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Theory of Operation

4- 16

1705A Spectrum Monitor

increases, causing the voltage across R96 to increase. This voltage is divided by
R87 and R101, and is applied to the comparator (pin 3). When the voltage at U5
pin 3 reaches the comparator trip point, the latch toggles and the switcher mosfet
is turned off. This process is repeated at an 80 kHz rate.

C58 increases the PWM noise immunity by rolling off the internal op-amp
frequency response. R82 holds the switcher mosfet off as the circuit is powering
up. R81 slows the turn-on of the switcher mosfet while CR27 speeds up the turn
off.

The three output windings supply four output voltages. Each output is rectified
by a single diode and filtered by an LC pi filter.

The Error Amplifier regulates the +5 V output by feeding an error signal to the
Pulse Width Modulator. VR1 is a 2.5 V shunt regulator containing an op-amp
and a voltage reference. The +5 V is divided by R69 and R70 to provide 2.5 V
to VR1, with fine adjustment provided by R99. C40 and R71 determine the gain
and frequency response of VR1. VR4 controls overshoot of the +5 V at power
up. R98 and CR26 provide a minimum operating current for VR1. R68
decouples C39 from VR1. Overvoltage protection for the +5V supply is
provided by a crowbar circuit formed by Q11, VR3, R13, and R14.

The 80 kHz sawtooth waveform at U3 pin 3 trips comparator U3. U3 pin 1 then
feeds a trigger pulse to one-shot U4. U4 pin 13 outputs a 300 nS pulse to the
130 mA current source consisting of Q7 and Q8. When Q8 turns on, T2 pin 2 is
pulled down until CR15 (Error Amplifier) is forward biased. The negative-going
pulse at T2 pin 2 is peak detected by CR16 and C46. The dc voltage present at
the anode of CR16 feeds the pulse width modulator and the Output Under-Volt-
age Shutdown circuit. CR29 resets T2 between pulses.

If the +5 V is below 4.9 V, the Error Amplifier will cause the Peak Detector
output to go below 2.9 V. The output of comparator U3B will pull low and shut
down pulse width modulator U5. C47 and R96 delay the operation of U3B long
enough for the power supply to power up. If the +5 V does not reach 4.9 V
within 50 ms of power up, U3B will shut down the switcher. The power supply
will then cycle on and off every couple of seconds.

Output Filters

Error Amplifier

Feedback Transformer

Driver and Peak Detector

Output Under-Voltage

Shutdown

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Summary of Contents for 1705A

Page 1: ...e for use by qualified personnel only To avoid personal injury do not perform any servicing unless you are qualified to do so Refer to all safety summaries prior to performing service www tektronix com Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 FAX 781 665 0780 TestEquipmentDepot com ...

Page 2: ...tprints 1 10 Using the 1705A for Satellite Communication 1 11 L Band Input Signals 1 12 Zeroing in on a Satellite 1 13 Locating the Satellite 1 13 Identifying the Satellite 1 13 Finding The Correct Transponder 1 15 Optimize Signal Strength 1 15 Looking at Exciters with the 70 MHz Input 1 16 Miscellaneous Uses for the 1705A 1 17 Operating Instructions Section 2 Operating Instructions 2 1 Front pane...

Page 3: ...Options 3 2 Mechanical Installation 3 2 Cabinet Options 3 2 Cabinetizing 3 4 Rack Adapter 3 5 Custom Installation 3 8 Theory of Operation Section 4 Theory of Operation 4 1 Overview 4 1 Block Diagram 4 1 RF Input Circuits Diagram 1 4 1 IF Amplifier Circuits Diagram 2 4 2 Sweep Generator Circuits Diagram 3 4 2 Deflection Amplifiers Diagram 4 4 3 Microprocessor Diagram 5 4 3 Front Panel Diagram 6 4 3...

Page 4: ...8 Volt Supply 4 13 Low Voltage Power Supply Diagram 7 4 14 Line Rectifier and Filter 4 15 Pulse Width Modulator 4 15 Output Filters 4 16 Error Amplifier 4 16 Feedback Transformer Driver and Peak Detector 4 16 Output Under Voltage Shutdown 4 16 High Voltage Power Supply Diagram 8 4 17 HV Osc and Error Amp 4 17 Power Supply Outputs 4 18 Focus Amplifier 4 18 Grid Drive Circuit 4 18 Z Axis Amplifier 4...

Page 5: ... Supply Troubleshooting Procedure 6 12 Introduction 6 12 Low Volts Supply 6 13 High Volts Supply 6 15 CORRECTIVE MAINTENANCE 6 18 Obtaining Replacement Parts 6 18 Test Selected Components 6 18 Mechanical Disassembly Assembly 6 19 Bezel Removal 6 19 Graticule Light Removal and Replacement 6 20 Removal of the CRT 6 21 Replacing the CRT 6 21 Removal of the Rear Panel 6 22 Removal of Front Panel Assem...

Page 6: ...r 8 1 Abbreviations 8 1 List of Assemblies 8 1 Column Descriptions 8 2 Component No Column 1 8 2 Tektronix Part No Column 2 8 2 Serial Assembly No Column 3 and 4 8 2 Name and Description Column 5 8 2 Mfr Code Column 6 8 2 Mfr Part No Column 7 8 2 Diagrams Circuit Board Illustrations Replaceable Mechanical Parts Section 10 Replaceable Mechanical Parts 10 1 Parts Ordering Information 10 1 Using the ...

Page 7: ...t either the output of the Video Exciter 70 MHz or the Receiver Input L Band 1 18 Figure 2 1 1705A front panel 2 2 Figure 2 2 1705A rear panel controls and connectors 2 5 Figure 2 3 1705A display when powered up in L BAND and FULL SPAN 2 6 Figure 2 4 1705A graticule scale 2 7 Figure 2 5 Relationship of sweep to graticule showing minimum and maximum frequencies 2 10 Figure 2 6 Frequency relationshi...

Page 8: ...5 19 Figure 5 8 DAC check waveforms used to check Focus Astigmatism Geometry and setting of the Trace Rotation 5 20 Figure 5 9 Location of the shorting strap used when adjusting sweep length 5 21 Figure 6 1 Using the 1705A menus 6 4 Figure 6 2 1705A Test menu displayed when Test is the Main menu selection 6 5 Figure 6 3 1705A CRT display when the NOVRAM Test has been successfully completed 6 6 Fig...

Page 9: ...on 2 9 Table 2 3 Azimuth Elevation Table for 21 CONUS Cities 2 18 Table 3 1 Internal Jumper Selection 3 2 Table 5 1 Preliminary Control Settings 5 6 Table 5 2 Preliminary Control Settings 5 18 Table 6 1 Static Susceptibility 6 2 Table 6 2 Power Supply Fault Symptoms 6 12 Table 6 3 Low Volts Supply Voltages 6 13 Table 6 4 Control Circuit Test Points 6 15 Table 6 5 High Volts Supply Fault Symptoms 6...

Page 10: ...to the input or output terminals of the product ensure that the product is properly grounded Observe All Terminal Ratings To avoid fire or shock hazard observe all ratings and markings on the product Consult the product manual for further ratings information before making connections to the product Connect the ground lead of the probe to earth ground only Do not apply a potential to any terminal i...

Page 11: ...tices that could result in damage to this product or other property Terms on the Product These terms may appear on the product DANGER indicates an injury hazard immediately accessible as you read the marking WARNING indicates an injury hazard not immediately accessible as you read the marking CAUTION indicates a hazard to property including the product Symbols on the Product The following symbols ...

Page 12: ...ardous voltages for long periods of time after power is turned off Before attempting any servicing discharge the CRT by shorting the anode to chassis ground When discharging the CRT connect the discharge path to ground and then the anode Rough handling may cause the CRT to implode Do not nick or scratch the glass or subject it to undue pressure when removing or installing it When handling the CRT ...

Page 13: ...Service Safety Summary xii 1705A Spectrum Monitor ...

Page 14: ... installation informa tion The electrical installation information includes adjustments and operational changes available with the instrument The mechanical installation information includes rackmounting custom installation and portable use Section 4 Theory of Operation provides an over all block diagram description and detailed circuit descriptions Read the block diagram description for an overvi...

Page 15: ...hese include adjustment locations circuit board part locations a block diagram and schematic diagrams Parts locating tables are included that cross reference the circuit board illustra tions to the schematic diagrams Section 10 Replaceable Mechanical Parts includes ordering information and part numbers for all replaceable mechanical parts This parts list is referenced to an exploded view mechanica...

Page 16: ...s support 1 800 833 9200 select option 1 Service support 1 800 833 9200 select option 2 Technical support Email techsupport tektronix com 1 800 833 9200 select option 3 6 00 a m 5 00 p m Pacific time This phone number is toll free in North America After office hours please leave a voice mail message Outside North America contact a Tektronix sales office or distributor see the Tektronix web site fo...

Page 17: ...Preface xvi 1705A Spectrum Monitor ...

Page 18: ...Introduction ...

Page 19: ......

Page 20: ...05A Spectrum Monitor is a swept front end superheterodyne type spectrum analyzer with two inputs L Band to accommodate Low Noise Amplifier Block Down Converter LNB outputs and 70 MHz for use with Video Exciters The L Band input 950 to 1800 MHz is through an F type connector while the 70 MHz input is through a standard bnc connector The L BAND INPUT connector is the output for the selectable 18 V s...

Page 21: ...tions described in Section 7 Options If no power cord options are ordered instruments are shipped with the North American 125 V power cord and one replacement fuse Accessories 1 Manual Instruction 1 Adapter F type Male connector to BNC female connector 1 Power Cord with the correct plug for the selected power plug option 1 Replacement Cartridge Fuse correct rating for the power plug option 3 Repla...

Page 22: ...ended to operate from an ac power source that will not apply more than 250 V rms between the supply conductors or between either supply conductor and ground A protective ground connection by way of the grounding conductor is essential for safe operation The instrument was tested for compliance in a cabinet To ensure continued compliance the instrument will need to be enclosed in a cabinet that is ...

Page 23: ... come on screen in the next magnified position 4 5 10 11 11 Flatness L Band 5 dB 70 MHz 2 dB from center 1400 MHz from center 70 MHz 12 7 Maximum Signal Input L Band 30 dBm 75Ω 70 MHz 20 dBm 75Ω Minimum Signal Input 80 dBm Relative Amplitude Accuracy L Band only 3 dB 100 MHz Typically 1 dB 100 MHz 12 Sweep Length 12 Divisions all SPANS DIV settings 4 Sweep Speed Typically 20 200 ms 9 Positioning R...

Page 24: ... dc Supply LNB Power 18 Vdc 5 250 mA max Output through L BAND input connector switched on and off by rear panel slide switch LED indicator on rear panel 3 2 dB Gain Accuracy 2 dB Division 3 dB Division at 50 dBm 14 Table 1 2 CRT Display Characteristic Performance Requirements Supplemental Information Check Step Crt Viewing Area 80 X 100 mm Accelerating Potential 13 75 kV Trace Rotation Range Grea...

Page 25: ...proximately 8 5 lbs approximately 3 8 kg Table 1 6 Certifications and Compliances EC Declaration of Conformity EMC Meets intent of Directive 89 336 EEC for Electromagnetic Compatibility Compliance was demonstrated to the following specifications as listed in the Official Journal of the European Communities EN 50081 1 Emissions EN 55022 Class B Radiated and Conducted Emissions EN 50082 1 Immunity I...

Page 26: ...enerally encapsulated hermetically sealed or located in clean rooms Pollution Degree 2 Normally only dry nonconductive pollution occurs Occasionally a temporary conductivity that is caused by condensation must be expected This location is a typical office home environment Temporary condensation occurs only when the product is out of service Pollution Degree 3 Conductive pollution or dry nonconduct...

