Tektronix 491 Maintenance Manual
  1. Manuals
  2. Brands
  3. Tektronix Manuals
  4. Measuring Instruments
  5. 491
  6. Maintenance manual
Tektronix 491 Maintenance Manual

Tektronix 491 Maintenance Manual

Spectrum analyzer
Hide thumbs Also See for 491:
Table of Contents

Advertisement

Quick Links

TM 9-6625-2467-15
D E P A R T M E N T
O F
T H E
A R M Y
T E C H N I C A L
M A N U A L
OPERATOR'S, ORGANIZATIONAL, DIRECT SUPPORT, GENERAL SUPPORT,
AND DEPOT MAINTENANCE MANUAL
(INCLUDING REPAIR PARTS)
SPECTRUM ANALYZER
(TEKTRONIX, INC. MODEL 491)
(6625-494-2937)
D E P A R T M E N T
O F
T H E
A R M Y
H E A D Q U A R T E R S ,
DECEMBER 1969

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the 491 and is the answer not in the manual?

Questions and answers

Related Manuals for Tektronix 491

Summary of Contents for Tektronix 491

  • Page 1 OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, GENERAL SUPPORT, AND DEPOT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS) SPECTRUM ANALYZER (TEKTRONIX, INC. MODEL 491) (6625-494-2937) H E A D Q U A R T E R S , D E P A R T M E N T...
  • Page 2 WARNING HIGH VOLTAGE is used in the operation of this equipment. DEATH ON CONTACT may result if personnel fail to observe safety precautions. Learn the areas containing high voltage in each piece of equipment. Be careful not to contact high-voltage or 115-volt ac input connections when installing or operating this equipment.
  • Page 3 TEKTRONIX, Inc. TM 9-6625-2467-15 TECHNICAL MANUAL HEADQUARTERS DEPARTMENT OF THE ARMY No. 9-6625-2467-15 ) Washington, D.C., 15 December 1969 SPECTRUM ANALYZER (TEKTRONIX, INC. MODEL 491) (6625-494-2937) CONTENTS Section 1 Characteristics Section 2 Operating Instructions Section 3...
  • Page 4 Spectrum Analyzer. Fig. 1-1. The Type 491...
  • Page 5 SECTION 1 CHARACTERISTICS The Type 491 Spectrum Analyzer is a wide band, general purpose portable spectrum analyzer with an RF center frequency range from 10 MHz to 40 GHz. The ana- lyzer displays signal amplitude as a function of frequency...
  • Page 6 ELECTRICAL CHARACTERISTICS (cont) Characteristic Performance Requirement S u p p l e m e n t a l I n f o r m a t i o n Dispersion M H z / D I V R A N G E Range .2 MHz/Div to 10 MHz/Div In a 1-2-5 seauence...
  • Page 7 TIME BASE Performance Requirement S u p p l e m e n t a l I n f o r m a t i o n Characteristic Rear panel connector RECORDER Output mV per displayed division amplitude of signal in LIN made. µs/div to 0.5 s/div In a 1, 2, 5 sequence...
  • Page 8 Characteristic Performance Requirement S u p p l e m e n t a l I n f o r m a t i o n Temperature Automatic resetting thermal cutout protects Operating – 1 5 ° C t o + 5 5 ° C instrument from overheating.

  • Page 9: Operating Instructions

    The Type 491 is selectors. designed to provide a spectral display of the frequency distribution of electromagnetic energy within the frequency range of 10 MHz to 40 GHz.
  • Page 10 Fig. 2-2. Handle positioned to provide a stand for the instrument. C A U T I O N T h e T y p e 4 9 1 s h o u l d n o t b e o p e r a t e d w i t h t h e s e v o l t a g e s e l e c t o r s w i t c h e s i n i m p r o p e r p o s i t i o n s .
  • Page 11 Center frequency (radio frequency or intermediate fre- incidental frequency modulation when limited by “incidental quency)-That frequency which corresponds to the center frequency modulation” (in units of Hz). of the reference coordinate. Phase Lock-The frequency synchronization of the local Center frequency range (radio frequency)-That range of oscillator with a stable reference frequency.
  • Page 12 INTENSIFIER-Controls the relative brightness between the plays on the CRT that are not tunable with the RF center fre- displayed signal and the trace baseline. quency controls. POSITION-TWO (2) controls that position the CRT beam 2. Image response-The superheterodyne process results in the vertical and horizontal plane.
  • Page 13 (between the local oscillator and reference frequency) to the vertical display system. POWER-Turns power off and on to the Type 491. Provides a visual indication to the operator of phase lock INDICATOR LIGHT-indicates when POWER is applied to operation.
  • Page 14 S A W O U T - A 7 0 t o 9 0 m V s a w t o o t h s i g n a l o u t p u t t h a t is coincident with the analyzer sweep. 3. Connect the Type 491 to a suitable power source and RECORDER-Signals on the display may be recorded by turn the POWER switch to ON.
  • Page 15 12. Tune the signal to the extreme left graticule line with GENERAL OPERATING INFORMATION the RF CENTER FREQUENCY control. Note the dial reading. Light Filters Tune the signal to the extreme right graticule line and note the dial reading. The difference between dial readings is The instrument is shipped with a mesh filter installed.
  • Page 16 See Fig. 2-6. Signal Application The application of any RF signal to the Type 491 is deter- mined by its frequency and level. Signals between 10 MHz and 275 MHz are applied to the Band A, BNC connector.
  • Page 17 Signal input power to the analyzer should not exceed -30 dBm. Signal above this level will overload the 1st mixer and/ or the 1st IF stage and generate spurious signals on the dis- play. Add at least 10 dB of attenuation to the input when the signal begins to compress (no increase of signal amplitude with an increase of signal level).
  • Page 18 analyzer sweep rate is increased, the amplitude Mixer Peaking of the signal will decrease and the bandwidth becomes The MIXER PEAKING control has a switch and variable wider; which signifies that both the sensitivity and resolution control position and is used to optimize mixer conversion in have been degraded by the analyzer sweep rate, the harmonic bands of Band C.
  • Page 19 d . W i t h t h e D I S P E R S I O N R A N G E i n t h e M H z / D I V p o s i - tion, adjust the IF CENTER FREQ-CAL for minimum signal shift as the DISPERSION is switched through the MHz (10 MHz - .2 MHz) positions.
  • Page 20 Fig. 2-10. 1 MHz MARKERS OUT (Phase lock reference) connector. D I S P E R S I O N 1 M H z / d i v . d . A d j u s t t h e D I S P E R S I O N - C A L f o r 1 m a r k e r / d i v i s i o n . Use the Horizontal POSITION control or the IF CENTER FREQ control to align the markers to the graticule lines.
  • Page 21 TIME/DIV selector settings. In some applications, particularly at 0 dispersion, or when slaving the Type 491 to a recorder, it may be desirable or necessary to trigger the display. The Type 491 may be trig- gered from the following three sources: INT, LINE and EXT.
  • Page 22 Fig. 2-15. Adjusting FINE RF CENTER FREQ control for phase lock operation. F i g . 2 - 1 4 . T o t r i g g e r t h e a n a l y z e r f r o m t h e d i s p l a y r e q u i r e s 0 . 2 When searching a frequency band, set the MIXER PEAK- d i v i s i o n s o f s i g n a l .
  • Page 23 erence level of the output amplifier. This DC level changes as the FINE RF CENTER FREQ control is rotated and shifts the local oscillator frequency a slight amount. It also affects the vertical position of the display baseline. Thus, by de- pressing the LOCK CHECK button and slowly turning the FINE RF CENTER FREQ control (Fig.
  • Page 25 Fig. 2-17 is a control setup chart for the front panel of the measure the sideband energy distribution and modulation Type 491. This figure may be reproduced and used as a test bandwidth. setup record for special applications or procedures. It may also serve as a training aid to facilitate control operation.
  • Page 26 Pulse Modulated Signal Spectrum When a CW signal is pulse modulated, the carrier is per- iodically turned on and off. The on period is determined by the modulating pulse width, the off periods is related to the pulse repetition rate or frequency. The carrier is usually modulated with rectangular shaped pulses.
  • Page 27 2. True responses move across the dispersion window from signals are called spurious responses. See spurious responses left to right, on the Type 491, as the RF CENTER FREQUENCY under Spectrum Analyzer Terms at the beginning of this sec- is increased, or in the same direction as the tuning knob tion.
  • Page 28 Fig. 2-23. Frequency difference measurement between two signals. cillator fundamental. If an incorrect dial scale is used to measure the frequency movement of the signal, as the RF CENTER FREQUENCY is tuned, an erroneous reading will be obtained, This erroneous reading however can be used to identify which scale to use to obtain the corect frequency r e a d i n g .

