HP (Hewlett-Packard) HP 8568B TV Converter Box User Manual


 
12. Time Base Adjustment (SN 2848A to 3217A05567)
12. Time Base
Adjustment (SN
2848A
to
3217A05567)
Reference
Related Performance
Test
Description
Equipment
Procedure
Note
RF Section:
A27Al
Frequency Standard Regulator
A27A2
10 MHz Quartz Crystal Oscillator
Center Frequency Readout Accuracy Test
The frequency of the internal 10 MHz Frequency Standard is
compared to a known frequency standard and adjusted for minimum
frequency error. This procedure does not adjust the short-term
stability or long-term stability of the 10 MHz Quartz Crystal Oscillator,
which are determined by characteristics of the particular oscillator
and the environmental and warmup conditions to which it has been
recently exposed. The spectrum analyzer must be ON continuously
(not in STANDBY) for at least 72 hours immediately prior to oscillator
adjustment to allow both the temperature and frequency of the
oscillator to stabilize.
FREPUENCY STANDARD
14
Figure 3-54. Time Base Adjustment Setup
Frequency Standard
........................
HP
5061A/B
Frequency Counter
.........................
HP
5334A/B
Cables:
BNC cable, 122 cm (48 in) (2 required) . . . . . . . . HP
10503A
The spectrum analyzer must be ON continuously (not in STANDBY)
for at least 72 hours immediately prior to oscillator adjustment.
This allows both the temperature and frequency of the oscillator to
stabilize. Adjustment should not be attempted before the oscillator is
allowed to reach its specified aging rate. Failure to allow sufficient
stabilization time could result in oscillator misadjustment.
Adjustments 3-99