Page 27: ...perating 5 to 40_ C Altitude maximum operating 2000 meters Equipment Type Test and measuring Safety Class Class 1 as defined in IEC 1010 1 Annex H grounded product Overvoltage Category Overvoltage Category II as defined in IEC 1010 1 Annex J Pollution Degree Pollution Degree 2 as defined in IEC 1010 1 Note Rated for indoor use only ...

Page 28: ...e earth s surface Without being geostationary using a satellite would be extremely complicated and the calculations required to determine when they were in the usable window and how long they would stay there would in most cases require a computer At 35 900 km distance the earth subtends an angle of 18 which provides coverage of approximately 40 of the earth s surface See Figure 1 2 Forty percent ...

Page 29: ...ot be used to find a satellite Figure 1 4 confirms that the angle from the prime meridian to a satellite will be considerably different than the angle from a North American or European earth station to the same satellite It should also be noted that the elevation also decreases for a satellite the further east or west from the earth station s longitude Even though a satellite in theory can communi...

Page 30: ...est to news vehicle earth stations on the North American continent and Hawaii Using the 1705A for Satellite Communication The 1705A has two separate inputs one the L Band Input is specifically designed to work with LNB down converters which have an output signal range of 0 95 to 1 80 GHz This provides a means of looking at the signals from either Ku or C Band satellites The second input is identif...

Page 31: ...ency readout can be set so that the entire range of transponder frequencies can be read directly from the 1705A display As it is shipped from the factory the 1705A provides a readout in MHz for both bands However the 1705A has several customizing routines that can be used to tailor displays for ease of operation In particular the Readout Mode routine provides for frequency offset so that the frequ...

Page 32: ...al strength remain to be dealt with Each of the satellites has one or more singular characteristics In many cases the singular characteristics can be easily identified on the spectrum monitor which can save valuable setup time These characteristics can take the form of telemetry beacons transponder polarization schemes or blocks of non video signals that stand out And in a few cases the easiest me...

Page 33: ...ter Transponder Polarization Whether one or two polarizations are used can often be an easy way to identify a satellite For example a satellite with alternate polarization will have overlapping bandwidths similar to those depicted in Figure 1 7 In this example the center frequency of each transponder down link is given With the center frequency for each transponder known finding the correct transp...

Page 34: ... set up it is possible to directly zero in on the correct transponder Figure 1 8 is a computer simulation of the 1705A Spectrum Monitor display in FULL SPAN DIVISION Each division corresponds to 100 MHz If the satellite previously discussed is being looked at and the brightup is on the first marker then the first signal is transponder number 1 and the antenna feed horn is horizontally polarized Fu...

Page 35: ...output is at the up link frequency a 70 MHz monitoring point is often provided Sometimes the coupling of the IF signal between the exciter and Upconverter is a coaxial link that can be opened and a directional coupler installed for sampling purposes See Figure 1 9 NOTE The 70 MHz input is rated at 20 dBm maximum external pads may be required to meet this operating condition Once a directional coup...

Page 36: ... HPA antenna and transponder as a system can be made by comparing the exciter output using the 70 MHz input to the incoming signal from the down link using the L Band Input by simply switching between inputs See Figure 1 10 Miscellaneous Uses for the 1705A The 1705A Spectrum Monitor 70 MHz band covers a frequency range from 45 to 100 MHz at center screen The low VHF television channels and major p...

Page 37: ...PA OUT IN UP CONVERTER OUT VIDEO EXCITER 70 MHZ INPUT DIRECTIONAL COUPLER RECEIVER LNB L OUT Ku IN Ku BAND 14 GHZ Ku BAND 12 GHZ 3 dB SPLITTER L BAND 900 1450 MHZ Figure 1 10 1705A hooked up to look at either the output of the Video Exciter 70 MHz or the Receiver Input L Band ...

Page 38: ...Operating Instructions ...

Page 39: ......

Page 40: ...box surrounding the front panel label 1 VIDEO Turns on or off the Video Filter which reduces the post detection bandwidth video to reduce the high frequency components for display noise averaging A front panel LED indicator lights when the Video Filter is on Holding the Video switch activates the High Gain mode An on screen readout indicates 2 dB Div To exit this mode hold the switch again and the...

Page 41: ...EP SPEED CENTER FREQUENCY TRACE ROTATION 100 KHz 1 MHz MHz 10 FULL MENU SPAN DIV Tek REF 10 20 30 40 50 60 70 L O G f Figure 2 1 1705A front panel refer to text for descriptions of controls identified with circled numbers 4 SWEEP SPEED A variable control that sets the sweep repetition rate which is typically between 20 and 200 ms 5 CENTER FREQUENCY A ten turn variable control that determines the c...

Page 42: ...ed is dependent on the setting of the HORIZONTAL POSITION control 100 kHz Sets display span to 100 kHz per division Displays a maximum of 1 2 MHz for one full sweep The 1 MHz portion of the sweep that is displayed is dependent on the setting of the HORIZONTAL POSITION control MENU When both SPAN DIV switches are pressed simultaneously the normal display is replaced by the Main menu To exit the Mai...

Page 43: ...upply circuit board regardless of POWER switch state To totally remove shock hazard it is necessary to unplug the instrument and wait for the capacitors to discharge Rear Panel Connectors Signal input and power input are located on the 1705A rear panel See Fig ure 2 2 for the locations of the rear panel connectors 1 L BAND A 75Ω input f type connector used for the 900 2000 MHz input of L Band rf w...

Page 44: ...NLY WITH 250V 2A F TYPE L BAND INPUT LNB POW ER ON LNB POW ER OFF 18 VDC 250 mA ON Figure 2 2 1705A rear panel controls and connectors refer to text for descriptions of controls identified with circled numbers 3 LNB POWER Indicator LED indicator that lights when the 18 V supply is turned on and operating correctly Indicator will not light if the 18 V supply is shorted 4 70 MHz A 75Ω input bnc type...

Page 45: ...efer to a qualified service technician for troubleshooting If the Non Volatile RAM NVRAM is defective which disables the operation of the Microprocessor there is a crt readout If the 1705A comes on with the following message ERROR CANNOT READ OR WRITE TO 2444 PRESS VIDEO KEY TO EXIT operation will be questionable and the 1705A should be thoroughly checked out by a qualified service technician Norm...

Page 46: ...tom of the graticule There are two gain selections normal gain 10 dB div and high gain 2 dB div In normal gain mode major divisions are 10 dB which makes each minor division 2 dB When the GAIN front panel push button is held high gain is selected and major divisions are approximately 2 dB which makes minor divisions about 0 4 dB each Since dB is a dimensionless ratio and there are several scale va...

Page 47: ... 89 125 7943 282 4 0 1 585 2 512 40 0 100 000 10000 000 5 0 1 778 3 162 41 0 112 202 12589 254 6 0 1 995 3 981 42 0 125 893 15848 932 7 0 2 239 5 012 43 0 141 254 19952 623 8 0 2 512 6 310 44 0 158 489 25118 864 9 0 2 818 7 943 45 0 177 828 31622 777 10 0 3 162 10 000 46 0 199 526 39810 717 11 0 3 548 12 589 47 0 223 872 50118 723 12 0 3 981 15 849 48 0 251 189 63095 734 13 0 4 467 19 953 49 0 281...

Page 48: ... divided into ten major divisions which are further divided into five minor divisions each The horizontal scale corresponds to frequency with the lowest frequency to the left Note the arrow in Figure 2 4 that signifies that the frequency ascends toward the right Both the 60 and 80 dB lines are subdivided with minor division marks Traditionally many spectrum analyzer measurements and specifications...

Page 49: ...ximum frequencies when CENTER FREQUENCY is set to mid band Figure 2 6 shows frequencies associated with the graticule lines in FULL SPAN DIV when the CENTER FREQUENCY control is set to 1400 for L Band or 70 MHz for the 70 MHz Note also that the HORIZONTAL POSITION control affects the frequency to graticule scale resolution Determin ing where the HORIZONTAL POSITION control is set can easily be det...

Page 50: ...enter of the horizontal scale Center Frequency Readout The 1705A is equipped with alphanumeric readout for the CENTER FREQUEN CY This readout works in conjunction with a cursor In FULL SPAN DIV the cursor is actually a bright up zone on the trace See Figure 2 7 Actual position of the readout on the crt can be positioned to a location where it will not interfere with the measurements being made Tes...

Page 51: ...rted pyramid caret that is directly over the part of the sweep that corresponds to the setting of the front panel CENTER FREQUENCY control See Figure 2 8 Horizontal positioning affects the position of the cursor and the associated alphanumeric readout which is directly above the cursor The displayed location of the CENTER FREQUENCY can be displaced by up to 2 divisions from graticule center depend...

Page 52: ...2 8 1705A CRTwith the SCALE turned down to show the relationship between the alphanumeric readout and the front panel CENTER FREQUENCY tuning 1400 MHZ POINT ON THE TRACE THAT CORRESPONDS TO 1400 MHZ CENTER FREQUENCY TUNED AT THIS POINT Figure 2 9 The setting of the HORIZONTAL POSITION control can displace the location of the displayed center frequency ...

Page 53: ... the selection The Readout Position and Offset Adjust menus assign other functions to some of the front panel push button switches For these specific functions the names in brackets correspond to front panel switch names The selections for disabling enabling the crt readout are contained in the Readout Mode menu Readout is turned off by setting the displayed cursor next to the OFF selection and pu...

Page 54: ...igure 2 10 Using the 1705A menus Main menu is entered from the spectrum display by pressing both SPAN DIV buttons simultaneously NOTE The 1705A must be returned to the normal operating routine before the front panel push button switches perform the label functions Push the INPUT push button as many times as required to bring up the spectrum analyzer display The 1705A readout normally displays the ...

Page 55: ... for full end to end rotation See Figure 2 11 for an example of the display during Offset Adjust 12 00 GHZ Figure 2 11 An example of the readout displayed while satellite frequency is being set The is the same for both increasing and decreasing frequency When Offset is selected from the Readout Mode an additional auxiliary menu appears on screen for several seconds before it extinguishes and the s...

Page 56: ... push button as many times as required to bring up the spectrum analyzer display The series of tests that can be made are documented in Section 6 Maintenance under the sub section heading of General Troubleshooting Techniques Locating Ku Band Satellites The TEKTRONIX 1705A Spectrum Monitor is specifically designed to help the television news vehicle operator quickly and properly address a satellit...

Page 57: ...ted to the splitter feeding the L Band downlink signal from the outdoor Low Noise Block Converter LNB to the indoor receiver If the antenna is to be adjusted manually a portable ac or battery powered 1705A may be connected directly to the LNB at the antenna in which case the spectrum monitor can be used to power the LNB Table 2 3 Azimuth Elevation Table for 21 CONUS Cities CITY SATCOM K2 G STAR II...

Page 58: ... data carriers on many transponders will identify Satcom K 2 Other satellites will have similar identifying characteristics If the incorrect satellite has been selected repoint the antenna to locate the desired satellite Once any satellite is found and identified a reference point is established and nearby satellites may be located by moving the antenna carefully in the proper direction 8 Optimize...

Page 59: ...eck will only take seconds This check may be permitted earlier in the day if time is available and the antenna or transmitter setting are not to be changed 11 During transmit the 1705A may be used to verify the presence of video audio and any communications signals at the 70 MHz output of the Video Exciter This signal may be permanently connected to the 1705A along with the L Band receive connecti...

Page 60: ...are for use only by qualified personnel To avoid injury do not perform any servicing other than that stated in the operating instructions unless you are qualified to do so Refer to all safety summaries before performing any service WARNING ...

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Page 62: ...Installation ...