  • Page 29: Frequency Measurements

    5. Read the frequency indicated on the RF CENTER FRE- The following are basic applications for the Type 491 and are presented to illustrate some of these uses in the Q U E N C Y d i a l . T h e s i g n a l f r e q u e n c y i s t h e d i a l r e a d i n g ±...
  • Page 30 Frequency Stability by this process, since the amount and direction of the drift may be graphically indicated by photographs. The Type 491 con be used to measure long and short term frequency stability, when the local oscillator is phase Amplitude Modulation locked to a stable crystal-controlled reference frequency.
  • Page 31 Over modulation will produce extra sideband frequencies. The spectrum is very similar to multi-frequency modulation. Over modulation, however, is usually distinguished from the multi-frequency modulation by: 1) The spacing between over- modulated sidebands is equal, while, multi-frequency side- bands may be arbitrarily spaced, unless the modulating fre- quencies are harmonically related;...
  • Page 32 See Fig. 2-14. The Type 491 requires a 0.2 to measure the pulse width of the pulse modulated spectrum.
  • Page 33 This stabilizes the local oscillator frequency and permits narrow 1 kHz/div dispersion settings. A block diagram of the Type 491 is shown in Fig. 3-1 and the Diagrams section. Signals within the frequency range of the Type 491 that...
  • Page 35 Band B: The oscillator for band B is similar to band A If the local oscillator is slowly tuned through a frequency oscillator. The fundamental frequency range 470 MHz to 1100 range, signals above the specified sensitivity level will appear MHz and the 2nd harmonic of the oscillator is used for the above the noise when they reach this optimum point.
  • Page 36 D1134 and D1139. When the charge has The back bias across D1116 is controlled by INT REF FREQ charge of diodes dissipated, the diodes generate a fast recovery step. This control R1106. This change in back bias increases or de- recovery step is differentiated and coupled through trans- creases the diode capacity and shifts the resonant frequency mission line transformer T1140, T1150 and T1160 to the phase...
  • Page 37 CHECK switch to the vertical deflection system. At zero beat, Sweeper Circuit the output signal amplitude snaps to a minimum and the cir- This circuit (see Fig. 3-5) provides a swept frequency, cuit locks the local oscillator to the reference frequency by centered at 275 MHz, to the wide band mixer amplifier.
  • Page 38 resultant feedback signal from a frequency to voltage con- Output signal from the oscillator is tapped across the verter and ramp generator. Any differential between the partial winding of L314 and capacitively coupled to trans- two signals is a voltage output that controls the bias on formers T330 and T331.
  • Page 39 transmission line input impedance increases, the open ended line input impedance decreases. This produces proportionate changes to the output signal from the diodes. Signal output from diode D376 becomes more negative, and signal output from D373 becomes less negative. This push-pull drive is applied to the comparator Q260 and converted to a single ended output signal for the sweep comparator.
  • Page 40 All of the adjustments interact and Diodes D277 and D279 isolate the narrow band discrimi- are adjusted for optimum response flatness over the pass nator tuned circuit when the Type 491 is operating in the band. MHz/DIV dispersion range. They prevent parasitic oscillation...
  • Page 41 its base to emitter Q420. A feedback winding on T424, to is tuned to 5 MHz and couples the signal to the 5 MHz IF the hose of Q420, provides the neutralization far the col- amplifier Q460. Diode D454 in the collector load of Q450 lector-to-base capacitance.
  • Page 42 Fig. 3-10. Block diagram of the video detector and vertical amplifier. 3 - 1 0...
  • Page 43 Video Detector and Vertical Amplifier (Fig. 3-10) Variable Resolution Amplifier T h e v a r i a b l e r e s o l u t i o n a m p l i f i e r i s d e s i g n e d t o v a r y The 5 MHz IF response from the variable resolution am- plifier is applied to a band-pass filter circuit to shape the the bandwidth of the 5 MHz IF from approximately 100 kHz...
  • Page 44 The input signal is attenuated through R617 and the input R672 (Vert Gain adjustment) in series with R671, to the impedance to Q620, so that an approximate 5 division dis- emitter of Q660. Gain of the amplifier is a function of the p l a y i n t h e L I N p o s i t i o n w i l l p r o v i d e a p p r o x i m a t e l y t h e ratio R is controlled by the Vert Gain adjustment.
  • Page 45 circuit. Triggering becomes a funtion of the trigger signal When the emitter voltage of Q752 steps up, Q771 is turned amplitude and the slope of the trigger signal. on hard. This applies forward bias to the disconnect diode, and timing current plus extra base current is now supplied The Trig Level Centering R724 is adjusted with the Trigger by Q771.
  • Page 46 R1032 (Intensity Range) and R1033 (INTENSITY level con- trol) provide a range from 0 to approximately 100 volts The low voltage power supply in the Type 491 (see Power bias for the CRT to vary the CRT beam current. FOCUS...
  • Page 47 Overload protection is provided by fuse F900 ond F902. +10 Volt Supply and Regulator. Error sensing far the Thermal cutout TK902 in the primary circuit of T900 opens +10 volt supply is accomplished by the amplifier Q930. the transformer primary circuit if the temperature inside the A sample of the +10volt supply is applied from the voltage analyzer rises above a safe level.
  • Page 49 ( s u c h a s K e l i t e o r S p r a y W h i t e ) . A b r a s i v e c l e a n e r s should not be used. This section of the manual pertains to the maintenance and troubleshooting of the Type 491. The first portion of C A U T I O N the section describes some general preventive measures to Do not permit water to get inside controls or shaft help minimize major problems.
  • Page 50 . mic oiler (Tektronix Part No. 003-0280-00) and apply no more than one drop to each point.
  • Page 51 Table 4-2 shows the wiring color shown in Fig. 4-1. code for the power supply voltages used in the Type 491. The color coding helps trace a wire from one point in the instrument to another.
  • Page 52 the pin connectors. If the connectors are grasped near the ponent can then be correctly soldered in its place, Observe wire end by a pair of needle nose pliers, their removal soldering precautions and techniques as described in Solder- or installation is relatively easy. ing Techniques later in this section.
  • Page 53 Fig. 4-4. Power Supply Circuit board assembly with wiring color code.
  • Page 54 Fig. 4-5. Horizontal Display circuit board assembly showing color code to pin connectors.
  • Page 55 Fig. 4-6. IF Control board assembly. Wiring color code to pin connector.
  • Page 56 F i g . 4 - 7 . H o n e y c o m b a s s e m b l y a n d w i r e c o l o r c o d e t o t h e p i n connector. 3. Turn the Type 491 on its side (see Fig. 4-11). Remove the nylon rocker arm from the DISPERSION RANGE switch SW365.
  • Page 57 Fig. 4-9. Phase lock assembly and wiring color code to the pin connector. To replace the CRT, reverse the removal procedure. Make certain the faceplate of the CRT seats properly against the front panel. It may be necessary to loosen the two side screws at the side of the tube clamp and realign the tube base.
