^ rcaVictor TELEVISION RECEIVER MODEL Chassis No. KCS 721TS 26-1 (60 cycles) KCS 26-2 (50 cycles) Mfr. No. 274 , Service — Data 1947 No. T4 RADIO CORPORATION OF AMERICA RCA VICTOR DIVISION CAMDEN, N.)., U.S.A. Model 7 2 ITS Walnut or Mahogany GENERAL DESCRIPTION Model 721TS is a twenty-one tube, direct-viewing, table-model Television Receiver having a 10" picture tube (kinescope). The receiver is complete seven front-panel in one controls.
ELECTRICAL 72 ITS AND MECHANICAL SPECIFICATIONS PICTURE INTERMEDIATE FREQUENCIES (Continued) Horizontal (Picture Horizontal Hold) -i .Dual Control Knobs ' Picture Carrier Accompanying Frequency 25.75 Sound 21.25 Traps Mc Mc Vertical Picture (Picture Vertical Hold) J (Contrast) ..Dual Control Knobs Brightness (Brilliance) SOUND INTERMEDIATE FREQUENCIES NON-OPERATING CONTROLS Sound Carrier Frequency 21.
RECEIVER OPERATING INSTRUCTIONS The following adjustments are necessary when turning the receiver on ior the first time: Turn 1. volume "ON" receiver the control the SOUND desired channel. advance and Adjust the 8. Set 3. Turn the PICTURE the to hold control Adjust the PICTURE control 9. for suitable picture contrast. necessary some time, it may be FINE TUNING control slightly for improved sound fidelity. readjust the to counter- fully one Turn 4. BRIGHT- the .
INSTALLATION INSTRUCTIONS 721TS The Model 72 ITS television receiver is shipped complete in one carton except for the 10BP4 kinescope. The kinescope is shipped in a special carton and should not be unpacked until ready ior installation. — are worn. People not so equipped should be kept away while handling the kinescope. Keep the kinescope away from the body while handling. The shipping carton should be kept for use in case of future moves.
INSTALLATION INSTRUCTIONS the kinescope as lar forward as possible. Slide the kinescope cushion firmly up against the flare of the tube and Slide the deflection tighten the adjustment wing screws. yoke as far forward as possible. Connect the high voltage lead to the kinescope second anode socket. Slip C The antenna and power connections should now be made. Turn the power switch to control fully clockwise, and the "on" position, the brightness picture control counter-clockwise.
INSTALLATION INSTRUCTIONS 72 ITS (Continued) The stock #226 antenna is bi-directional on channels one through six (44 to 88 Mc). When used on these channels, the maximum signal is obtained when the antenna rods are broadside toward the transmitting antenna. The stock #225 antenna with reflector is unidirectional on channels one through six.
SERVICE SUGGESTIONS Some C troubles possible the of may that be encountered, no raster can of effect be caused by the following: (2) No adjustment assembly) being wrong value or open. These components are mounted SMALL RASTER high tubes and (8016) Check voltage. circuits.
ALIGNMENT PROCEDURE 721TS TEST EQUIPMENT recommended — To service this that the following test receiver properly, it is equipment be available: SERVICE PRECAUTIONS— Cutouts make possible to do it some without removing the chassis. Sweep Generator meeting R-F (a) the the following requirements: when Frequency ranges: 18 to 30 mc, 1 mc sweep width every mc sweep width If Output adjustable with at least (b) Output constant on (c) all .1 volt maximum.
ALIGNMENT PROCEDURE ORDER OF ALIGNMENT—When a necessary, is complete receiver alignment can be most conveniently periormed it the in following order: Sound Sound not exceed the specified values otherwise the response curve be broadened, permitting will Picture i-f Picture i-f on weak distortion signals.
ALIGNMENT PROCEDURE 721TS H-F AND CONVERTER Connect the minals. output, sweep sweep r-f the If shown connecting as Check channels 5 down through channel 1 by switching the receiver, sweep oscillator and marker oscillator to each channel and observing the response obtained. In all cases, the markers should be above the 70% response point. If this is not the case, Lll, L12, L37 and L38 should be retouched. On 9.
ALIGNMENT PROCEDURE Connect the signal generator method is same regardless inductance, frequencies necessary is it by adding obtained are align channel 13 to steps and first mately flat mately 90% If Set the receiver channel switch to channel 13. is to response. adjust- i-f response point. low frequency video response, of and of sync may occur.
ALIGNMENT TABLE 721TS THE DETAILED ALIGNMENT PROCEDURE BEGINNING ON PAGE 8 SHOULD BE READ BEFORE ALIGNMENT BY USE OF THE TABLES DISCRIMINATOR AND SOUND IF ALIGNMENT STEP No. IS ATTEMPTED.
ALIGNMENT TABLE THE DETAILED ALIGNMENT PROCEDURE BEGINNING ON PAGE 8 PICTURE IF STEP No. (Continued) SHOULD BE READ BEFORE ALIGNMENT BY USE OF THE TABLES AND TRAP ADJUSTMENT 72 ITS IS ATTEMPTED.