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Page 64: ... have both current carrying conductors live with respect to ground such as phase to phase in multiphase systems are not recommended as power sources The 1705A operates over a frequency range of 48 to 66 Hz at any mains voltage between 90 Vac and 250 Vac These newer versions of the 1705A instruments do not require any internal changes to select their operating voltage range The slide switch located...

Page 65: ...the power supply may go out of regulation when mains voltage falls below 100 V The 1705A provides an internal jumper setting to enable or disable the graticule lights See Table 3 1 Table 3 1 Internal Jumper Selection Jumper Name Position Function A3A1 J100 Light Enable 1 2 2 3 Graticule lights enabled factory set Graticule lights disabled Mechanical Installation NOTE Cabinet drawings are provided ...

Page 66: ...ur feet a flip up stand and has different hole sizes and spacing than the 1700F00 See Figure 3 3 All of the 1700 Series metal cabinets available from Tektronix as Optional Accessories provide the proper electrical environment for the instrument supply adequate shielding minimize handling damage and reduce dust accumulation within the instrument REAR 6 130 BOTTOM SIDE 12 725 8 250 6 875 0 688 1 060...

Page 67: ... 8 250 in Figure 3 3 1700F02 portable cabinet dimensions WARNING Do not attempt to carry a cabinetized instrument without installing the mounting screws There is nothing to hold the instrument in the cabinet if it is tipped forward The instrument is secured to the cabinet by two 6 32 PozidriveǺ screws located in the upper corners of the rear panel See Figure 3 4 Cabinetizing ...

Page 68: ... consists of two attached cabinets It can be used to mount the 1705A and another half rack width instrument in a standard 19 inch rack CAUTION Be sure to read and follow the instructions that are shipped with the rack adapter Use the correct sleeve for your product The ventilation holes and EMI shielding on the sleeves are specially designed to meet the requirements of the instruments for which th...

Page 69: ...ck alignment Rear view 6 875 Mounting holes Figure 3 5 The WFM7F05 side by side rack adapter The rack adapter is adjustable so the instrument can be more closely aligned with other equipment in the rack See Figure 3 5 WFM7F05 1700F06 Figure 3 6 A WFM7F05 with a blank front panel 1700F06 ...

Page 70: ...igure 3 6 The rack adapter and panel are available through your local Tektronix field office or representative When only one instrument is mounted in the side by side adapter an accessory drawer 1700F07 can be installed in the blank side of the cabinet See Figure 3 7 1700F07 WFM7F05 Figure 3 7 WFM7F05 rack mount cabinet with a 1700F07 utility drawer ...

Page 71: ...shelf For Flush Front Panel Cut hole the same size as the monitor front molding to allow the monitor front panel to align with the custom panel surface For Protruding Front Molding Cut hole in panel the same size as the opening in the monitor cabinet to al low the front panel molding to cover the hole Figure 3 8 Considerations for custom installation of an instrument To mount the 1705A safely atta...

Page 72: ...Theory of Operation ...

Page 73: ......

Page 74: ... in FULL SPAN DIV on the crt In the magnified SPAN DIV ranges the frequency readout is the approximate frequency under the readout marker Front panel mode switching is accomplished by push button switches whose status is constantly polled by a microprocessor In turn the microprocessor controls switching functions and circuit gains so that the instrument can be used to locate or monitor a specific ...

Page 75: ...utput A three sec tion helical resonator is used for the 130 5 MHz IF filter An additional band pass crystal filter centered at 10 7 kHz with a 10 kHz bandwidth can be added by front panel selection to provide narrow resolution The 300 kHz bandwidth filter is always in the circuit regardless of the front pa nel RESOLUTION selection Maximum bandwidth of the 1705A is 300 kHz The resolution filters d...

Page 76: ... measurement and diagnostic routines is the controlling element of the 1705A A Non Volatile Random Access Memory NVRAM provides a method to store the current front panel switch settings at power down so that the 1705A can come back up with the last front panel setup CENTER FREQUENCY readout data is converted to digital data by an Analog to Digital Converter and then input into the microprocessor R...

Page 77: ... totally shielded The L Band Tuner is also self contained totally shielded and contains no user ser viceable parts The L Band signal 900 1750 MHz is input directly to a tuner subassembly that contains the Tuned RF Amplifier mixer and Voltage Controlled Oscillator VCO required to produce the first Intermediate Frequency IF of 489 9 MHz The 489 9 MHz 1st IF signal is cabled to the Main board The tun...

Page 78: ...ed by the instantaneous level of the pre corrected ramp from the Sweep Generator Diagram 3 The center tap of T187 is the LO output providing an amplitude of approximately 7 dBm Q20 and Q21 form a switching circuit that turns off the VCO when the L Band input is selected When LBAND goes low Q21 is shut off causing Q20 to unsaturate and disconnect the 11 8 V from the VCO The 70 MHz tuner assembly A5...

Page 79: ...ert a signal at the 2nd IF frequency The 10 7 MHz 2nd IF signal passes through the 300 kHz Resolution filter or a combination of the 10 kHz and the 300 kHz Resolution filters The switching of filters is accomplished by a combination of a control signal 10KHZ from the microprocessor Diagram 5 and a switching network consisting of U23D E and F Q9 and Q10 and switching diodes CR22 23 25 26 27 28 29 a...

Page 80: ...n the Z Axis control to provide retrace blanking CR21 limits the output swing in the negative direction to 0 7 volts The Ramp Generator output U24B pin 7 drives the Horizontal Deflection Amplifier and the Gain Control SPAN DIV switching U20 Each switch in U20 selects a different value of Ri for operational amplifier U18A The gain is maximum at FULL 50 MHz per division and minimum at 100 kHz per di...

Page 81: ...PAN DIV When the SPAN DIV is set at FULL the output of U14A positions the bright up zone to correspond to the frequency displayed by the readout The output of U14B provides a voltage that offsets the ramp at the output of U14C In the FULL setting of SPAN DIV U17D an analog switch is closed and U14C provides a gain of 10 to both the ramp from U24B and the offset from U14B The bright up zone is gene...

Page 82: ...FULL SPAN the trace is brightened for the marker In any other SPAN DIV setting the trace is of uniform brightness when the output of U14D is near 0 V a pulse that produces the crt bright zone is generated by the Z Axis Control circuit The readout intensity is controlled separately by Q4 and Q5 If the RO BLANK control line is active low Q4 is turned off and Q5 is turned on When Q5 is on the current...

Page 83: ...ugh a Digital to Analog Converter DAC Diagram 5 The vertical positioning signal from the front panel VERTICAL POSITION control is applied to the readout in order to common mode out positioning effect when the trace is repositioned The vertical output signal or the Y Axis readout drives the base of Q26 one side of a differential input amplifier The other side Q28 is driven by the positioning voltag...

Page 84: ...he crt readout is output through Line 7 U2 pin 8 The Center Frequency Readout data from U1 the readout ADC is input through Line 5 also U2 pin 6 U1 is an A to D Converter ADC with successive approximation register It is used to convert the analog voltage level from the front panel CENTER FREQUENCY control to a digital signal for the microprocessor and the Readout Digital to Analog Converter DAC R4...

Page 85: ...ustment Q3 and Q100 provide a current source for the graticule lights Base voltage which controls the amount of current flowing in the light circuit is set by the front panel SCALE control Jumper J100 on the Graticule Light board allows the graticule lights to be disabled Front Panel Diagram 6 The front panel schematic shows all of the operational controls for the instru ment including potentiomet...

Page 86: ...k to prevent the IC from oscillating 40V 40V 40V 18V 18V 18V 0 7V 0 7V 0 7V LOW LOAD AVERAGE LOAD HIGH LOAD Figure 4 2 Output duty cycle of the pulse width modulator used in the 18 V Power Supply Q481 and Q482 drive the switching transistor Q482 provides forward base current to the switching transistor Q596 Q483 provides reverse base current to effectively turn off Q596 Q596 operates with voltage ...

Page 87: ...put is shorted the light will extinguish Low Voltage Power Supply Diagram 7 The Low Voltage Power Supply converts the mains line voltage 90 250 Vac to supply the power requirements of the instrument The voltages supplied by the Low Voltage Power Supply are 40 V 15 V and 5 V The Low Voltage Power Supply is called a Flyback Switcher When switcher mosfet Q9 is turned on its drain voltage drops to app...

Page 88: ... mode PWM uses two feedback loops The inner current feedback loop directly controls the switcher mosfet peak current The outer voltage feedback loop programs the inner loop peak current trip point U5 pin 2 is the inverting input of an internal op amp The non inverting input is set to 2 5 V by an internal voltage reference Current from the peak detector flows through R83 and R79 R84 provides a 100 ...

Page 89: ...ershoot of the 5 V at power up R98 and CR26 provide a minimum operating current for VR1 R68 decouples C39 from VR1 Overvoltage protection for the 5V supply is provided by a crowbar circuit formed by Q11 VR3 R13 and R14 The 80 kHz sawtooth waveform at U3 pin 3 trips comparator U3 U3 pin 1 then feeds a trigger pulse to one shot U4 U4 pin 13 outputs a 300 nS pulse to the 130 mA current source consist...

Page 90: ...urrent to Q6 The 100 V output is regulated directly while the High Voltage Power Supply is indirectly regulated through a current feedback circuit R48 C16 R60 and R64 form the High Voltage Power Supply current feedback circuit As the current from the High Voltage Power Supply is increased the voltage to the side of the Error Amplifier U2 increases which increases the base drive to Q6 the HV Osc Th...

Page 91: ...esent at the cathode of CR8 is input to the Grid Drive circuit where it is clipped for use as the crt control grid bias The sine wave from the cathode of CR8 is coupled through R47 to a clipping circuit consisting of CR5 and CR6 Clipping level for the positive excursion of the sine wave is set by the CRT Bias adjustment R58 The negative clipping level is set by the front panel INTENSITY control th...

Page 92: ...tor C6 speeds up the amplifier by coupling ac signals to the base of Q3 CR2 and R41 protect the amplifier during crt arcing The pinout for the CRT is shown in Figure 4 3 Pin Description 1 Filament f 2 Cathode k 3 GRID g1 4 FOCUS g3 5 ASTIG g4 6 GEOM g5 7 VERT PLATE y2 9 VERT PLATE y1 11 HORIZ PLATE x2 12 1st ANODE g2 13 HORIZ PLATE x1 14 Filament f 14 13 12 11 9 7 6 5 4 3 2 1 Figure 4 3 Pinout of ...

Page 93: ...Theory of Operation 4 20 1705A Spectrum Monitor ...

Page 94: ...Checks and Adjustments ...

Page 95: ......

Page 96: ...tion are guides to adjustments and checks They are not instrument specifications except when listed in the Performance Requirement column of the Specification Tables in Section 1 of this manual Recommended Equipment List The following equipment and accessory items are required to do the Performance Check and or Adjustment Procedures Broad specifications are followed by a piece of equipment that me...

Page 97: ...more and flatness within 3 dB over the frequency range Accurate step attenuator calibrated in dB 0 to 60 For example A TEKTRONIX TR502 Tracking Generator and associated equipment a Wavetek Model 3520 or a Hewlett Packard 8614A Signal Generator with 8496A Attenuator 110 dB 6 Variable Autotransformer For example General Radio Metered Auto Transformer W10MT3W If 220 volt operation must be checked a c...

Page 98: ...ble of contents 1 Preliminary Setup a Connect autotransformer b Connect markers from Comb Generator 2 Check Power Supply Operation d CHECK for stable operation over the prescribed voltage range 3 Check LNB Power Supply c CHECK that the rear panel red indicator lamp is lighted and that the DVM reads 18 V 0 9 V e CHECK that the red indicator lamp extinguishes and then comes back on when the short is...

