Marker-25.25 ators to pin 1 MC. of V2, through .001 mfd. Low side to chassis.
Emerson Radio TUNER ALIGNMENT: (Table V I I ) . STEP 1 SIGNAL GENERATOR INPUT SWEEP GEN. MAR. GEN. 209.75 MC. 207.0 MC. 2 » 3 213.0 201.0 195.0 189.0 183.0 177.0 85.0 79.0 69.0 63.0 57.0 4 5 6 7 8 9 10 11 12 13 ft MC. MC. MC MC. MC. MC. MC. MC. MC. MC. MC. 215.75 203.75 197.75 191.75 185.75 179.75 87.75 81.75 71.75 65.75 59.75 MC. MC. MC. MC. MC. MC. MC. MC. MC. MC. MC. CHANNEL ADJUST PROCEDURE 12 A12 12 A14, A15, A16 Adjust for placement of 21.25 MC.
Emerson Radio ALL VOLTAGE AND RESISTANCE MEASUREMENTS MADE TO B- ( R - 6 1 ) Figure 5-10—Voltage and Resistance Diagram DEFLECTION WAVEFORMS: (Table VIII). TUBfi Sync Separator V-15A First Synci Amp. V-15B Second Sync. Amp. V-6B Hor. Phase Inv. V-11A Phase Det. V-12 Hor. Control V-11B Hor. Osc. V-13 Vert. Osc. V-14 Vert. Output V-16 18 TEST POINT Pin 3 Pin 1 Pin 6 HORIZONTAL KEY PEAK to PEAK LETTER VOLTAGE AH 22.3 BH 8.9 CH 11.4 VERTICAL KEY PEAK to PEAK LETTER VOLTAGE AV 36.6 BV 11.3 CV 18.
Emerson Radio Figure 5-11—Deflection a. b. c. CODE MARKING — E: Part No. 925162, C21, C36, and C49; C49 (80 mfd.) is marked A, and C21 (10 mfd.) is marked Q due to incorrect condenser marking, instead of markings shown on schematic diagram. CODE MARKING — C: No Pyramid paper tubular condensers used. CODE MARKING-TRIANGLE 1: Revisions to correct picture flicker. 1) Removed red lead from B+ 125-volt point on terminal strip near fourth i-f and from pin 6 of V-5 (6AC6). Removed red lead from the 40 mfd.
Emerson Radio 1) Added a single lug terminal strip between sockets V-l and V-ll. 2) Transferred junction of R-66 (4.7K), R-67 (2.2K), and C-53 (.001 mfd. mica) from dummy lug under vertical output transformer to new dummy lug terminal. 3) Transferred wiring from lug 8 of VI1 socket to the empty lug on terminal strip under vertical output transformer. 4) Removed jumper wire connecting lugs 3 and 4 of V-6 socket.
Emerson Radio 11. SECONDARY AREA RECEPTION — Noise conditions in secondary areas of signal reception (fringe areas), or in areas where noise is excessive compared to signal level, give rise to problems of sync stability. For such areas only, the following simple changes should be made in the circuit. References are lo the schematic diagram. T-9-, C-64-, T-8 a. Remove end of R8 connected to CIO and the AGC bus; reconnect to chassis. b.
Emerson Radio 13. PARTS LIST — Chassis 120110B, 120113B. SYMBOL PART NO. C-4 C-5 928006 928006 928006 928109 928006 910015 928006 928006 910015 9280O6 928006 910290 923062 928006 j 923062 ot (922025 923062 923064 925161 923061 923062 910130 928006 928006 910031 928006 925161 910010 923079 923061 923061 j 923062 or [922025 925162 923078 922101 Pt. of C-21 Pt. of C-29 Pt. of C-21 P.t. of C-29 928006 923067 923064 910028 910029 928006 Pt. of C-36 910027 923068 923080 910027 j 923062 or 1922025 910010 Pt.
Emerson Radio PARTS LIST — Chassis 120110B, 120113 B. (cont.) 6 SYMBOL PART NO.
Radio and Television
CABLE RADIO ADDRESS AND EMPHONOCO NEW YORK PHONOGRAPH 111 EIGHTH AVENUE §™"J CODES: BENTLEYS ABC CORPORATION NEW Y O R K C | T Y ]] January 30,1950 TO ALL aiERSON TEI£VISIQN DISTRIBUTORS i Field Service Bulletin #5 Subject: Changes in Model 6U8 Chassis 120110E Chassis coded with Triangle 1 incorporate the following changes to improve vertical linearity* 1. R98 changed to 1 Beg. \. 2.
IE CHELSEA 2-lfloO CABLE A D D R E S S . EMPHONOCO NEW YORK CODES B E N T L t Y S ABC 5TH EDITluN I mP Tftnerson RADIO AND PHONOGRAPH 111 EIGHTH AVENUE If A CORPORATION 1 NEW YORK CITY, 1 1 December 28, 1949 TO ALL EMERSON TELEVISION DISTRIBUTORSt Field Service Bulletin #1 Subject! ict Revision to eliminate picture flutter caused by line voltage variatj on. f Models 614C, 637C, 644C, 647C using chassis 1201 IOC and 120113C having triangle codes 1 and 2.
HONE CHELSEA 2.ISOO CABLE A D D R E S S . EMPHONOCO NEW YORK COOES BENTLEYS ABC 5TM 'EDITION Jynerson RADIO AND PHONOGRAPH 111 EIGHTH AVENUE ff CORPORATION \W Y O R K CITY, 1 1 September 13, I9k9 TO ALL EMERSON DISTRIBUTORS; In order to keep you advised of circuit changes in Emerson Television Receivers, a simple code identifying system has been put into effect. A triangle with a number inside it will be inked on the rear wall of the chassis next to the AC power input.
"Emerson Radio ADDENDUM SERVICE NOTE TELEVISION RECEIVERS MODELS 614, 637, 644, and 647 CHASSIS MODELS 1201 IOC and 1201 I3C I. GENERAL The mode's listed have been revised both mechanically and electrically. The major mechanical change is the conversion to two dual-controls in plnce of the original arrangement of four dual-controls. Such models and chassis are identified by the subscript C or BC, as for example Model 644C.
SOUND - I f V-7 »Mf> 6AU6 SOUND DIS » AUDIO A SOUND - I F L I W I T E R V-8 6AU6 V-9 BUILT-IN DIPOLE «NT. r/i;.
SOUND DISCR AUDIO AMI-. CHASSIS NO. I Z O I I 3 - C \-VERT.MOLO '—VERT, LINEARITy PART NO.
Fig. 4—Automatic Tuner—Part No. 470605 6. PICTURE TEAR Code markings, Triangle 8, on B series chassis, and Triangle 1 on C series chassis refer to the same circuit modifications to eliminate picture tear. These markings include all previous revisions, plus the following circuit changes: 7. a. Removed R-27 (33K, 1 watt). b. Connected pin 6 of V-5 (screen) directly to B-j- (output side of filter choke connected to C-41, 40 mfd., marked Q). c. Replaced R-25 (220K) with 1 megohm, l/z watt resistor.
HELSCA 2-ISOO CABLE ADORE**: EMPHONOCO NEW YORK COOES: BENTLETS ABC STM EDITION I 'Emerson RADIO AND PHONOGRAPH 111 EIGHTH AVENUE CORPORATION NEW Y O R K C I T Y , 11 December 16, 1949 Additions to Service Han.ual. Section 10. Production Changes HOB & 113B Chassis Triangle 6 Identifying receivers with built-in antenna, improved mechanical focus with wobble plate and included are revisions issued under Code notices Triangle 4 and Triangle 1, 1.