721TS ALIGNMENT TABLE THE DETAILED ALIGNMENT PROCEDURE BEGINNING ON PAGE R-F STEP No. 8 (Continued) SHOULD BE READ BEFORE ALIGNMENT BY USE OF THE TABLES AND CONVERTER LINE ALIGNMENT IS ATTEMPTED.
ALIGNMENT TABLE R-F STEP c No.
721TS CHASSIS VIEWS I T106 POWER TRANSFORMER Figure 21 — Chassis Top View (Showing Location of Major Components) 3 NOTE: IN Figure 22 SOME RECEIVERS.
WAVEFORM PHOTOGRAPHS Peak to peak voltages shown are nominal when 1 volt peak to peak video signal is 72 1 TS applied to Isl video amplifier (V105). c Video Signal Input to 1st Video Amplifier (At Pin 2 of V105) Figure 25 — Vertical (1.0 Volts, P to P) . 'P- ma > Figure 24 —Horizontal (1.0 Volts, P to P) ' ' S= ' i Output of (Pin Figure 25 — (5.
WAVEFORM PHOTOGRAPHS 72 ITS — Vertical Figure 35 (25 Volts, PtoP) Output of Integrating Network (Junction of R138 and C125) — 38 Plate of Output Tube (750 Volts, P to P) (Pin 5 of V107) Figure Vertical — 36 Grid of Oscillator Tube (175 Volts, P to P) (Pin 1 of VI 07) Figure (Continued) to P) (Junction of CI 29 — to P (65 Volts, Figure 39 Voltage Across Vertical Deflection Coils (L108, L109) (90 Volts, P to P) (At Green Lead of T103 — 37 Input to Vertical Output Tube Figure Vertical
CHASSIS WIRINQ DIAGRAM --11 " n I iT^ SE7J 'S' J MOTE ; t ' :^hzJ (^ o Li-:^ The Early production sets employed brightness and picture control #71784 in which the brightness is the outer knob end picture, the center knob. Late production, shown in the above wiring diagram employs control #73193 in which picture is the outer knob and brightness the center. front fected #72805 #73194 by is panel control decals are afthe control changes. Decal for control Decal #7 784. 1 #73193.
CHASSIS WmiNQ DIAGRAM 72 «E»-;i(eS--.»N.-_^ ^ ^~Jb1I9 to ion trap UlMiNEJ?-"^^ *«vJl f —f'o^l- The front panel control decats are affected #72805 #73194 by is is the control changes. for control #7 1 784. for control #73193. The operating instruction book fected by the control change. Book #49050-1 trol is for sets Decal Decol oiso afInstruction is employing con- Supplementary sheet #49050- S has been issued to convert -1 books for use with sets employing control #73193.
72 ITS -"- < ^ Direction of arrows clockwise rotation, 49050-15 has books for use 6^73193. Subproduction in- :iesignated as In early production receivers, an EM type of ion trap magnet was employed and was connected as shown by the dotted All voltages measure and with picture coni Voltages should hold 17 v. a-c supply. lines. 1 R196 was omitted in receivers employan EM tvpe magnet. R197 was employed only in receivers with the 247 -ohm focus coil. ing resistance vqIl Coil are not shown.
72 ITS SCHEMATIC DIAGRAM In early production receivers Qr\ EM type of ion trap magnet was employed and was connected as shown by the dotted ines. R196 was omitted ng an EM In some In I some n — Figure 50 codas, jR-F Unit 20 Wiring Diagram their in lug substitutions have component lead color receivers, changes In electrolytic capacitor values identification markings. and CH2 21 some is receivers employ- the antenna trap and C22) may be omitted.
SCHEMATIC DIAGRAM 721TS VI 14 6bA6 SOUND 15T. AM resistance values in ohms. All capacitance values and above in 1 MMF less K : than unless 1000. In some sets MF In some sets in 1 1-F R108 is connected to ~!4V. In used otherwise L122, R195 and R193 are All voltages ance of the focus lines. with the R195 was omitted ±20% with ing than ohm (L81, L82, C21 substitutions hove CI 42 component lead color Voltages should hold 7 v. a-c supply.
J REPLACEMENT PARTS 721TS STOCK STOCK DESCRIPTION No.
REPLACEMENT PARTS STOCK STOCK DESCRIPTION No. 71528 71429 71449 73233 71789 71521 Coil—Peaking coil Coil— Width control (1,122, R195) 71457 71437 71783 Cover— Insulating 72772 71510 Cover— Insulating 73193 72735 71440 71443 72734 71441 71785 14983 30648 30653 coil (L112) Coil coil (LI 13) Coil— Focus coil for electrolytics, for electrolytics, 72738 72739 30652 71452 72741 72773 71508 9914 72516 72927 31251 73249 71453 71775 71774 71416 RCA #71436 and #71782 cover for electrolytic.
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