  • Page 58 Fig. 4-11. Honeycomb assembly open and ready for voltage and waveform measurements. back 5. Lift the switch assembly up so the studs clear the mount- 4. Loosen the two nuts that secure the of the switch ing bracket, then slide the assembly back and out of the assembly to the rear mounting bracket.
  • Page 59 Fig. 4-14. Dispersion range switch removal. Replacement of these switches or the control is the reverse of the removal procedure. Replacing the Pilot Light Unscrew the colored pilot light cover. Pull out the bulb and replace. Removing the Cover to the Phase Lock Assembly (Fig.
  • Page 60 Removing the Circuit Board Assembly for the Phase Lock (See Fig. 4-16) 1. Remove the retainer nuts on the connectors J1140, J1150 and J1160. 2. Remove the two screws that secure the pin connector to the chassis, 3. Unsolder the wires to the INT FREQ control and remove potentiometer.
  • Page 61 Fig. 4-16. Removing the phase-lock assembly board. 3. Band C Mixer Diodes 1. Band A Mixer Diodes a. Coaxial Mixer. Unscrew the base of the coaxial mixer. a. Disconnect the sub-miniature connectors, remove the Fig. 4-18C. Replace the diode and re-assemble the mixer. two mounting screws and the mixer assembly.
  • Page 62 Fig. 4-17. Preparation to remove the oscillator and tuner assembly. b. Slide the oscillator tube out of the mounting flanges by gently pushing the tube with a plastic or fiber dowel. See Fig. 4-19B. c. Insert the new tube and slide into place. Do not bend the two contact fingers for the filament buttons.
  • Page 63 Fig. 4-19. Band A and B local oscillator assemblies. Replacing Components on the Circuit Boards 3. When the lead comes out of the board it should leave a clean hole. If not, the hole should be cleaned by reheating It is best to remove the circuit board assembly to replace the solder and placing a sharp object such as a wooden components, because melted solder at the connections will toothpick or enameled wire into the hole to remove the old...
  • Page 64 Fig. 4-20A. Tube subassembly removal procedure. 4-16...
  • Page 65 Fig. 4-20B. Tube subassembly installation procedure. 4-17...
  • Page 66 RESOLUTION switches are not normally replaced. If any of these wafers are defective, the entire switch should be replaced. It can be ordered through your Tektronix Field office, either unwired or wired, as desired. Refer to the Electrical Parts List to find the unwired or wired switch part numbers.
  • Page 67 Type 491. U s e c a r e w h e n m e a s u r i n g v o l t a g e s o r w a v e f o r m s .
  • Page 68 Fig. 4-22. Power supply board assembly with component call out. 4 - 2 0...
  • Page 69 Fig. 4-23 Vertical Amplifier and Blanking board assembly with component call out. 4-21...
  • Page 70 Fig. 4-24. IF control board assembly with component call out. 4-22...
  • Page 71 Fig. 4-24. IF control board assembly with component call out. 4-23...
  • Page 72 Fig. 4-25. Horizontal display board with component call out. 4-24...
  • Page 73 Fig. 4-25. Horizontal display board with component call out. 4-25...
  • Page 74 Fig. 4-26. Phase lock board with component call out. 4-26...
  • Page 75 This section of the manual provides a means of checking 12. BNC T connector. Tektronix Part No. 103-0030-00. the performance of the Type 491. It is intended to check 13. Two (2) BNC coaxial cables, 50 W. Tektronix Part the calibration of the instrument without performing the com- No.
  • Page 76 Type 491. Turn the POWER switch to smoothly from no illumination with the SCALE ILLUM control ON and allow at least 20 minutes warm up time at 25° C fully counterclockwise to maximum illumination with the con- ±5°...
  • Page 77 O F F b. Connect the test oscilloscope probe to the SAW OUT VERTICAL DISPLAY L I N connector on the rear panel of the Type 491. Adjust the test oscilloscope triggering controls for a triggered sweep Band Selector ramp display.
  • Page 78 20 dB attenuator pad. (Signal input to the Type Table 5-2. (See Figs. 5-2 and 5-3.) The Horizontal POSI- 491 should be less than -30 dBm to reduce the number TION control or the IF CENTER FREQ control may be used of spurious signals.)
  • Page 79 play linearity must remain within listed specifications of Table 5-2 to the + and - 25 MHz positions. g. Center the coarse IF CENTER FREQ control. Set the DISPERSION control to 1 MHz position and apply 10 ns and 1 µs markers from the Time-Mark Generator. h.
  • Page 80 Center the IF CENTER FREQ controls and change the DISPERSION to 50 kHz/div. Apply 10 ns and 10 µs (100 kHz markers) to the Type 491 RF INPUT. d. Check-the range of the IF CENTER FREQ-FINE control. Must equal or exceed 50 kHz either side of center.
  • Page 81 Fig. 5-5 Equipment block diagram showing setup to check attenuator accuracy. f. Switch the band selector to A, adjust the GAIN con- T A B L E 5 - 3 trol if required for a satisfactory 1 MHz marker amplitude and turn the RF CENTER FREQUENCY control to align the tunable markers with the fixed markers.
  • Page 82 19. Check Attenuation Range of IF GAIN Control 1. Switch the Type 491 1 dB attenuator siwtch to ON and switch out 1 dB of attenuation through the units step attenua- a. Requirement-The IF GAIN control range should equal tor.
  • Page 83 Set the VERTICAL DISPLAY switch to LIN, adjust the amplitude is again 8 divisions. This checks that the range Signal Generator output and the Type 491 GAIN control of the control equals or exceeds 50 dB. for a signal amplitude of 6 divisions.
  • Page 84 A d j u s t M I X E R P E A K I N G f o r m a x i m u m s i g n a l a m p l i t u d e the signal generator output attenuator and the Type 491 before checking flatness.
  • Page 85 . C e n t e r t h e I F C E N T E R F R E Q c o n t r o l s a n d t h e F I N E listed in the Table 5-7. Switch the Type 491 Band Selector RF CENTER FREQ control, then tune the signal to the center to the appropriate band.
  • Page 86 towards the center of the display, merge over the IF feed- through response than separate and move off the screen, as the center frequency is tuned through 100 MHz check points on the dial. See Fig. 5-8. Error between the dial readings and the frequency check points must not exceed ±...
  • Page 87 SION to 500 kHz/div and the RESOLUTION control fully h. Measure band C for spurious signals as above. clockwise. This concludes the performance check for the Type 491. d. Adjust the GAIN control for an average noise ampli- tude of 1 division then tune the RF CENTER FREQUENCY...
  • Page 89 This assures proper apera- 5. Constant Amplitude Signal Generator. 1 MHz to 10 tion or indicates the section of the instrument that needs MHz amplitude 1 V to 5 V peak to peak. Tektronix Type calibration. 191 Constant Amplitude Signal Generator.
  • Page 90 Fig. 6-1. Test equipment recommended for calibration of the Type 491.
  • Page 91 dial accuracy, receiver sensitivity and response flatness. Fig. 6-2. Test equipment recommended to measure the...
  • Page 92 . Tektronix 4500 MHz. Part No. 103-0045-00. Polarad 1107 Microwave signal generator, 3.8 GHz to attenuator, BNC connector. Tektronix Part No. 8.2 GHz. 011-0059-00. Polarad 1108 Microwave signal generator, 6.95 GHz to A d j u s t i n g T o o l s . See Fig. 6-3.