Page 99: ...change i CHECK that the tip of the marker is on the crt center line 1 minor Division vertically 8 Check Video Filter d CHECK that the baseline noise amplitude drops approximately 50 when the VIDEO FILTER is ON 9 Check Sweep Speed b CHECK for a solid trace with almost no flicker d CHECK for approximately 3 to 4 sweeps per second Alternate Method e CHECK for a ramp duration of 20 ms 10 ms h CHECK fo...

Page 100: ... CHECK that the tip can be positioned 2 Divisions left and right of center e CHECK that the marker tip can be positioned 3 Divisions down from its present position f CHECK that the baseline can be positioned to the 30 graticule line 14 Check 2 dB Div Gain g CHECK for more than 1 Division of amplitude change h CHECK that the noise floor can be positioned on screen 1 Preliminary Setup a Connect the ...

Page 101: ...R ON INTENSITY Set to Preference FOCUS SCALE VERTICAL POSITION Set later HORIZONTAL POSITION INPUT 70 MHz RESOLUTION 300 kHz VIDEO off SPAN DIV FULL CENTER FREQUENCY anywhere SWEEP SPEED y SG503 Comb Generator VARIABLE AUTOTRANSFORMER 70 MHz INPUT 1705A Figure 5 1 Initial equipment connections ...

Page 102: ...If the LNB POWER is on and in use the requirement is derated to 100 132 V or 200 250 V e Return the autotransformer to the local nominal mains voltage 3 Check LNB Power Supply REQUIREMENT 18 Vdc 5 a Connect DVM leads between the center conductor of the L BAND INPUT connector and ground b Turn on the LNB POWER switch c CHECK that the rear panel LNB POWER LED is ON and that the DVM reads 18 V 0 9 V ...

Page 103: ...ep d CHECK that each marker is within 1 minor Division of a major graticule line when the 2nd marker is on the left edge of the graticule see Figure 5 2 5 Check 70 MHz SPAN DIV and Readout REQUIREMENT One marker per 5 Divisions 1 Division Readout accuracy L Band 20 MHz 70 MHz 2 MHz a Select 1 MHz SPAN DIV b Set the CENTER FREQUENCY to read 70 MHz c Center the readout caret horizontally on screen d...

Page 104: ...plitude to 0 5 42 dBm h Set the 1705A SPAN DIV to FULL and the CENTER FREQUENCY to read 45 MHz Check to see that the marker is intensified i Set the 1705A SPAN DIV to 1 MHz and check that the marker is on screen j Position the marker under the readout caret with the CENTER FRE QUENCY control k CHECK that readout reads 45 1 count l Set SPAN DIV to 100 kHz m CHECK that the marker is on screen n Repe...

Page 105: ...7 Check 70 MHz Gain and Flatness REQUIREMENT Incremental Amplitude Accuracy 4 dB 70 MHz Flatness 1 minor Division from 70 MHz to either 50 or 90 MHz a Set SPAN DIV to FULL b Set RESOLUTION to 300 kHz c Set SWEEP SPEED fully clockwise d Set the leveled sine wave generator Frequency to 70 MHz the Ampli tude Multiplier to X1 and the Amplitude to 0 5 2 dBm e CHECK for a marker amplitude change of 2 Di...

Page 106: ...ENT Typically 20 200 ms a Verify that SPAN DIV is set to FULL and that SWEEP SPEED is set fully clockwise b CHECK for a solid trace with almost no flicker c Set SWEEP SPEED fully counterclockwise d CHECK for about 3 to 4 sweeps per second e Return SWEEP SPEED fully clockwise Alternate Method a Connect the oscilloscope 10X probe to W2 b Set the oscilloscope timebase to 5 ms Div c Set the oscillosco...

Page 107: ...TOTRANSFORMER L BAND INPUT 1705A Figure 5 4 Equipment connections for L Band checkout b Set the leveled sine wave generator Frequency to 100 MHz Amplitude Multiplier to X1 and the Amplitude to 1 5 8 dBm c Set the 1705A INPUT to L BAND d Set the SPAN DIV to FULL e CHECK for 10 frequency markers Ignore any sweep start marker f CHECK that each marker is within one minor Division of a major graticule ...

Page 108: ...REQUIREMENTS FULL 1 marker Division 1 minor Division 10 MHz 1 marker 5 Divisions 1 Division 1 MHz 1 marker 5 Divisions 1 Division Readout Accuracy 20 MHz a Set CENTER FREQUENCY to 1400 MHz and set SPAN DIV to 10 MHz b Set the leveled sine wave generator Frequency to 50 MHz c Position the readout caret to center of screen horizontally d CHECK for 1 marker every 5 Divisions 1 Division adjust CENTER ...

Page 109: ...05A L BAND INPUT l Connect the UHF signal generator output to the 1705A L BAND INPUT See Figure 5 6 VARIABLE AUTOTRANSFORMER L BAND INPUT UHF SINE WAVE GENERATOR 1705A Figure 5 6 Using the UHF Signal Generator to check L Band Span Division Readout Gain and Flatness m Set the UHF signal generator Amplitude to 50 dBm and Frequency to 1000 MHz n Set the 1705A SPAN DIV to FULL Dial the CENTER FREQUENC...

Page 110: ...ED fully counterclockwise c Set the UHF signal generator Frequency to 1400 MHz and Amplitude to 30 dBm Position the tip of the marker to the 10 graticule reference line vertical scale d Change the UHF signal generator Frequency to 950 MHz e CHECK that the marker is on the same crt center line vertically 0 5 Division f Change the UHF signal generator Frequency to 1700 MHz g CHECK that the marker is...

Page 111: ...hange while changing from 50 dBm to 53 dBm a Set the UHF signal generator Frequency to 1400 MHz and Amplitude to 50 dBm b Hold the VIDEO push button until 2 dB Div appears on the crt readout c Use the CENTER FREQUENCY control to locate the 1400 MHz marker d Select 100 kHz SPAN DIV Using CENTER FREQUENCY and VERTICAL controls check that the marker tip can be positioned on screen e Return to FULL SP...

Page 112: ...rder as the longer form of the procedure so the Short Form Procedure can be used as an index for the Long Form Circuit numbers for parts adjusted in the step are also included with the step title A1 POWER SUPPLY BOARD 1 Adjust 5 V R99 2 Adjust CRT Bias R58 3 Adjust Geometry R45 Center Focus R11 and Astigmatism R49 4 Adjust Trace Rotation A3 MAIN BOARD 5 Adjust On Board Regulated Power Supplies R99...

Page 113: ...ord to the variable autotransformer Turn the 1705A power on Set the front panel controls to start this procedure as shown in Table 5 2 Table 5 2 Preliminary Control Settings POWER ON INTENSITY Set to Preference FOCUS SCALE VERTICAL POSITION Set later HORIZONTAL POSITION INPUT 70 MHz RESOLUTION 300 kHz VIDEO ON SPAN DIV FULL CENTER FREQUENCY anywhere SWEEP SPEED y A1 POWER SUPPLY BOARD Refer to Fig...

Page 114: ...shed c Set INTENSITY control for a useable display CAUTION MAINS VOLTAGE A1 PWR SPLY BD R11 R45 R49 R58 W1 5V CRT BIAS ASTIG GEOM FOCUS W4 15V W3 15V A3 MAIN BD FRONT R99 R111 L4 FL1 C69 J11 FL2 C52 C64 C62 R175 R176 R232 R239 R240 W12 W11 R168 R140 R113 R89 W8 R27 R29 R55 R56 R57 W5 W2 R48 R49 R4 R36 R37 R38 R61 R35 R82 R51 R58 R75 R81 5V ADJ R99 Figure 5 7 Adjustment locations ...

Page 115: ...button to display the DAC test pattern d Set the front panel FOCUS control so that it is approximately at the center of its rotation e ADJUST R45 GEOM for 35V 1V at pin 1 of J3 f ADJUST R11 CTR FOCUS and R49 ASTIG for the most clearly defined DAC test pattern See Figure 5 8 Tek REF 10 20 30 40 50 60 70 L O G f Figure 5 8 DAC check waveforms used to check Focus Astigmatism Geometry and setting of t...

Page 116: ...panel LNB POWER switch ground lug and the active lead to the 11 8 V test point W8 See Figure 5 7 b ADJUST R99 11 8 V ADJ for 11 8 V 11 78 to 11 82 V c Connect the voltmeter active lead to the 11 8 V test point W9 See Figure 5 7 d ADJUST R111 11 8 V ADJ for 11 8 V 11 78 to 11 82 V 6 Adjust Horizontal Gain a Connect a shorting strap between W11 and W12 See Figure 5 9 W11 W12 SHORTING STRAP Figure 5 ...

Page 117: ...button twice to return to a normal display 8 Adjust 360 119 8 MHz L O NOTE Use an insulated tool for the following adjustments a Adjust the VERTICAL POSITION control so that the crt trace is on the 70 graticule reference line b Connect the signal generator to J11 480 MHz IF Input Set the output Frequency for 489 7 MHz and the Amplitude to 40 dBm c Select 300 kHz RESOLUTION d Set C55 to full mesh C...

Page 118: ...M to W2 See Figure 5 7 f Set the 1705A SPAN DIV to FULL g ADJUST R113 FULL GAIN to match the reading from part d 10 Adjust 70 MHz Band Linearity a Set SWEEP SPEED fully clockwise SPAN DIV to 1 MHz and adjust the HORIZONTAL POSITION to place the caret on the center graticule b Set the SPAN DIV to FULL c Connect the signal generator output to the 1705A 70 MHz INPUT d Set the signal generator Frequen...

Page 119: ...he screen and set RESOLUTION to 10 kHz d ADJUST C52 C62 and C64 for a tall symmetrical signal 6 Divisions e Set RESOLUTION to 300 kHz and turn SWEEP SPEED fully counterclockwise f ADJUST R175 to match the signal amplitude of the highest point of the 300 kHz filtered marker with the tip of the 10 kHz filtered marker while switching between 10 kHz and 300 kHz RESOLUTION 12 Adjust L Band Linearity a ...

Page 120: ...sition any marker under the readout caret c Set SPAN DIV to 10 MHz d ADJUST R27 Horiz Posn Readout to position the caret directly over the marker e Set SPAN DIV to 1 MHz Marker should be under caret 1 minor Division f Adjust the HORIZONTAL POSITION control to place the caret at the center of the screen g If R27 requires adjustment check step 10 parts a through e R55 and check step 12 parts a throu...

Page 121: ... MHz and Amplitude to 30 dBm c Adjust the CENTER FREQUENCY control so the readout displays 1400 MHz d ADJUST R61 to center the intensified zone on the 1400 MHz marker e Set the leveled sine wave generator Frequency to 1000 MHz f Turn the CENTER FREQUENCY control counterclockwise to 1000 MHz g ADJUST R36 to center the intensified zone on the 900 MHz marker h Repeat this step until the intensified z...

Page 122: ... down again to exit the 2 dB Div mode 19 Adjust 590 MHz Notch a Select L BAND INPUT and set the SPAN DIV to 10 MHz b Connect the signal generator to the L BAND INPUT c Set the signal generator Frequency to 1200 MHz and Amplitude to 20 dBm d Use the HORIZONTAL POSITION control to place the 1200 MHz signal at the extreme left graticule mark A small spur should be visible near the extreme right grati...

Page 123: ...Checks and Adjustments 5 28 1705A Spectrum Monitor ...

Page 124: ...Maintenance ...

Page 125: ...Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 FAX 781 665 0780 TestEquipmentDepot com ...

Page 126: ...rosion under humid conditions The rosin residue if left alone does not exhibit these corrosive properties The instrument should be cleaned often enough to prevent dust or dirt from accumulating Dirt acts as a thermal insulating blanket that prevents effective heat dissipation and can provide high resistance electrical leakage paths between conductors or components in a humid environment Exterior C...

