HP 4935A Operating And Service Manual page 7

Table of Contents
T i t l e
S e c t i o n
VI. REPLACEABLE
6-l. Introduction.. .................................................. .6-l
6-3. Replaceable Parts List.. ............................... ..6- 1
6-5. Ordering Information ................................... .6-l
VII. MANUAL CHANGES
7-1. Introduction .................................................... .7-l
7-3. Manual Changes.. .......................................... .7-l
7-6. Manual Change Instructions . ......................... 7-l
VIII. SERVICE
8-l. General Information .................................... ..8- 1
8-8. How Measurements are Made .................... .8-3
8-10. Level a n d Frequency.. ............................. .8-4
8-13. Noise.. ......................................................... 8-4
8-16. Noise-with-Tone ...................................... .8-4
8-19. Signal-to-Noise.. ....................................... .8-5
8-22. Impulse Noise .......................................... .8-5
8-26. Noise-to-Ground (Std & Opt. 001). ...... .8-6
8-29. Peak-to-Average Ratio: P/AR
8-32. Frequency Measurement.. ............................ .8-6
8-34. Level Measurement.. ..................................... .8-7
8-38. How to Compute Frequency and Level
Measurement ................................................. .8-8
8-39. Level Calculation Example.. ................... .8-8
8-42. Control Theory of Operation.. ..................... .8-11
8-44. Microprocessor t o Instrument.. ................... .8-11
System Latches.. ....................................... .8-H
8-45.
8-48. Instrument t o Microprocessor.. ................... .8-12
8-51. Operator to Microprocessor ........................ .8-12
Keyboard Interrupt.. ................................ .8-12
8-52.
Receiver Impedance Switches.. .............. .8-12
8-54.
8-57. Microprocessor t o Operator.. ...................... .8-13
8-58. Displays.. ................................................... .8-13
8-62. Monitor Amp ........................................... .8-13
8-64. Beep Generator ....................................... .8-13
8-66. Operator t o Instrument ................................ .8-13
8-68. Miscellaneous Circuitry.. .............................. .8-13
8-73. Receiver Theory of Operation.. ................... .8-15
8-76.
Termination .............................................. .a-16
vi
TABLE OF CONTENTS
P a g e
PARTS
S e c t i o n
8-80. Input Select/Notch Filter/
25 dB Amp.. ............................................. .8-17
Noise Filter Circuitry.. ............................ .8-17
8-85.
8-97. Level Detectors ....................................... .8-19
Impulse Noise Detectors.. ...................... .8-19
8-100.
Transmitter .................................................... .8-19
8-104. T e s t Signal Generation Method.. .......... .8-20
Circuit Description.. ................................ .8-21
8-126. Power Supply Theory.. .................................. .8-23
8-128. A C Line Supplies .................................... .8-23
8-131. Regulators.. .............................................. .8-24
8-139. Charger Board Theory of Operation.. ........ .8-25
8-141. Battery Charging.. ................................... .8-26
8-144. Power Source Selection.. ........................ .8-26
8-146. Relay Drive Circuitry.. ............................ .8-26
8-148. Inhibit Circuit ........................................... 8-26
8-153. Maintenance .................................................. .8-28
8-1.55. Periodic Maintenance.. ........................... .8-28
Failure Maintenance.. ............................. .8-28
8-159. Component Replacement ...................... .8-28
8-164. Soldering .................................................. .8-28
8-166 . Cleaning.. .................................................. .8-28
8-168. Disassembly .................................................... 8-29
Remove Case.. ......................................... .8-29
8-169.
Battery Charger Board Disassembly.. ........ .8-29
8-173. Switchboard/Front Panel Removal.. .......... .8-30
8-175. Transmitter Board Removal.. ...................... .8-30
8-177. Reassembly.. .................................................. .8-31
8-179. Power Supply Troubleshooting.. ................. .8-33
8-181. Minimum Core Troubleshooting.. .............. .8-34
8-183. Procedure .................................................. 8-35
8-186. Display Troubleshooting.. ...................... .8-36
8-189. Control Troubleshooting.............................. .8-36
Troubleshoot Keyscan/
Interrupt Circuitry.. ................................. .8-36
8-192. Control and Counting Section
Troubleshooting.. .......................................... .8-36
8-194. Transmitter Troubleshooting ...................... .8-37
Transmit Clock Generator.. ................... .8-37
8-196.
Transmitter Signature Analysis
Procedure.. ............................................... .8-37
Digital-to-Analog Conversion ............... .8-39
8-204. Filter and Signal Select Circuitry.. ........ .8-40
Output Amplifier.. ................................... .8-42
Transmit Monitor.. .................................. .8-43
8-212. Receiver Troubleshooting.. .......................... .8-43
Model 4935A
T i t l e
P a g e