  • Page 93: Table Of Contents

    Adjust Sweep Length R759, for 7.5 volt peak to peak This Abridged Calibration Procedure is provided to aid in sawtooth, at pin S of the Horizontal Display board. checking the operation of the Type 491/R491. may be used as a calibration guide by the experienced calibrator, or as a Adjust Sweep Calibration and Sweep Gain.
  • Page 94 RF INPUT connector Set the RESOLUTION control fully clockwise. Adjust of the Type 491. Check the accuracy of each IF the 100 kHz Resolution Cal R543, for a resolution A T T E N U A T O R d B s e l e c t o r a g a i n s t t h e c a l i b r a t e d bandwidth between 100 kHz and 120 kHz at the –6...

  • Page 95: Calibration Procedure

    Turn N O T E the Type 491 power switch to on and allow at least 20 minutes warmup at 25° C, ±5° C before checking the instru- W h e n p e r f o r m i n g a c o m p l e t e r e c a l i b r a t i o n , b e s t ment to the given accuracy.

  • Page 96: Adjust The -10 Volt Supply

    Fig. 6-4. Equipment setup for adjusting and checking the low and high voltage power supplies. Steps 1 through 6. T y p e 4 9 1 VIDEO FILTER VERTICAL DISPLAY L I N C R T C o n t r o l s G A I N Midrange I N T E N S I T Y...

  • Page 97: Adjust The High Voltage Power Supply

    a. Equipment setup is shown in Fig. 6-4. 3. Adjust High Voltage Power Supply b. Turn the POWER switch to ON position, then connect a. Test equipment setup is given in step 2. a calibrated voltmeter between pin K on the Vertical Ampli- b.

  • Page 98: Adjust Intensity Range

    Volt- age regulation and typical ripple amplitudes are listed in Table 6-2. The input line voltage to the Type 491 is adjusted by means of the autotransformer which is connected between the source and the Type 491 input power connector.

  • Page 99: Adjust Trace Alignment

    The following calibration steps do not require a line voltage control unit. Return the Line Voltage Selector to the operating range for the existing power source voltage. The Type 491 may be connected directly to the power source for the remainder of the calibration. 6. Adjust Trace Alignment setup is given in step 5.
  • Page 100 Fig. 6-9. Test equipment setup for adjusting Vertical Amplifier Gain. SEARCH MIXER PEAKING Type 491 Centered FINE RF CENTER FREQ Display of nominal I N T E N S I T Y OFF or EXT REF FREQ PHASE LOCK Controls...

  • Page 101: Adjust Vertical Amplifier Gain

    . A d j u s t t h e V e r t i c a l A m p l i f i e r G a i n R 6 7 2 ( F i g . 6 - 1 0 ) for a signal amplitude on the Type 491 of 5 major divisions.

  • Page 102: Adjust Trigger Level Centering

    All switches in off position d. Adjust the output of the Audio Generator for 0.2 divi- IF CENTER FREQ Midrange (000) sion (1 minor division) display amplitude on the Type 491. VIDEO FILTER O F F VERTICAL DISPLAY L I N e.

  • Page 103: Check External Triggering

    Remove the audia signal connection from pin H of the Vertical Amplifier circuit board and apply the signal to both the TRIG IN connector on the rear panel of the Type 491 and to a test oscilloscope so the signal amplitude may be monitored.

  • Page 104: Check Line Triggering

    Fig. 6-13. Setup to check LINE triggering operation. C A U T I O N 11. Check line Triggering Use special care to avoid shorting the transformer t e r m i n a l t o g r o u n d o r o t h e r t r a n s f o r m e r t e r m i n a l . a.

  • Page 105: Adjust Sweep Length

    VIDEO FILTER O F F to pin H of the Vertical Amplifier circuit board. Set the Type L I N VERTICAL DISPLAY 491 TIME/DIV selector Midrange to .1 ms. Adjust the LEVEL control for G A I N a triggered display.

  • Page 106: Check Sweep Timing Accuracy

    Sweep Gain R813 (see Fig. 6-15) for 10.5 divisions of sweep the SAW OUT connector on the rear panel of the Type 491. length. Adjust Sweep Cal R787 for 1 marker per division. S w e e p t i m i n g m u s t b e w i t h i n ± 3 % ( 1 . 2 m i n o r d i v i s i o n s ) over the center 8 graticule divisions.

  • Page 107: Check Unblinking Waveform

    Establish zero volt reference level on the test oscillo- scope by connecting the probe to chassis ground on the Type 491, then connect the probe to pin P of the square pin con- nector for the honeycomb assembly. See Fig. 6-17.
  • Page 108 Fig. 6-19. Test equipment setup to adjust and check dispersion accuracy. Type 491 F I N E R F C E N T E R F R E Q Centered PHASE LOCK Controls Display of nominal I N T E N S I T Y...
  • Page 109 B RF INPUT connector, Set the VERTICAL DISPLAY switch to LOG position. c. Adjust the Type 491 GAIN control for a display ampli- tude of approximately 6 divisions. See Fig. 6-20. Set the SOURCE switch to LINE and adjust the LEVEL control a triggered display.

  • Page 110: Check The Dispersion Accuracy For Each Mhz/Div

    d . A d j u s t t h e D I S P E R S I O N C A L R 2 0 8 ( F i g . 6 - 2 2 ) f o r 1 marker/division over the center 8 graticule divisions, then adjust C358 for display linearity.