Page 127: ...isible defects is obvious however if heat damaged parts are discovered determine the cause of overheating before replacing the damaged part to prevent additional damage Periodic checks of the transistors and integrated circuits are not recommended The best measure of performance is the actual operation of the component in the circuit This instrument contains electrical components that are suscepti...

Page 128: ... by the body never by the leads 7 Do not slide the components over any surface 8 Avoid handling components in areas that have a floor or work surface covering capable of generating a static charge 9 Use a soldering iron that is connected to earth ground 10 Use only special antistatic suction or wick type desoldering tools Instrument performance should be checked after each 2000 hours of operation ...

Page 129: ...EO SPAN SPAN INPUT SPAN DIV Figure 6 1 Using the 1705A menus Main menu is entered from the spectrum display by pressing both SPAN DIV buttons simultaneously Diagnostic Routines Diagnostics are addressed by pushing both SPAN buttons at the same time which brings up the Main menu on the crt screen Figure 6 1 shows the Main menu and all of the submenus In addition to the Test routine there are operat...

Page 130: ... a message that gives the memory version and copyright dates The test then proceeds to check the NOVRAM and the Electrically Eraseable Programmable Memory EEPROM The test goes through three steps each with its own message displayed on the crt starting with NONVOLATILE 2444 RAM TEST Its first action is to write to and read out of memory during this step there is a message that the microprocessor is...

Page 131: ... U809 and associated components Once the NOVRAM test is successfully completed there will be an acknowledg ing crt display See Figure 6 3 END OF NON VOLATILE 2444 RAM TEST 2444 TEST GOOD PRESS INPUT KEY TO EXIT Figure 6 3 1705A CRT display when the NOVRAM Test has been successfully completed There is a special case that can occur In normal operation the 1705A front pa nel setup should be stored wh...

Page 132: ...test is used to test the readout capability crt geometry and focus and provides a convenient method of determining if Trace Rotation needs to be adjusted Figure 6 5 shows the waveform superimposed over the crt graticule to demon strate its value as an adjustment tool The DAC test is selected from the Test Auxiliary menu by pushing the 1705A RESOLUTION push button The test in progress is exited any...

Page 133: ... both cases the test is terminated by pressing the INPUT push button Troubleshooting Aids Since this manual is also a troubleshooting aid its organization is described here This material is general and does not cover specific cases The foldout pages at the back of the manual contain block and schematic diagrams circuit board illustrations and lookup charts Diagrams Schematic diagrams show the circ...

Page 134: ...g The circuit board assemblies are assigned assembly or A numbers Figure 6 6 shows the circuit board assembly locations for this instrument A2 FRONT PANEL BOARD A3 MAIN BOARD A1 POWER SUPPLY BOARD A4 18V SUPPLY BOARD A5 70MHZ TUNER A6 TUNER Figure 6 6 Circuit board assembly locations There are two separate parts lists in this manual The Replaceable Electrical Parts list precedes the schematic diag...

Page 135: ...symbol is used to identify pin 1 on the circuit board and the connector to assist in aligning the connector with correct square pins Figure 6 7 shows the numbering scheme and the triangular marking on the connector and the marking on the etched circuit board A pin replacement kit including necessary tools instructions and replacement pins is available from Tektronix Inc Contact a Tektronix field o...

Page 136: ...s capable of destroying components Circuit board mounted pins PIN 1 Moveable 10 pin plug Square pin connector on power supply circuit board PIN 1 PIN 1 24 and 34 pin circuit board connectors on Main circuit board ROW A ROW B ROW B ROW A Figure 6 7 Multiple pin connectors used in the 1705A Spectrum Monitor CAUTION Always remove the assembly from the instrument prior to attempting to replace a solde...

Page 137: ...tinuing If the repair is minor such as replacing a component see the parts list for replacement information Removal and replacement procedures for the assemblies can be found under Corrective Maintenance Power Supply Troubleshooting Procedure NOTE A review of the power supply theory of operation is recommended before attempting repairs The equipment needed to troubleshoot the power supply H Digita...

Page 138: ...nd loaded Low Volts Supply will output the voltages listed in Table 6 3 Use the DMM to measure the voltages between TP1 and the voltage test points If the supply is not regulating properly continue with the procedure Table 6 3 Low Volts Supply Voltages Test Point Voltage W1 5 V 4 88 to 5 12 V W4 15 V 14 0 to 16 0 V W3 15 V 14 0 to 16 0 V W2 40 V 39 0 to 41 0 V NOTE The Low Volts Power Supply troub...

Page 139: ... 3 Output Check a Connect the negative output from the 20 Vdc Power Supply to TP1 Connect the positive output to W4 15 V The circuit should draw less than 20 mA Excessive current draw can be caused by CR11 or U2 High Volts Power Supply b Connect the negative output from the 20 Vdc Power Supply to TP1 Connect the positive output to W2 40 V The circuit should draw less than 20 mA Excessive current d...

Page 140: ...or Amplifier Check a Connect the negative output from the variable DC Power Supply to TP1 Connect the positive output to W1 5 V b Connect the negative output of another variable DC Power Supply to TP1 Connect the positive output to W4 15 V Set the variable power supply to 20 Vdc c Connect the digital multimeter between TP1 and the cathode of CR15 d Set the variable DC Power Supply connected to W1 ...

Page 141: ... multimeter measure the voltage between TP1 and the collector of Q1 It should be approximately 140 V Reconnect the lifted end of R24 Z Axis Amplifier Check Unsolder and lift one end of R8 Power up the Power Supply Using the digital multimeter measure the voltage between TP1 and the collector of Q4 It should be approximately 10 V Short together the base and emitter of Q5 The collector of Q4 should ...

Page 142: ...oints Circuit Location Voltage T1 pin 4 Approximately 40 V T1 pin 13 Less than 2 V U2 pin 2 Approximately 4 8 V U2 pin 6 4 to 11 V CR9 cathode Approximately 100 V CRT Voltage Check NOTE This check requires a high voltage probe having an input resistance of 1 GΩ or more Connect the high voltage probe ground to TP1 Load the Low Volts Supply with the instrument or with a 20Ω 2 watt resistor loading t...

Page 143: ...ugh local sources Using a local source where possible will eliminate shipping delays Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available and to improve circuit performance Therefore it is important to include the following information when ordering parts 1 Part Number 2 Instrument Type or Number 3 Serial Number 4 Modification or Option Nu...

Page 144: ... instrument be sure to disconnect the power cord CAUTION Do not reinsert screws in the rear panel when the instrument is removed from the cabinet NOTE All screws unless otherwise noted are TORXǺ screws and can be removed with a T15 screwdriver tip Tektronix part number 003 0966 00 The exception is 2 PozidriveǺ screws which can be removed with a 1 PozidriveǺ tip 003 0443 00 Do not reinsert screws i...

Page 145: ...strument as Standard Accessories Additional bulbs can be purchased from Tektronix see Replaceable Electrical Parts list or from local electronics distribution sources Procedure 1 Remove the bezel according to the preceding instructions 2 To remove a bulb position the tweezer tips on the thin flat portion of the bulb close to the plastic socket Carefully pull the bulb straight out 3 To install a bu...

Page 146: ...ugh the hole in the Main board CAUTION Avoid bending the crt base pins when pushing the crt into the socket 3 Slide the CRT into the instrument guiding the rubber manchet on the end of the shield into the rear CRT support 4 Align the socket on the A10 CRT Socket board with the pins and key on the CRT Gently push the CRT and the socket board together until the CRT pins are fully seated in the socke...

Page 147: ... 333 3990 01 Figure 6 9 Screws securing the rear panel 1 Remove the five rear screws See Figure 6 9 Screws securing the power receptical use removeable nuts as fasteners inside the rear panel 2 Unsolder the bnc and ground connections If 1700F10 Field Upgrade is installed unsolder leads from the battery connector 3 Unsolder the two leads to the 18 V switch 4 Remove the hex nut on the L BAND INPUT c...

Page 148: ... slipping it through the front panel opening 4 To access the Front Panel board components a Remove the knobs from the front b Remove the four screws from the rear c The board should now separate from the front panel making the components accessible 1 Unsolder the five wires from the tuner 2 Unplug the phone jack from the tuner 3 Remove the rear panel L BAND INPUT connector hex nut See Fig ure 6 11...

Page 149: ... upward until the L BAND INPUT connector is clear of the rear panel 1 Unsolder the three wires from the feed through capacitors at the back of the 70 MHz tuner 2 Unplug the coax connector from the rear of the 70 MHz tuner 3 Remove the 70 MHz tuner cover It is held on by six screws See Fig ure 6 11 4 Turn the 1705A on its left side crt down and remove the two screws that secure the 70 MHz tuner to ...

Page 150: ...e rest of the steps 1 Remove the plug from A1J4 on the Power Supply board the connection to the Main board WARNING The crt may retain a dangerous charge Ground the conductor of the anode to discharge the crt Do not allow the conductor to touch your body or any circuitry 2 Remove the anode connection from the crt and discharge it to ground 3 Remove the plugs from J1 and J3 the crt wires Remove the ...

Page 151: ...g the procedure BESCHLEUNIGUNGSSPANNUNG KLEINER ALS 20kV DIE IN DIESEM GERAT ENTSTEHENDE RONTGENSTRAHLUNG IST AUSREICHEND ABGESCHIRMT TO AVOID ELECTRICAL SHOCK THE POWER CORD PROTECTIVE GROUNDING CONDUCTOR MUST BE CONNECTED TO EARTH GROUND SPECTRUM MONITOR 70 MHz INPUT L BAND INPUT LNB POWER LNB POWER ON OFF 18VDC 250mA ON WARNING 0 70 MAX 50 60Hz 90 250V REPLACE FUSE ONLY WITH 250V 2A F TYPE 333 ...

Page 152: ...ervice required If possible save and reuse the package in which your instrument was shipped since this will provide maximum protection See Figure 6 14 If the original package is unfit for use or not available repackage the instrument as follows Figure 6 14 Repackaging a 1705A instrument 1 Use a shipping carton of corrugated cardboard with a test strength of at least 275 pounds and inside dimension...

Page 153: ...m Monitor 3 Cushion the instrument on all sides by tightly packing dunnage or urethane foam between the carton and the instrument Allow 3 inches on all sides for cushioning 4 Seal the carton with shipping tape or industrial stapler ...

Page 154: ...Options ...

Page 155: ......

Page 156: ...0V 10A A4 North American 250V 18A A5 Swiss 240V 6A All power cords include captive power plug and one replacement fuse Unless otherwise specified power cords for use in North America are UL listed and CSA certified Option cords are approved by at least one test house acceptable in the country to which the product is shipped Power cord part numbers are shown on the pull out in Section 10 Field Upgr...

Page 157: ...sed to mount the 1705A and another half rack width instrument in a standard 19 inch rack Blank Panel 1700F06 When only one side of a 1700F05 dual rack adapter is used this blank panel can be installed in the other half to improve appearance and protect air flow Utility Drawer 1700F07 When only one side of a 1700F05 dual rack adapter is used an alternate to the 1700F06 blank panel is the 1700F07 ut...

Page 158: ...Replaceable Electrical Parts ...

Page 159: ......

Page 160: ...ocal Tektronix Inc Field Office or representative will contact you concerning any change in part number Change information if any is located at the rear of this manual Using the Replaceable Electrical Parts List The tabular information in the Replaceable Electrical Parts list is arranged for quick retrieval Understanding the structure and features of the list will help you find all of the informat...

Page 161: ...ociated electrical part for example fuse holder follows fuse Chassis mounted parts and cable assemblies have no assembly number prefix and are located at the end of the electrical parts list Indicates part number to be used when ordering replacement part from Tektronix Column three 3 indicates the serial or assembly number at which the part was first used Column four 4 indicates the serial or asse...

