TB 9-6625-2021-24
NOTE
To determine time base drift limits for TI with other intervals:
multiply aging rate per day by the interval (days).
(4) Connect time/frequency workstation OUTPUT 1 MHz to frequency difference
meter REF INPUT.
(5) Connect TI 10 MHz OUTPUT (rear panel) to frequency difference meter SIG
INPUT.
NOTE
The time base is adjusted during each calibration in order to
correct for drift and improve reliability of the TI throughout the
interval. If TI is within the limits in step (3), then the following
FREQ ADJ adjustment will not be annotated as an out-of-
tolerance condition.
(6) Adjust FREQ ADJ (fig. 1) for a minimum indication on frequency difference
meter 1010 range. Record frequency difference meter indication.
Figure 2. TD-1225A(V)1/U (Hewlett-Packard, Model 5342A/H14), TD-1225A(V)2/U
(Hewlett-Packard, Model 5342A/H16), and Hewlett-Packard, Model 5343A - top view.
(7) Allow at least 24 hours for TI time base oscillator to stabilize. Frequency
difference meter indication will be within 5 parts in 1010 of indication recorded in step (6)
above. Record frequency difference meter indication.
(8) Adjust autotransformer output to 105 V ac. Allow 1 minute for oscillator to
recorded in step (7) above.
(9) Adjust autotransformer output to 125 V ac. Allow 1 minute for oscillator to
action recorded in step (7) above.
(10) Adjust autotransformer output to 115 V ac.
b. Adjustments. No further adjustments can be made.
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