  • Page 111: Adjust If Amplifier Response And

    Fig. 6-23. Test equipment setup to adjust IF amplifier and the resolution bandwidth. Type 491 G A I N Midrange P O W E R I N T E N S I T Y Display of nominal MIXER PEAKING SEARCH...
  • Page 112 Fig. 6-24. Location of narrow band IF amplifier adjustments. Fig. 6-26. Display pattern when resolution is correctly adjusted. 1. Install the Waveguide Mixer Adapter into band C, RF INPUT receptacle. Apply the 200 MHz signal from the Time- Mark Generator through a 20 dB attenuator and adapter to the Waveguide Mixer adapter.
  • Page 113 RESOLUTION fully clockwise, IF ATTENUTOR for 20 dB, and adjust the GAIN control for a signal amplitude of 8 divisions. k. Check the Type 491 resolution bandwidth at the -6 dB Center the display with the IF CENTER FREQ controls. Tune point.
  • Page 114 Fig. 6-29. Test equipment setup to adjust and check kHz/DIV dispersion accuracy. Type 491 VIDEO FILTER O F F Midrange G A I N Display of nominal I N T E N S I T Y P O W E R...
  • Page 115 b, Apply 10 ns and 1 µs markers from the Time-Mark Generator through the 20 dB attenuator to the band A RF IN- PUT. Set the DISPERSION to 500 kHz/div. Preset the DIS- PERSION BAL R234, to its midrange position and the kHz/div Cal R368 (Fig.
  • Page 116 d. Center the IF CENTER FREQ controls and change the DISPERSION to 50 kHz/div. e. Apply 10 ns and 10 µs markers from the Time-Mark Generatar to the RF INPUT. f. Check-the range of the IF CENTER FREQ-FINE control. Must equal or exceed 50 kHz either side af center. g.
  • Page 117 Fig. 4-32. Test equipment setup to check or adjust the phase lock circuit. MIXER PEAKING SEARCH Type 491 RF CENTER FREQ Centered FINE Display of nominal INTENSITY PHASE LOCK Controls brightness INT REF FREQ Adjusted for optimum FOCUS AND ASTIGMATISM...
  • Page 118 F i g . 6 - 3 4 . L o c a t i o n o f L 1 1 0 4 a n d 1 1 1 0 8 , R 1 1 5 0 a n d R 1 1 4 0 . e.
  • Page 119 f. Adjust L1104 (Fig. 6-34) until the oscillator shift range, b . T u r n t h e I N T R E F F R E Q c o n t r o l O N a n d t h e b a n d as the INT REF FREQ is rotated, is 1.2 kHz.
  • Page 120 Fig. 6-35. Test equipment setup to check dynamic range, IF GAIN control range, IF ATTENUATOR dB accuracy RECORDER signal out ampli- tude and incidental FM. Type 491 LEVEL F R E E R U N S O U R C E...
  • Page 121 . A d j u s t t h e G A I N c o n t r o l a n d t h e V a r i a b l e O u t p u t 16 dB 5.0 to 7.2 div Attenuator for a display amplitude on the Type 491 of 8 20 dB 4.8 to 7.5 div divisions.
  • Page 122 F i g . 6 - 3 6 . T y p i c a l V i d e o F i l t e r i n t e g r a t e d d i s p l a y o f 2 0 0 M H z R F Fig. 6-37. Typical display showing incidental frequency modulation, division signal amplitude on the Type 491. Note the dBm 3 3 .
  • Page 123 F M a n d g. Change the DISPERSION to 100 kHz/div and move the the Type 491 must be on a vibration-free platform. IF feedthrough signal off screen with the IF CENTER FRE- QUENCY control.
  • Page 124 Fig. 6-38. Equipment setup to adjust wide band IF amplifier and check flatness. Type 491 F I N E R F C E N T E R F R E Q Centered PHASE LOCK Controls I N T E N S I T Y...
  • Page 125 Turn the 20 dB ATTENUATOR switch for the Type 491 to the ON position. Adjust the variable output attenuator on the signal generator for an approximate 3 mV display amplitude on the test oscilloscope. e. Adjust L147 (Fig. 6-39), the 65 MHz trap, for minimum response to the 65 MHz signal.
  • Page 126 100 MHz Adjust the signal generator output attenuator and the from RF center frequency). Maximum signal amplitude Type 491 GAIN control for a signal amplitude of 6 divi- with the MIXER PEAKING control before measuring flat- sions. ness.
  • Page 127 Fig. 6-40. Equipment setup to check internal spurious responses. MHz/DIV DISPERSION RANGE Type 491 INTENSITY Display of nominal bright- D I S P E R S I O N ness R E S O L U T I O N F u l l y C W FOCUS &...
  • Page 128 Fig. 6-41. Typical equipment setup to check response flatness, sensitivity, frequency calibration and phase lock operation. Adjust Band A Mixer Balance—Check h. Move the 50 termination to band B RF INPUT con- nector, switch the band selector to B and set the DISPER- Amplitude of Spurious Signals from Internal SION to 10 MHz/div.
  • Page 129 -60 dBm and -30 dBm, to the appropriate RF tion, however, a very stable signal source is required at the INPUT connector. Switch the Type 491 band selector switch higher frequencies. Sweep speed must be rduced to 50 ms/ to the appropriate band.
  • Page 130 Amplitude Signal Generator (Type 191) to the REF FREQ IN connector. Use a BNC T connector to apply the in- put signal to the Type 491 to provide a convenient monitor- ing point for the test oscilloscope. The input signal voltage must be measured at the REF FREQ IN connector.
  • Page 131 TABLE 6-9 Suggested Frequency Band Sensitivity Signal Generator (Equal to or better than) Dial Accuracy 100 kHz (Refer to equipment list) 1 kHz Check Frequency Hewlett-Packard 10 MHz Model 608D -80 dBm -100 dBm Every 10 MHz -90 dBm -110 dBm Every 100 MHz Hewlett-Packard Model 612A...
  • Page 132 Fig. 6- 45. Alternate equipment setup that will check dial accuracy, mixer and oscillator operation, and LO phase lock effectiveness. tor signals. Tune the RF CENTER FREQUENCY through the 38B. Alternate Procedure to Check Dial Accur- band, checking for dead spots which could be caused by acy, Oscillator Mixer Operation and Ef- either local oscillator failure or mixer malfunction.
  • Page 133 RF section after minor repair, such as oscillator tube replacement. If possible we recommend the complete RF assembly or the com- plete unit be returned to Tektronix for repair, See your local Tektranix Field Office or representa- tive.