Page 162: ...7014 NATIONAL SEMICONDUCTOR CORP 2900 SEMICONDUCTOR DR SANTA CLARA CA 95051 0606 31918 ITT SCHADOW INC 8081 WALLACE RD EDEN PRAIRIE MN 55344 2224 33095 SPECTRUM CONTROL INC 2185 W WEIGHT ST ERIE PA 16505 34361 OMRON ELECTRONICS INC SUNNYVALE CA 37942 NORTH AMERICAN CAPACITOR CO INDIANAPOLIS ROAD HWY 240 GREEN CASTLE IN 46135 1 MALLORY DIVISION PO BOX 240 51406 MURATA ERIE NORTH AMERICA INC 2200 LA...

Page 163: ...A KANAGAWA 228 JAPAN TK1462 YAMAICHI ELECTRONICS CO LTD 3 CHROME SHIBAURA TOKYO JAPAN 2ND FLOOR NEW KYOEI MINATO KU BLDG 17 11 TK1573 WILHELM WESTERMAN PO BOX 2345 6800 MANNHEIM 1 WEST GERMANY AUGUSTA ANLAGE 56 TK1884 ROGERS CORPORATION 5750 EAST MCKELLIPS RD MESA AZ 85205 Q PAC DIVISION TK1913 WIMA 2269 SAW MILL RIVER ROAD ELMSFORD NY 10523 THE INTER TECHNICAL GROUP IND PO BOX 127 ...

Page 164: ...281 0707 00 A1C13 281 0707 00 CAP FXD CER DI 15000PF 10 200V 80009 281 0707 00 A1C14 281 0707 00 CAP FXD CER DI 15000PF 10 200V 80009 281 0707 00 A1C15 285 1341 01 CAP FXD MTLZD 0 1UF 20 100VDC 84411 X674L 1 20 100 A1C16 290 1311 00 CAP FXD AL 10UF 20 50V 5 X 11MM 5000 HRS RDL T A 80009 290 1311 00 A1C17 285 1341 01 CAP FXD MTLZD 0 1UF 20 100VDC 84411 X674L 1 20 100 A1C18 281 0775 01 CAP FXD CER M...

Page 165: ...ER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A1C60 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A1C61 281 0768 00 CAP FXD CER DI 470PF 20 100V TUBULAR MI 04222 SA101A471KAA A1C65 285 1301 01 CAP FXD MTLZD 0 47UF 10 50V TAPE AMMO PACK 37942 185 0 47 K 50 AB B A1C66 290 1311 00 CAP FXD AL 10UF 20 50V 5 X 11MM 5000 HRS RDL T A 80009 290 1311 00...

Page 166: ...09 131 5337 00 A1J4 131 3392 00 CONN HDR PCB MALE STR 1 X 10 0 1 CTR 0 230 MLG X 0 120 TAIL 30 GLD BD RETENTION 80009 131 3392 00 A1J6 119 1946 00 FLTR RFI 1A 250V 400HZ W PC TERM S4307 FN326 1 02 K D T A1L1 108 1412 00 COIL RF FXD 4 7 UH 20 Q 25 SRF 50 MHZ DCR 0 017 OHM I MAX 3 7 A RDL LEAD 54583 TSL08074R7M3RO A1L2 108 1412 00 COIL RF FXD 4 7 UH 20 Q 25 SRF 50 MHZ DCR 0 017 OHM I MAX 3 7 A RDL L...

Page 167: ... 2W TC TO 91637 CCF50 2 G4993FT A1R27 322 3300 02 RES FXD FILM 13K OHM 0 5 0 2W TC T2 57668 CRB20 DYE 13K0 A1R28 322 3344 00 RES FXD FILM 37 4K OHM 1 0 2W TC T0 80009 322 3344 00 A1R29 315 0470 03 RES FXD CMPSN 47 OHM 5 0 25W 80009 315 0470 03 A1R30 315 0103 03 RES FXD CMPSN 10K OHM 5 0 25W 80009 315 0103 03 A1R31 322 3385 00 RES FXD MET FILM 100K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB...

Page 168: ... 3385 00 RES FXD MET FILM 100K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 100K A1R66 322 3452 00 RES FXD FILM 499K OHM 1 0 2W TC TO 91637 CCF50 2 G4993FT A1R67 322 3001 00 RES FXD MET FILM 10 OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3001 00 A1R68 322 3121 00 RES FXD MET FILM 178 OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3121 00 A1R69 322 3289 07 RES FXD FILM 10K OH...

Page 169: ... 120 1945 00 XFMR RF PRI 8UH 2 7 ON OFF VERT MT PC MT 80009 120 1945 00 A1T3 120 1944 00 XFMR RF 80009 120 1944 00 A1TP1 214 4085 00 TERM TEST PT 0 070 ID 0 220 H 0 063 DIA PCB 0 015 X 0 032 BRS W RED NYLON COLLAR 26364 104 01 02 A1TP2 214 4085 00 TERM TEST PT 0 070 ID 0 220 H 0 063 DIA PCB 0 015 X 0 032 BRS W RED NYLON COLLAR 26364 104 01 02 A1U1 152 0900 00 MOD HV 7 5KVAC IN 15KVDC OUT POTTED MO...

Page 170: ...7 CM45210 A2R428 311 2540 00 RES VAR PNL CP 20K OHM 20 0 5W LINEAR W GROUNDING LUG 0 5 IN DIA 12697 311 2540 00 ATTACHED PARTS 214 4725 00 SPRING COMPRESSION SPRING 0 026 302 STAINLESS STEEL 0 313 0 0A0 8X345 214 4725 00 366 1701 01 KNOB GY 0 127 ID X 0 392 OD X 0 4 H 80009 366 1701 01 END ATTACHED PARTS A2R444 311 2540 00 RES VAR PNL CP 20K OHM 20 0 5W LINEAR W GROUNDING LUG 0 5 IN DIA 12697 311 ...

Page 171: ... X 0 100 AXIAL 04222 SA105E104MAA A3C8 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A3C10 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A3C11 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A3C12 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A3C13 2...

Page 172: ...178 00 CAP VAR PLSTC 1 3 5PF 500V 80009 281 0178 00 A3C56 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A3C57 281 0775 01 CAP FXD CER MCL 0 1UF 20 50V Z5U 0 170 X 0 100 AXIAL 04222 SA105E104MAA A3C58 281 0773 00 CAP FXD CER MLC 0 01UF 10 100V SAF 0 100 X 0 170 AX IAL MI 80009 281 0773 00 A3C59 281 0823 00 CAP FXD CER DI 470PF 10 50V 04222 SA101A471KAA A3C60 28...

Page 173: ...50MA 4NS 2PF 1N4152 DO 35 T R 80009 152 0141 02 A3CR5 152 0141 02 DIO SIG ULTRA FAST 40V 150MA 4NS 2PF 1N4152 DO 35 T R 80009 152 0141 02 A3CR6 152 0141 02 DIO SIG ULTRA FAST 40V 150MA 4NS 2PF 1N4152 DO 35 T R 80009 152 0141 02 A3CR7 152 0141 02 DIO SIG ULTRA FAST 40V 150MA 4NS 2PF 1N4152 DO 35 T R 80009 152 0141 02 A3CR8 152 0141 02 DIO SIG ULTRA FAST 40V 150MA 4NS 2PF 1N4152 DO 35 T R 80009 152 ...

Page 174: ...0009 131 4752 00 A3J4 175 9797 00 CA ASSY SP FLAT FLEX FLX 10 27 AWG 2 5 L 1X10 BOX X STR SLDR TAB CONN NON PLZ 00779 487729 1 A3J5 131 2919 01 CONN HDR PCB MALE STR 1 X 4 0 1 CTR 0 235 MLG X 0 112 TAIL 30 GLD 0 035 DIA PCB 80009 131 2919 01 A3J6 131 2919 01 CONN HDR PCB MALE STR 1 X 4 0 1 CTR 0 235 MLG X 0 112 TAIL 30 GLD 0 035 DIA PCB 80009 131 2919 01 A3J9 131 0391 00 CONN RF JACK 80009 131 039...

Page 175: ... CTR JUMPER 0 2 H LOW PF BLK 80009 131 3957 00 A3P300 131 3957 00 BUS CNDCT SHUNT 1 X 2 0 1 CTR JUMPER 0 2 H LOW PF BLK 80009 131 3957 00 A3Q1 151 0190 00 XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMPL 2N3904 TO 92 EBC 80009 151 0190 00 A3Q2 151 0188 00 XSTR SIG BIPOLAR PNP 40V 200MA 250MHZ AMPL 2N3906 TO 92 EBC 80009 151 0188 00 A3Q3 151 0476 00 XSTR PWR BIPOLAR NPN 100V 3 0A 3 0MHZ AMPL TIP31C TO 22...

Page 176: ... 100MHZ AMPL 2N5551 TO 92 EBC T A 56289 CT7916 A3Q30 151 0190 00 XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMPL 2N3904 TO 92 EBC 80009 151 0190 00 A3Q31 151 0190 00 XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMPL 2N3904 TO 92 EBC 80009 151 0190 00 A3Q32 151 0188 00 XSTR SIG BIPOLAR PNP 40V 200MA 250MHZ AMPL 2N3906 TO 92 EBC 80009 151 0188 00 A3Q100 151 0188 00 XSTR SIG BIPOLAR PNP 40V 200MA 250MHZ AMPL 2N3...

Page 177: ...FXE 20K0 A3R29 311 2236 00 RES VAR TRMR CERMET 20K OHM 20 0 5W 0 197 SQ SIDE ADJUST T R TK1450 GF06UT 20K A3R30 322 3306 00 RES FXD MET FILM 15K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 15K0 A3R31 322 3260 00 RES FXD FILM 4 99K OHM 1 0 2W TC T0 57668 CRB20 FXE 4K99 A3R32 322 3318 00 RES FXD MET FILM 20K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 20K0 A3R33 322 3318 00...

Page 178: ... 322 3289 00 RES FXD MET FILM 10K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3289 00 A3R64 322 3421 00 RES FXD FILM 237K OHM 1 0 2W TC T0 91637 CCF50 2F23702F A3R65 322 3239 00 RES FXD FILM 3 01K OHM 1 0 2W TC T0 57668 CRB20 FXE 3K01 A3R66 322 3346 00 RES FXD MET FILM 39 2K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3346 00 A3R67 322 3222 00 RES FXD MET FILM 2K OHM 1 0 2W TC 100 PP...

Page 179: ...K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3258 00 A3R102 322 3258 00 RES FXD MET FILM 4 75K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3258 00 A3R103 322 3289 00 RES FXD MET FILM 10K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3289 00 A3R104 322 3165 00 RES FXD FILM 511 OHM 1 0 2W TC T0 57668 CRB20 FXE 511E A3R105 322 3318 00 RES FXD MET FILM 20K OHM 1 0 2W TC 100 PPM AX ...

Page 180: ...HM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3258 00 A3R143 322 3318 00 RES FXD MET FILM 20K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 20K0 A3R144 322 3377 00 RES FXD MET FILM 82 5K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 91637 CCF50 2F82501F A3R145 322 3024 00 RES FXD FILM 17 4 OHM 1 0 2W TC T0 57668 CRB20FXE1K62 A3R146 322 3044 00 RES FXD MET FILM 28 OHM 1 0 2W TC 100 PPM AX...

Page 181: ...2 3289 00 A3R181 322 3085 00 RES FXD MET FILM 75 OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 75E0 A3R182 322 3097 00 RES FXD MET FILM 100 OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 100E A3R183 322 3097 00 RES FXD MET FILM 100 OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 100E A3R184 322 3289 00 RES FXD MET FILM 10K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 8000...

