HEWLETT-PACKARD 204B Repair Manual

Model 204B Section V
Paragraphs 5-1 to 5-7
SECTION V
MAINTENANCE
5-1. INTR U I N.
5-2. This section provides maintenance and service 5232A/ S32A
FOR DIAL ACCURACY
information for the Model 204B Oscillator. Required
test equipment, replacement and adjustment proce-
dures, and a troubleshooting summary are included @ 2040
in the section. Also includedare performance checks I
which verify proper instrument operation, I
I
I 0330 C/D
5-3. REQUIRED TEST EQUIPMENT. I
5-4. Test equipment required for maintaining and -6OOn
checking performance of the Model 204B is listed in
table 5-1. Equipment having similar characteristics
can be substituted for the equipment listed.
5-5. PERFORMANCE CHECKS.
5-6. The performance checks verify that the Model
204B is operating normally and is accurately cali-
brated. These checks may be used after maintenance
or as part of incoming quality control inspection. In Figure 5-1. Test Setup for Dial Accuracy
the following checks be sure the test equipment used or Distortion Checks
has been recently calibrated.
5-7. DIAL ACCURACY CHECK.
c. Set frequency counter controls as follows:
a. Connect frequency counter and 600-ohm load to
oscillator output as shown in figure 5-1. Function. , 100 PERIODS AVERAGED
SENSITIVITY, ............ 3
b. Set Model 204B controls as follows: DISPLAY. maximum counterclockwise
RANGE., ............. XI d. Counter should read 200 i6 milliseconds.
FREQ.. ............... 5
AMPLITUDE. ......... MAX. e. Set FREQ. dial to 20, counter should read 50.0
VERNIER .......... centered i1.5 milliseconds.
Table 5-1. Required Test Equipment
Instrument Type Required Characteristics Us e Recommended Model
Oscilloscope Passband: dc to 600 kc Waveform checking @ Model 175A with
Sensitivity: 0.1 volts/cm plug-in Model 1753A
Input Impedance: 1 megohm
Distortion Analyzer Measure distortion to -40 db Distortion measurement @ Model 330B/C/D
1 kc
AC Voltmeter Frequency Range: 5 cps to AC voltage measurements @,I Model 400H
600 kc
Voltage Range: 1 mv to 5 volts
Accuracy: *l%
DC Voltmeter Voltage Range: Positive and DC voltage measurements @ Model 412A
negative voltages from 100 m
to 15 volts
Input impedance: at least 10
megohms
Clip-On Range: 5 to 11 milliamperes Charge current @ Model 428A
Milliammeter Accuracy: *3% measurements
Frequency Counter Counting Range: 5 cps to 600 kc Frequency measurements @ Model 5232A/5532A
Accuracy: 0.03%
01369-3 5-1