  • Page 134 2. Switch the band selector switch to B. points, including each end of the band. The oscillator fre- 3. Push the LOCK CHECK button and adjust the Type 491 quency must track within ±1% of the dial frequency +200 FINE RF CENTER FREQ control for a centered trace or +7.0 M H z .
  • Page 135 Tektronix for repair and calibration. between the drive shaft and the tuning shaft (see Fig. 6-48).
  • Page 136 The spring-like wires protruding from the side wall. assembly should be returned to Tektronix for repair and calibration. See your local Tektronix Field Office or repre- 4. If the dial reading in step 2 was above 270, more sentative.
  • Page 137 calibration. See Maintenance Section. The probe assemblies 100 mW, decrease the coupling by pulling the probe as- can be oriented within the magnetic field of the oscillator sembly out. Tighten the set screws. chamber by loosening set screws and positioning the probe i.
  • Page 139 PARTS LIST ABBREVIATIONS binding head brass internal length or long binding head steel met. metal capacitor cap. mtg hdw mounting hardware ceramic outside diameter composition comp oval head brass corm connector oval head steel cathode-ray tube pan head brass countersunk pan head steel double end plstc...
  • Page 140 Part first added at this serial number Part removed after this serial number Asterisk preceding Tektronix Part Number indicates manufactured by *000-0000-00 or for Tektronix, Inc., or reworked or checked components. Use 000-0000-00 Part number indicated is direct replacement Screwdriver adjustment.
  • Page 141 SECTION 7 ELECTRICAL PARTS LIST Values are fixed unless marked Variable. Tektronix Serial/Model No. Ckt. No. Part No. Disc Description Bulbs B901 150-0045-00 Incandescent #685 B942 150-0059-00 Incandescent #386 B943 150-0059-00 h-tcandescent #386 Capacitors Tolerance &20~~ unless otherwise indicated. 283-0067-00 B1 19999 0.001 ~F...
  • Page 142 Capacitors (contj Tektronix Serial/Model No. Part No. Description Ckt. No. Disc Cl 28 283-0065-01 100V 5=)” 0.001 cl 30 283-0103-00 180 pF 500 v Cl 32 283-0039-00 0.001 pF 500 v C133 281-0635-00 1000 pF 500 v 281-0616-00 XB040000 6.8 pF...
  • Page 143 Capacitors (corrtj Tektronix Serial/Model No. Ckt. No. Part Disc Description C365 283-0025-00 0.0005 pF 500 v C367 283-0039-00 500 v 0.001 /LF C368 283-0003-00 0.01 /.LF 150V C373 283-0039-00 0.001 pF 500 v C376 283-0039-00 0.001 pF 500 v C383 283-0039-00 0.001 pF...
  • Page 144 Capacitors (contj Tektronix Serial/Model No. Description Part No. Disc Ckt. No. 500V C525 283-0039-00 0.001 /bF C527 283-0003-00 150V 0.01 ILF 283-0003-00 150V C530 0.01 pF C534 150V 283-0003-00 0.01 /.LF 150V C537 283-0003-00 0.01 /LF 150V 283-0003-00 0.01 pF...
  • Page 145 Capdta9 (cent) Tdrtronix SoriaVModei No. Part Disc Description Ckt, No. 283-0079-00 0.01 AF 250 v C741 1000pF 500V 281-0536-00 2834027-00 O.)$:F# C755 281-0575-00 C761 283-0078-00 O.(B1 /AF 500V c705A 10PF C7858 C785C :.?@ %?9s-01034) liming Series C78SD 0.01 @ C785E 0.001 pF 0.01 # 283-00794X)
  • Page 146 Capacitors (cent) Tektronix Serial/Model Part No. Disc Description Ckt. No. 200 v +80~o—20% cl 020 283-0092-00 0.03 pF 4000 v +807!0 –20% cl 021 283-0082-00 0.01 pF 5000 v Cl 025 283-0021-00 0.001 pF 150V 283-0004-00 0.02 pF cl 032...
  • Page 147 Diodes Tektronix Serial/Model No. Part No. Disc Description Ckt. No, Germanium 1 N82A (matched pair) *1 53-0024-00 Varicap 6.8 pF 152-0272-00 Silicon 1N416D 152-0194-00 Silicon 152-0197-00 Silicon 1N415D Microwave Mixer 152-0363-00 Silicon Microwave mixer 152-0364-00 Silicon Microwave mixer Microwave Mixer...
  • Page 148 Diodee (Contj Tektronix Serial/Model No. Ckt. No. Part Disc Description 152.oo75~ D742 Tek Spec Germanium *1 52-0075-00 Tek SDOC D744 Germanium D767 *1 52-0185-00 Replo&able by 1 N4152 Silicon D76B *1 52-0185-00 Silicon Replaceable by 1 N4152 D770 *1 52-0075-(X)
  • Page 149 Tektronix Serial/Model No. Description Port Disc Ckt. No. 0.5 A 3AG Fast-Blo 159-0025-00 1 A 3AG Fast-Blo F902 159-0022-00 1 A 3AG Fast-Blo F1 008 1594022-00 Piltor 8010100 FL900 119-0095-00 8059999 Low Pass 275 V AC 119-0095-03 Low Pass 275 V AC...
  • Page 150 Connectors (corst) Tektronix Serial/Model No. Ckt. No. Part No. Disc Description J151 131-0372-00 Coaxial J188 131-0372-00 Coaxial J363 131-0372-00 Coaxial J370 131-0372-00 Coaxial J373 131-0372-00 Coaxial J376 131-0372-00 Coaxial J379 131-0372-00 Coaxial J401 131-0372-00 Coaxial J470 131-0372-00 Coaxial J501 131-0372-00...
  • Page 151 Inductors (contj Tektronix Seriul/Model No. Part No. Ckt. No. Disc Description *1 08-0373-00 L124 BO101 00 B039999 56 nH L124 * 108-0374-00 B040000 55 nH L134 *1 14-0205-00 54-66 nH, Var Care 276-0506-00 *1 14-0206-00 L144 234-286 nH, Var Core 276-0506-00...
  • Page 152 Transistors Tektronix Serial/Model No. Ckt. No. Disc Description Part No. 151-0207-00 2N3415 Silicon 151-0207-00 Silicon 2N3415 BO1O1OO B039999 Q120 151-0180-00 Silicon 40235 (RCA) Q120 * 151-0230-00 B040000 Silicon Replaceable by 40235 (RCA) Q130 151-0180-00 BO101 00 B039999 40235 (RCA) Silicon...
  • Page 153 Traneietom (cent) Tektronix Serial/Model No. Ckt. Part Disc Description *] 51.019.2.00 Q760 Replaceable by MPS 6521 5ilicon Q761 151 -0192-00 Replaceable by MPS 6521 Silicon Q770 151-0188-00 Silicon 2N3906 Q771 151-0188-00 Silicon 2N3906 *151 .0192-00 Q790 Silicon Replaceable by MPS 6521...
  • Page 154 (contJ Resistore Tektronix Serial/Model No. Description Part No. Disc Ckt. No. 8010100 8119999 47 Q Selected (nominal value) 315-0470-00 8120000 Selected (nominal value) 317-0151-00 1500 8010100 B1 19999 33 Ct Selected (nominal value) 315-0330-00 B1 20000 150Q Selected (nominal value)
  • Page 155 Resistors (contj Tektronix Serial/Model No. Ckt. No. Part No. Disc Description R183 315-0911-00 91OQ R184 307-0107-00 5.6 Q 1/4 w RI 85 315-0911-00 910!2 ys w R200 Prec 321-0256-00 4.53 k~ yz w R201 323-0369-00 Prec 68.1 kct R203 311-0633-00 5 k~, Var ‘/4 w...