Page 182: ...0 RES FXD MET FILM 10K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3289 00 A3R219 322 3306 00 RES FXD MET FILM 15K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 15K0 A3R220 322 3165 00 RES FXD FILM 511 OHM 1 0 2W TC T0 57668 CRB20 FXE 511E A3R221 322 3165 00 RES FXD FILM 511 OHM 1 0 2W TC T0 57668 CRB20 FXE 511E A3R222 322 3306 00 RES FXD MET FILM 15K OHM 1 0 2W TC 100 PPM AX IAL...

Page 183: ...C T0 91637 CCF50 2F17801F A3R307 322 3222 00 RES FXD MET FILM 2K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 2K00 A3R308 322 3164 00 RES FXD FILM 499 OHM 1 0 2W TC T0 57668 CRB20 FXE 499E A3R309 322 3222 00 RES FXD MET FILM 2K OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 57668 CRB20 FXE 2K00 A3T1 120 1907 00 XFMR RF BALUN R 1 1 FREQ RNG 20M 600MHZ INSR LOSS 10DB PKG 7 2MM SQ 6 8MM HI 8000...

Page 184: ...P16 3 80009 156 4199 00 A3U33 156 1149 00 IC LIN BIFET OP AMP LF351N DIP08 3 27014 LF351N GLEA134 A3VR1 152 0667 00 DIO ZENER 3V 2 0 4W DO 7 OR 35 TR 80009 152 0667 00 A3VR2 152 0667 00 DIO ZENER 3V 2 0 4W DO 7 OR 35 TR 80009 152 0667 00 A3VR3 152 0227 00 DIO ZENER 6 2V 5 0 4W 1N753A FMLY DO 35 OR 7 TR 80009 152 0227 00 A3W1 131 0566 00 BUS CNDCT DUM RES 0 094 OD X 0 225 L 80009 131 0566 00 A3W2 1...

Page 185: ...0 01UF 10 100V SAF 0 100 X 0 170 AX IAL MI 80009 281 0773 00 A4C690 290 0747 00 CAP FXD ELCTLT 100UF 50 20 25WVDC 24165 516D107M025LM7B A4C697 290 1311 00 CAP FXD ALUM 10UF 20 50V 5 X 11MM 5000 HOURS RDL T A 80009 290 1311 00 A4C782 290 1311 00 CAP FXD ALUM 10UF 20 50V 5 X 11MM 5000 HOURS RDL T A 80009 290 1311 00 A4CR481 152 0141 02 DIO SIG ULTRA FAST 40V 150MA 4NS 2PF 1N4152 DO 35 T R 80009 152 ...

Page 186: ... 50W 01121 EB1025 A4U583 156 1799 00 IC LIN BIPOLAR SW RGLTR CONT PWM SGL ENDED OC OUT NE5561N DIP08 3 80009 156 1799 00 A5 671 0042 03 CIRCUIT BD ASSY 70MHZ TUNER 80009 671 0042 03 ATTACHED PARTS 337 0607 00 PLATE ELEC SHLD CIRCUIT BOARD 80009 337 0607 00 QUANTITY 2 END ATTACHED PARTS A5C100 281 0697 00 CAP FXD CER DI 5000PF 100 0 100V 80009 281 0697 00 A5C102 281 0697 00 CAP FXD CER DI 5000PF 10...

Page 187: ...0009 317 0511 00 A5R279 317 0104 00 RES FXD CMPSN 100K OHM 5 0 125W 80009 317 0104 00 A5R281 317 0300 00 RES FXD CMPSN 30 OHM 5 0 125W 80009 317 0300 00 A5R291 322 3012 00 RES FXD FILM 13 OHM 1 0 2W TC T0 57668 CRB20FXE301E A5R292 322 3130 00 RES FXD MET FILM 221 OHM 1 0 2W TC 100 PPM AX IAL T R SM BODY 80009 322 3130 00 A5R293 322 3012 00 RES FXD FILM 13 OHM 1 0 2W TC T0 57668 CRB20FXE301E A5R297...

Page 188: ...0 00 SW SLIDE DPDT 3A 125VRM 80009 260 1780 00 MOUNTING PARTS 210 0201 00 TERM LUG 0 12 ID LOCKING BRZ TIN PL 86928 A373 157 2 210 0586 00 NUT PL ASSEM WA 4 40 X 0 25 STL CD PL 78189 211 041800 00 QUANTITY 2 END MOUNTING PARTS V1 154 0995 00 CRT FINISHED D14 375GH 995 SAFETY CONTROLLED 80009 154 0995 00 STANDARD ONLY V1 154 0995 16 CRT FINISHED D14 375WA 995 SAFETY CONTROLLED 80009 154 0995 16 OPT...

Page 189: ...Replaceable Electrical Parts 8 30 1705A Spectrum Monitor ...

Page 190: ...Diagrams Circuit Board Illustrations ...

Page 191: ......

Page 192: ...number in numerical sequence the components are listed by component number Example Chassis mounted components have no Assembly No prefix See end of Replaceable Electrical Parts List Assembly Number Component Number A23 A2 R1234 Subassembly Number if used Schematic Circuit Number Grid Coordinates The schematic diagram and circuit board component location illustration have grids A lookup table with ...

Page 193: ......

Page 194: ...Z AXIS AMPLIFIER 4X MULT V H FOCUS INTENS HIGH VOLTAGE POWER SUPPLY CONTROL LINE SIGNAL LINE KEY SCHEMATIC DIAGRAM NUMBER n 1705A Spectrum Monitor FRONT PANEL KNOB 7 40 VDC 15 VDC 5 VDC 15 VDC Z AXIS CONTROL CENTER FREQUENCY SWEEP SPEED SHAPERS 18V REAR PANEL VIDEO RESOLUTION INPUT SPAN DIV FRONT PANEL 130 5 MHz MICRO PROCESSOR 70 MHz INPUT IF AMP 8 dB ADC EPROM LOG DETECTOR NOTCH FILTER 130 5 MHz...

Page 195: ... R58 3 F2 E5 R59 3 B3 E6 R60 3 D3 E5 R61 3 C4 E6 R62 3 D3 F6 R63 3 D3 E6 R64 3 D4 E6 R65 3 F2 E2 R66 3 G3 F3 R67 3 G4 F4 R68 3 G4 F4 R69 3 F4 F4 R70 3 F3 F4 R71 3 F3 F4 R72 3 G4 F4 R73 3 F2 F4 R74 3 F2 F4 R75 3 F2 E5 R76 3 G3 F3 R77 4 D5 F2 R78 3 D5 F3 R79 3 E5 F3 R80 3 F3 F4 R81 3 G2 F5 R82 3 F3 F5 R83 3 E3 F5 R84 3 E3 F5 R85 3 D4 F6 R86 3 D3 F6 R87 3 E3 F6 R88 3 E4 F6 R89 3 C5 F2 R90 3 D5 F3 R91...

Page 196: ...Static Sensitive Devices See Maintenance Section A3 Main Board A5 70 MHz Tuner Board See parts list for earier values and serial number ranges ...

Page 197: ...Loc Diag Loc 1705A A5 C100 C4 C102 D4 C109 D1 C180 C2 A1 C181 B3 A1 C185 B3 B1 C192 C2 C1 C194 B2 C1 C196 B2 D1 C198 A2 C199 B2 D1 C279 D3 A2 C281 D3 A2 C282 C3 A2 C283 B3 A2 C284 C3 B2 C285 D3 A2 C286 D3 A2 C290 E2 B2 C292 E2 C2 C295 D2 C1 C298 D1 D1 C299 D1 D1 C389 F2 B2 C395 D2 C2 CR280 D3 A2 E100 C4 E101 C4 E102 D4 E103 D4 J400 A2 J890 F2 Comp No Bd Loc Diag Loc Comp No Bd Loc Diag Loc L193 C2...

Page 198: ...11 9 6 10 12 U283B CA3102 C181 560PF R184 510 R183 7 50K R281 30 R182 1 82K C180 560PF R181 3 92K C281 100PF C282 470PF 4T L280 45NH 1T L284 R279 100K CR280 C286 68PF C285 68PF A5 70 MHZ TUNER RAMP C279 001UF C102 5000PF E102 E103 CONT C185 470PF C284 470PF C100 5000PF SHIELD CAN E100 E101 C283 470PF 5 H2 LBAND R205 8 25K R216 8 25K Q21 CR31 R215 20 0K 11 8V 11 8V R214 4 75K Q20 3 H3 C80 1UF R237 ...

Page 199: ...H1 P6 F1 P10 E4 Q9 B3 I4 Q10 B4 I4 Q11 F2 J1 Q12 D2 J1 Q13 E2 J1 Q24 H4 M5 Q25 G4 M6 R136 G1 H2 R137 H1 H3 R138 A4 H5 R141 G1 I3 R145 G1 I3 R146 G1 I3 R147 B5 I3 R148 B5 I4 R149 A3 I4 R150 A4 I4 R153 F2 I1 R154 F2 I2 R155 B4 I4 R156 B3 I4 R157 B4 I4 R163 E2 J1 R164 E2 J1 R165 F2 I2 R166 F2 I2 R167 B4 I5 R169 E2 J1 R170 F2 J2 R171 B4 J4 R172 D4 J4 R173 E2 J1 R174 E2 J1 R175 C4 J4 R181 D2 J1 R182 E3...

Page 200: ...R182 100 0 R174 2 10K C61 33UF C36 33UF 11 8V TEST SELECTABLE RANGE 2 21K 3 32K R163 2 21K C43 470PF R165 301 0 R166 17 4 R154 301 0 R170 806 0 C51 001UF 4 C2 R208 14 7K R218 10 0K C88 200PF LOG 11 8V R219 15 0K Q25 Q24 11 8V R203 243 0 R202 243 0 C74 1UF 11 8V 20dBm MAX TEST ONLY 1 2 3 4 J10 P10 300 KHz RESOLUTION FILTER LOG DETECTOR R172 100 0 L7 210UH C48 1UF C53 1UF L3 210UH NOTCH R156 10 0K 1...

Page 201: ...88 E4 F6 R89 C5 F2 R90 D5 F3 R91 C5 F3 R92 F2 F4 R93 F2 F4 R94 E1 F4 R95 D1 F5 R96 C3 F5 R97 C1 F6 R98 C2 F6 R102 C5 G3 R103 C5 G3 R104 H3 G3 R105 H3 G3 R106 G3 G3 R107 G1 G4 R108 G2 G4 R109 D2 G5 R110 D3 G5 R112 C3 G5 R113 C2 G5 R117 H3 G3 R118 H3 G3 R119 H1 G3 R120 H1 G4 R121 G2 G4 R122 E2 G4 R123 E2 G5 R124 E2 G5 R125 E2 G5 R126 D1 G6 R127 C2 G6 R128 C1 G6 R129 C2 G6 R131 H3 H3 R132 H1 H3 R142 ...

Page 202: ...5 E3 R112 4 75K W4 0 OHM 1 2 U23A 7406 C20 1UF FULL 5V 11 8V R110 10 0K FULL MARKER GENERATOR 6 0V 8V R70 1 00K R82 5K R80 10 0K R71 2 00K R92 2 00K 5 6 7 U16B TL074 R93 10 2K 11 8V 1 R106 237 0K R66 39 2K R55 5K R105 20 0K CR13 R302 18 7K R303 20 0K CR32 11 8V 1 D4 R118 8 25K Q7 R117 511 0 R131 200 0 C30 1UF VCO 70 40V CR19 70 MHz LINEARITY 3V 3 2 1 4 1 1 U16A TL074 VR2 CR4 C25 001UF 11 8V 11 8V ...

