Model 201C Section V
SECTION V
MAINTENANCE
5-1. INTRODUCTION. 5-10. CALIBRATION ACCURACY CHECK.
5-2. This section provides maintenance and service a. Connect test setup as shown in Figure 5-1
information for the Model 201C Audio Oscillator. The
section includes recommended test equipment, a tube b. Check the period or frequency for each frequency
replacement table, performance checks, adjustments, repair setting shown in Table 5-3.
procedures and a troubleshooting table. The performance
checks will verify proper iiistrument operation.
hp ZOIC
5-3. TEST EQUIPMENT. AUDIO
OSCILLATOR
54. Test equipment recommended for use in maintaining
and checking performance of the Model 201C is listed in
Table 5-1. Equipment having similar characteristics can be
substituted for the equipment listed.
5-5. PERIODIC MAINTENANCE.
54. The tuning capacitor drive bearing should be
lubricated once or twice a year depending upon the amount
Figure 5-1. Calibration Accuracy Check
of use. One drop of light machine oil in each of the bearing
holes is adequate. The holes are located in the hearing
projections of the vertical casting behind the front panel.
Table 5-3. Calibration Accuracy Check
5-1. The inside of the instrument should be cleaned
occasionally to prevent accumulation of dust and dirt from
shorting plates of the main tuning capacitor.
x1 20 period: 49.5 to 50.5 ms
so period: 19.9 to 20.1 ins
200 period: 4.95 to 5.05 ms
XI0 20 period: 4.95 to 5.05 ins
so freq: 495 to 505 Mz
Clean tuning capacitor with extreme care. 200 freq: 1980 to 2020 Hr
DO NOT apply any force to it which XI00 20 freq: 1980 to 2020 Hr
could beud the plates and destroy SO freq: 4950 to 5050 Hr
calibration. Compressed air under a 200 frcq: 19800 to 20200 Hz
pressure not to exceed 60 psi is
recommended for cleaning.
5-11. FREQUENCY RESPONSE CHECK.
5-8. PERFORMANCE CHECKS. a. Connect test setup as shown in Figure 5-2,
including a 600 ohm load resistor across the
5-9. The Performance Checks are front panel procedures output terminals of the Model 201C.
designed to compare the Model 201C with its published
specifications. These checks may be incorporated in b. Set the Model 201C frequency to 1 kHz and
periodic maintenance, post repair, and incoming inspection. Attenuation Switch to 0 dB.
The Performance Checks should be conducted before any
attempt is made to adjust or calibrate the instrument. A c. Adjust the Model 201C amplitude vernier to
Performance Check Test Card is provided at the end of this obtain 0 dB reading on the voltmeter.
section for recording the performance of the instrument.
The card may be removed from the manual and used as a d. Set the Model 201C to each of the frequency
permanent record of the incoming inspection or of a settings in Table S4. At each setting the voltmeter
routine Performance Check. should read 0 dB i-1 dB.
5-1 |
ACEC