  • Page 156 Resistors (cent) Tektronix Serial/Model Part No. Ckt. No. Disc Description R263 321-0143-00 Prec 1 y. R264 321-0423-00 1/8 w Prec R266 321-0135-00 Prec R267 321-0135-00 ys w Prec R272 321-0222-00 ys w Prec R274 321-0205-00 yo w Prec 1 y.
  • Page 157 Redstore (contj Tektronix Serial/Model No. Part No. Description Ckt. No. Disc 315-0103-00 10kn R464 R466 315-0472-00 4.7 kn 150Q R501 317”0151-00 317-0151-00 15(IQ R502 R514 315-0470-00 47 Q R516 315-0242-00 2.4 ka R517 315-0242-00 2.4 k~ R524 315-0470-00 47 c?
  • Page 158 Resistors (corst) Tektronix Serial/Model No. Part No. Ckt. No. “ Disc Description R646 308-0413-00 16ki2 R650 315-0683-00 68 k~ 1/4 w 5 “/0 R651 315-0273-00 ‘/4 w 27 kf) 1/4 w R653 315-0102-00 1 k~ Q655 315-0104-00 ‘/4 w 100 k~...
  • Page 159 Resistors (cot-it) Tektronix Serial/Model No. Ckt. No. Part No. Disc Description 1/4 w R720 315-0104-00 100Q 74 w R721 315-0332-00 3.3 k~ JA w R722 315-0101-00 100Q R724 311-0613-00 100 kil, Var 1/4 w R725 315-0304-00 BO1O1O4 B099999 300 k~...
  • Page 160 Resistors (contj Tektronix Serial/Model No. Ckt. No. Part No. Disc Description 315-0101-00 R789 100Q R790 315-0623-00 62 ko R791 315-0621-00 620 Q R793 315-0101-00 100(2 R794 315-0101-00 100Q R795 315-0101-00 100Q R797 321-0452-00 499 ka Prec R799 315-0472-00 4.7 kfz...
  • Page 161 Raiders (Conf) Tektronix Serial/Model No. Ckt. No. Part Disc Description R954 321-0213-00 1.62 ks) Prec 1$’” 1/4 w R956 3150222-00 2.2 k~ y4 w R958 315-0332-00 3.3 kc) ~h w R960 315-0123-00 12kn 1/4 w !!962 315-0101-00 100Q yo w...
  • Page 162 (contj Resistors Serial/Model Tektronix Description Disc Ckt. No. Part No. R1 053 315-0102-00 R1 055 315-0471-00 470 !Q ‘/8 Prec RI 057 321-0239-00 3.01 k~ ‘/4 w 100Q R1 059 315-0101-00 Prec 321-0320-00 21 k$d RI 062 311-0310-00 5kQ, Var R1 063 ‘/8 w...
  • Page 163 Resistors (conf) Tektronix Serial/Model Ckt. No. Part No. Disc Description RI 136 *308-0277-00 500 f-l iv137 315-0100-00 R1 13t? 315-0510-00 51 K? R1140 311-0635-00 1 kn, Var R1 141 315-0912-00 9.1 kn R1142 321-0306-00 15kQ Prec Prec R1143 321-0251-00 4.02 k~...
  • Page 164 Reeistors (corrtj Tektronix Serial/Madel Part No. Disc Description Ckt. No. y4 w 120 kCt 315-0124-00 RI 197 y4 w 315-0302-00 3 k~ RI 198 y4 w R1199 315-0205-00 2 M$2 57” Resistive “T” Network (includes J50, J51, J52) 119-009140 119-0066-00...
  • Page 165 Transformers Tektronix Serial/Model No. Part No. Disc Description Ckt. No. *1 20.- 5 turns, bifilor &l ~@28.~ T120 4 turns, bifilar 5 turns, bifilar 5 turns, bifilar 5 turns, bifilar 5 turns, bifilar T331 5 turns, bifilar 5 turns, bifilar...
  • Page 166 Cable Assemblies (contj Tektronix Serial/Model No. Disc Description Ckt. No. Part No. *1 75-0313-00 W150 41/d inch W200 *175-0358-00 213/ld inch W300 *1 75-0358-00 BO101 00 B059999 inch 213/,6 W300 *1 75-0413-00 B060000 81/4 inch W370’8 W375’8 W500 *1 75-0358-00...
  • Page 167 FIGURE AND INDEX NUMBERS Items in this section are referenced by figure and index numbers to the illustrations which appear on the pullout pages immediately following the Diagrams section of this instruction manual. INDENTATION SYSTEM This mechanical parts list is indented to indicate item relationships. Following is an example of the indentation system used in the Description column.
  • Page 168 FIG. 2 REAR FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES FIG. 4 POWER CHASSIS FIG. 5 TIME/DIV SWITCH & OSCILLATOR ASSEMBLIES FIG. 6 CRT SHIELD ASSEMBLY FIG. 7 CABINET ASSEMBLY & HANDLE FIG. 8 491 ACCESSORIES 7 - B...
  • Page 169 SECTION 8 MECHANICAL PARTS LIST FIG. 1 FRONT Fig. & Index Tektronix Serial/Model No. Description Part No. Disc 12345 3644392-00 KNOB, charcoal-lNTENSITY knob includes: il&9i9&- SPRING 366-0392-00 KNOB, charcaal-FC)CUS knob includes: il&& SPRING 366439240 KNOB, charcoal-SCALE ILLUM . ..- knob includes:...
  • Page 170 FIG. 1 FRONT (cont) Fig. & Serial/Model Index Tektronix Description Disc Part No. 12345 KNOB. charcoal lever—TRIGGER [SOURCEI 1-22 366-0215-02 - 2 3 260-0665-00 SWITCH, lever—TRIGGER (SOURCE) “ mounting hardware: (not included w/switch) - 2 4 ;2~-&;3:W- NUT, hex., 4-40 x 0.562 inch long...
  • Page 171 FIG. 1 FRONT (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 1-44 199-0066-00 ATTENUATOR, pad mounting hardware (not included w/attenuator) ili-ioio:& WASHER, flat, 0.643 ID x 0.875 inch OD MIXER, w/crystal 119-0064-00...
  • Page 172 FIG. 1 FRONT (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Disc Part No. 12345 1 - 7 1 376-0068-00 COUPLING ..- coupling includes: SCREW, set, 4-40 x ‘/8 inch, HSS...
  • Page 173 FIG. 2 REAR Fig. & I n d e x Tektronix Serial/Model No. Description Disc Part No. 12345 ASSEMBLY, cable, 10 inches (J69 to J72) 2 - 9 8 175-0415-00 BO101 00 B090409 ASSEMBLY, cable, 10 inches (J69 to J72)
  • Page 174 FIG. 2 REAR (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Disc Part No. N o . 12345 BRACKET 2 - 2 0 407-0272-00 ---- . . mounting hardware: (not included w/bracket) SCREW, 6-32 x ‘/z inch, 100° csk, FHS...
  • Page 175 FIG. 2 REAR (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 2 - 4 7 179-1097-00 BO101 00 8019999 CA8LE HARNESS, high voltage & CRT 179-1194-00 B020000 BI 19999 CA8LE HARNESS, high voltage & CRT...
  • Page 176 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 610-0175-00 ASSEMBLY, lF CHASSIS assembly includes: ilo-ol;3:oo ASSEMBLY, IF ATTENUATOR dB ..-...
  • Page 177 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES (cont) Fig. & Serial/Model No. I n d e x Tektronix Description Disc Part No, 12345 SOCKET, transistor, 4 pin 3 - 2 6 136-0217-00 ..- mounting hardware for each: (not included w/socket)
  • Page 178 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES ( c o n t ) Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 LUG, solder, #2 3 - 5 4 210-0259-00 ..-...