Page 203: ...185 F4 K6 R186 G4 K6 R188 C2 K5 R189 F4 K6 R190 G4 K6 R191 G4 K6 R192 F4 K6 R193 G4 K6 R194 C2 K5 R197 G2 L5 R198 F5 L6 R199 F4 L6 R200 F5 L6 R204 D2 L6 R209 D2 L6 R210 D1 M6 R211 F3 L6 R212 F2 L6 R213 F3 L6 R220 F2 M6 R221 G2 M6 R223 F2 N5 R224 F2 M6 R225 F2 N6 R226 G2 N5 R227 G2 N5 R228 G2 N6 R229 F1 N6 R230 G1 N6 R308 E3 K5 R309 E3 K5 U15 C5 F2 U19 B5 G1 U21A B2 H6 U21B B2 H6 U21C B2 H6 U26A E4...

Page 204: ...IS Q22 R213 100 0 R211 100 0 11 8V 11 8V TO CRT 8 H2 RED GREEN HORIZ DEFL PLATES J8 J7 3W HORIZONTAL DEFLECTION AMPLIFIER R179 6 3K Q15 RAMP RAMP 3W R178 6 3K Q14 100V CONNECT FOR 10 DIV 5 5 H4 R180 10 0K W12 0 OHM R177 2 00K W11 0 OHM R309 2 00K R308 499 0 XAXIS W8 0 OHM 11 8V 5V 15V 11 8V 40V SUPPLY BOARD J23 J22 TO W698 PIN 1 TO W698 PIN 2 6 J21 TO S100 6 6 11 8V 11 8VF L19 64UH C102 1UF 15V PO...

Page 205: ...R27 H3 E3 R28 H4 D3 R29 H4 E3 R133 A3 H1 R245 C4 E1 R246 C5 E1 R300 C2 B6 U1 D3 A4 U2 D1 B3 U3 C3 B5 U4 D3 B6 U5 G5 C3 U6 G2 C3 U7A F2 B4 U7B E3 B4 U7C E2 B4 U7D F3 B4 U8 E1 C3 U9 F1 C4 U10 G3 D3 U11 C4 C6 U12A H4 D3 U12B H4 D3 W1 D1 C4 Y1 D1 B5 Schematic Diagram 5 Component Locator Chart Comp No The schematic diagram has an alphanumeric grid to assist in locating parts within that diagram Diag Lo...

Page 206: ...5B 30 16A 31 16B 32 17A 33 17B 34 J1 CONNECTS TO J303 FRONT BOARD 6 A2 PANEL J1 H1 NC 4 3 3 3 R133 68 1K FOCUS INTENS CFT SWP_SPEED ROTATE SCALE CFT LED_ON LED_300K LED_10K LED_70M INTENS S_SPD FOCUS D5 B3 A1 A3 R3 15 0K CFT 4 E3 3 C5 VREF 5 IN 2 DO 6 IN 3 VCC 8 CLK 7 CS 1 GND 4 U1 ADC0831 R1 7 32K R4 2K RO EN 5V 5V 3 C2 3 C3 4 5 6 U7B 74ALS00 9 10 8 U7C 74ALS00 FULL 10MHZ FULL 12 13 11 U7D 74ALS0...

Page 207: ...assist in locating parts within that diagram Diag Loc Bd Loc Comp No Assembly A2 and A4 Bd Loc Diag Loc 1705A A4 C491 D4 B1 C497 D4 C1 C580 C4 A1 C581 C4 A2 C583 B5 A1 C682 A5 A2 C683 B5 A2 C684 B5 B2 C690 E4 B2 C697 F4 C2 C782 A5 A3 CR481 C4 A1 CR485 D4 B1 CR494 D4 C1 CR594 D4 D1 DS698 F5 C2 J698 G4 D2 L591 D4 B1 L695 F4 C2 Q481 C4 A1 Q482 C5 A1 Q588 E5 B2 Q596 D4 D1 Q783 B5 B3 R485 C4 B1 R494 D4...

Page 208: ... SPAN DIV 100 KHz LED_100K 2 1 DS319A DS319 NOT INSTALLED 4 3 DS112B 6 5 DS112C 4 3 DS129B 4 3 DS319B 8 7 DS319D 4 3 DS144B 1 2 1 1 DS319F INTENS POSITION VERTICAL R528 20K INTENS V_POSN 11 8V 11 8V 11 8V 11 8V SCALE SWEEP SPEED R428 20K SCALE S_SPD 11 8V 11 8V 11 8V FOCUS R411 20K FOCUS 11 8V 11 8V 11 8V NC NC V_POSN 11 8V 11 8V 5V A2 FRONT PANEL BOARD GND FROM J23 4 10 TURN CENTER FREQUENCY R235...

Page 209: ...A2 L1 7 F3 F2 L2 7 F2 G1 L3 7 F2 G2 L4 7 C2 N1 Q1 8 E5 B3 Q2 8 E5 A3 Q3 8 D4 B4 Q4 8 D4 B4 Q5 8 C4 B4 Q6 8 B2 E1 Q7 7 D5 I4 Q8 7 E4 I4 Q9 7 D3 J1 Q10 8 A2 E2 Q11 7 G3 G3 R1 8 E3 A1 R2 8 E4 A2 R3 8 E4 A2 R4 8 E4 A3 R5 8 E5 A3 R7 8 B4 A4 R8 8 B4 A4 R11 8 F4 A2 R12 8 D3 C1 R13 7 F3 H4 R14 7 G3 H4 R20 8 C4 A4 R21 8 C5 A4 R22 8 D5 A4 R23 8 B4 A4 R24 8 D5 A4 R25 8 B4 A4 R26 8 E5 A3 R27 8 E5 A4 R28 8 E5 ...

Page 210: ...OHM W2 0 OHM 40VA 5D 5V C33 10UF C37 560UF NC J4 CONNECTS TO J4 A3 MAIN BOARD 100V 5V 15V 40V 4 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 J4 ZAXIS FOCUS J4 1 A4 A4 D5 8 8 8 5V Q11 ERROR R13 100 R14 10 0 5 1V VR3 H BOUNDARY ISOLATION Q9 R86 51 R90 2 4K CR20 Q9 R87 22 1 R82 4 99K R81 178 R101 49 9 NC NC R88 2 00K 5VC R79 49 9K C58 200PF C51 01UF C L 1 1 CX 6 RX 7 B 10 A 9 Q 12 Q 5 U4B 74HC221A C59 1...

Page 211: ...28 E5 A4 R29 D2 B1 R30 D2 A2 R31 D4 B3 R32 E5 B3 R33 C4 B4 R34 C4 B4 R35 D4 B3 R36 D4 B3 R37 C5 B4 R38 E2 B1 R39 E2 B1 R40 D2 B2 R41 D4 B3 R42 E3 C1 R43 E2 B3 R44 D2 B3 R45 F2 C4 R46 E3 C1 R47 D2 C3 R48 C2 C4 R49 F2 C4 R50 F2 E1 R51 F3 E1 R52 F2 E1 R53 F2 E1 R54 F2 E1 R55 D2 D4 R56 F3 E1 R57 B2 E1 R58 D2 E4 R59 B1 E2 R60 C1 E3 R61 D1 E4 R63 A2 E2 R64 C2 E2 R65 B1 E3 R66 B1 E3 R103 A2 E2 T1 B2 C4 U...

Page 212: ...WHT BLUE WHT GRAY BRN RED WHT RED WHT BRN WHT BLK RED WHT GRN 1st ANODE FOCUS 14 3 2 CATHODE 4 1 g3 12 g2 g1 k f f H4 H2 1 2 3 4 5 6 7 GREEN RED BRN BLUE HORIZONTAL DEFLECTION J3 1 2 3 4 5 6 7 4 WHT BLK BRN 1 2 3 4 1 2 3 4 5 6 7 f g1 k g3 g2 g4 g5 1 2 3 4 J1 J2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 SKT1 R11 2 5M C7 330PF J11 1W 1 2W R46 10 0 R1 1 5M R2 2 2M R36 2 00K R35 475 100V 100...

Page 213: ......

Page 214: ...Replaceable Mechanical Parts ...

Page 215: ......

Page 216: ...rt you have ordered has been replaced with a new or improved part your local Tektronix Inc Field Office or representative will contact you concerning any change in part number Change information if any is located at the rear of this manual Using the Replaceable Mechanical Parts List The tabular information in the Replaceable Mechanical Parts list is arranged for quick retrieval Understanding the s...

Page 217: ...ed to indicate relationship 1 2 3 4 5 Name Description Assembly and or Component Mounting parts for Assembly and or Component MOUNTING PARTS END MOUNTING PARTS Detail Part of Assembly and or Component Mounting parts for Detail Part MOUNTING PARTS END MOUNTING PARTS Parts of Detail Part Mounting parts for Parts of Detail Part MOUNTING PARTS END MOUNTING PARTS Mounting Parts always appear in the sam...

Page 218: ...43 FISCHER SPECIAL MFG CO 111 INDUSTRIAL RD COLD SPRING KY 41076 9749 75915 LITTELFUSE INC 800 E NORTHWEST HWY DES PLAINES IL 60016 3049 SUB TRACOR INC 78189 ILLINOIS TOOL WORKS INC ST CHARLES ROAD ELGIN IL 60120 SHAKEPROOF DIV 7X318 KASO PLASTICS INC 11013 A NE 39TH VANCOUVER WA 98662 80009 TEKTRONIX INC 14150 SW KARL BRAUN DR BEAVERTON OR 97077 0001 PO BOX 500 80126 PACIFIC ELECTRICORD CO 747 W ...

Page 219: ...00 00 2 SCREW MACHINE 2 56 X 0 750 PNH STL 83385 ORDER BY DESCR END MOUNTING PARTS 16 1 CIRCUIT BD ASSY MAIN SEE A3 REPL MOUNTING PARTS 17 211 0721 00 6 SCREW MACHINE 6 32 X 0 375 PNH STL 83486 ORDER BY DESCR END MOUNTING PARTS 18 196 3146 00 7 FLEX STRIP SINGLE JUMPER 1 0 L 15912 FSN LA 19 1 CIRCUIT BD ASSY GRATICULE LIGHT SEE A3A1 REPL 20 337 3428 00 1 SHIELD ELEC CIRCUIT BOARD PC 80009 337 3428...

Page 220: ...189 511 061800 00 END MOUNTING PARTS 47 1 CIRCUIT BD ASSY CRT SOCKET BD 80009 136 1167 00 SEE A10 REPL ATTACHED PARTS 179 2997 01 1 WIRE HARNESS DESCRETE CRT ASSY 5 24AGW 5 26 AGW 1 X 4 0 1 CTR 1 X 7 RCPT X 1 X 4 1 X 7 9M860 179 2997 01 344 0111 00 3 INSUL SPREADER DEFL LEADS POLYPROPYLENE TK1617 NA 343 0298 00 1 STRAP RETAINING 0 25 DIA CABLE 06915 HUC 4 174 3511 01 1 CA ASSY SP DISCRETE CPD 4 24...

Page 221: ... B041073 1 CA ASSY PWR 3 18 AWG 2 5M L BLACK 80126 C7120 25M BL STANDARD ONLY OPTIONAL ACCESSORIES 161 0215 00 1 CA ASSY PWR 3 0 75MU 2 5MM L GREY 80009 161 0215 00 EUROPEAN OPTION A1 ONLY 161 0066 10 1 CA ASSY PWR TK1373 24230 UNITED KINGDOM OPTION A2 ONLY 161 0066 11 1 CA ASSY PWR 3 1 0MM SQ 250V 10A 2 5 ME TER STR IEC320 RCPT AUSTRALIA SAF CONT 80009 161 0066 11 AUSTRALIAN OPTION A3 ONLY 161 00...

Page 222: ...10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 A5 32 33 34 35 A6 A4 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 57 A10 56 58 59 60 Test Equipment Depot 800 517 8431 99 Washington Street Melrose MA 02176 FAX 781 665 0780 TestEquipmentDepot com ...

Page 223: ......

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