  • Page 179 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES (cont) Fig. & Index Tektronix Serial/Model No. Description Part No. Disc 12345 ..RESISTOR, variable 3-75 -.. . mounting hordware (not included w/resistor] (not shown) ;1 i-l 042-00 LOSKWASHER, internal, 0,285 ID x 0.50 inch OD...
  • Page 180 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 3-102 337-0879-00 SHIELD ..-. . . mounting hardware: (not included w/shield) -103 213-0138-00 SCREW, sheet metal, #4x 3/it inch, PHS...
  • Page 181 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES (cont) Fig. & Serial/Model No. Index Tektronix Description Disc Part No. 12345 SHIELD, filter 3-123 337-0805-00 ----- . mounting hardware for each: (not included w/shield) -124 213-0138-00 SCREW, sheet metal, #4x 3/14 inch, PHS...
  • Page 182 FIG. 4 POWER CHASSIS Fig. & Index Tektronix Serial/Model No. Description Part No. Disc 12345 4 - 1 ------ TRANSFORMER mounting hardware: (not included w/transformer) ;12-0522:00 SCREW, 10-32 x 21/2 inches, HHS 210-0812-00 WASHER, fiber, #1 O 354-0019-01 RING 220-0410-00...
  • Page 183 FIG. 4 POWER CHASSIS (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Disc Part No. 12345 ..TRANSISTOR 4-30 mounting hardware: (not included w/transistor) SCREW, 6-32 x % inch, PHS ;l-1 -;5; 0:4...
  • Page 184 FIG. 4 POWER CHASSIS (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 BUSHING, plastic 4-57 358-0215-00 ASSEM8LY, circuit board—lF CONTROL 670-0505-00 ---- -- assembly includes: BOARD, circuit 388-0799-00 214-0506-00 PIN, connector, male...
  • Page 185 FIG. 5 TiME/DIV SWITCH & OSCILLATOR ASSEMBLIES Fig. & I n d e x Tektronix Serial/Model No. Description N o . Part No, Disc 12345 262-0787-00 SWITCH, wired—TIME/DIV ..switch includes: 260-0819-00 SWITCH, unwired ------...
  • Page 186 FIG. 5 TIME/DIV SWITCH & OSCILLATOR ASSEMBLIES (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Disc Part No. 12345 CA8LE HARNESS, sweep 5 - 2 7 179-1093-00 cable harness includes: CONNECTOR, single contact - 2 8 ; 3; -;3;1 ~00...
  • Page 187 FIG. 5 TIME/DIV SWITCH & OSCILLATOR ASSEMBLIES (cont) Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 SHAFT 5 - 4 2 384-0423-00 mounting hardware for each: (not included w/shafi) CLIP, retaining - 4 3 &-ili7:&...
  • Page 188 FIG. 5 TIME/DIV SWITCH & OSCILLATOR ASSEMBLIES (cont) Fig. & Index Tektronix Serial/Model No. Description N o . Disc Part No. 12345 BRACKET, support 5 - 6 4 407-0294.00 BRACKET, support - 6 5 407-0295-00 mounting hardware: (not included w/brocket) &io;4:o;...
  • Page 189 FIG. 6 CRT SHIELD ASSEMBLY Fig. & i n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 ASSEMBLY, CRT shield 626-0440-00 ----- . assembly includes: Figure -1 337-0754-00 SHIELD, CRT .. ---- Figure -2 COIL ---- mounting hardware: (not included w/coil) ;1 i -0590-00 BO10100...
  • Page 190 FIG. 7 CABINET ASSEMBLY AND HANDLE Fig. & I n d e x Tektronix Serial/Model No. Description Part No. Disc 12345 ASSEMBLY, cabinet 437-0088-01 ----- - assembly includes: 348-0079-00 FOOT, plastic cap FOOT, plastic 348-0078-00 ..- mounting hardware for each: (not included w/foot) SCREW, 8-32 x 1 ‘/z inches, RHS...
  • Page 191 APPENDIX A BASIC ISSUE ITEMS LIST Basic issue items list will be published at a later date.
  • Page 193 APPENDIX B MAINTENANCE ALLOCATION CHART Section I. INTRODUCTION B-1. General This Maintenance Allocation Chart designates overall responsibility for the performance of maintenance functions on the identified end item or component. The implemeatation of field maintenance tasks upon this end or component will be consistent with the assigned maintenance opera- item tions.
  • Page 194 Overhaul. Normally, the highest degree of maintenance performed by the Army in order to minimize tine work in process is consistent with quality and economy of operation. It consists of that maintenance necessary to re- store an item to completely serviceable condition as prescribed by mainte- nance standards in technical publications for each item of equipment.
  • Page 197 APPENDIX C REPAIR PARTS LIST C-1. This appendix provides a list of repair parts for maintenance support of the equipment. The parts along with their descriptions are listed in table C-1 below. C-2. Instructions for requisitioning parts not identified by Federal Stock Numbers require the following information be furnished to the Supply Officer: a.
  • Page 198 Table C-1. Repair Parts List Nomenclature C& FSiV ———— . —— BULB INCAND 150--0045-00 80009 6240-333-5821 !30909 BULB INCAND 150-0059-00 6240-941-2683 59ijl.~23-977~ XSTR SP8481 151-0104-00 80009 XSTR SIL 4!YJ B 151-0108-00 80009 5961-759-9392 XSTR 2N3053 151-0;36-00 80009 XSTX SIL 2N.305S 151-0140-00 80009 5961-724-2J38...
  • Page 199 TM 9-6625-2467-15 By Order of the Secretary of the Army: W. C. WESTMORELAND, General, United States Army, Official: Chief of Staff. KENNETH G. WICKHAM, Major General, United States Army, The Adjutant General. Distribution: To be distributed in accordance with DA Form 12-37 (qty rqr block No.
  • Page 201 SECTION 9. DIAGRAMS MECHANICAL PARTS LIST ILLUSTRATIONS ACCESSORIES...
  • Page 208 9-11...
  • Page 209 9 - 1 3...
  • Page 210 9-15...
  • Page 211 9-17...
  • Page 212 9-19...
  • Page 213 9-21...
  • Page 214 9-23...
  • Page 215 9-25...
  • Page 216 9-27...
  • Page 217 FIG. 1 9-29...
  • Page 218 FIG. 2 REAR 9-31...
  • Page 219 FIG. 3 IF CHASSIS & PHASE LOCK ASSEMBLIES 9-33...
  • Page 220 FIG. 4 POWER CHASSIS 9-35...
  • Page 221 FIG. 5 TIME/DIV SWITCH & OSCILLATOR ASSEMBLIES 9-37...
  • Page 222 FIG. 6 CRT SHIELD ASSEMBLY 9-39...
  • Page 223 FIG. 7 CABINET ASSEMBLY & HANDLE 9 - 4 1...
  • Page 224 FIG. 8 491 STANDARD ACCESSORIES FIG. 8 491 STANDARD ACCESSORIES 9-43...
  • Page 226 PIN: 028017-000...

Table of Contents