TB 9-4931-488-35
8. Internal Reference Accuracy
a. Performance Check. Connect TIME BASE REF (rear panel) to frequency
counter. Adjust internal reference oscillator (located through hole on right-hand side of
front panel window) for a frequency counter indication of 5.000000 MHz.
NOTE
Check reference oscillator frequency again after 2 hours. The
reference will be between 4.9999995 and 5.0000005.
b. Adjustments. No further adjustments can be made.
9. Frequency Range, Accuracy, and Stability
a. Performance Check
(1) Connect frequency counter channel A to TI auxiliary output (rear panel).
(2) Frequency counter will indicate 1.070 MHz or greater.
(3) Turn FREQUENCY TUNE control fully ccw. Frequency counter will indicate
0.450 MHz or less.
(4) Set RANGE MHz switch to 64-32 and adjust FREQUENCY TUNE control for a
frequency MHz display of 50 MHz.
(5) Press COUNTER MODE EXPAND X100 pushbutton.
(6) Adjust frequency counter time base for 8 digits resolution. Difference between TI
display and frequency counter indications will be less than 110 Hz.
(7) Press COUNTER MODE EXPAND X100 released, X10 and COUNTER
MODE LOCK pushbuttons pressed.
(8) Allow 1 minute to acquire phase lock. Difference between frequency counter and
TI display indications will be less than 100 Hz.
(9) Release COUNTER MODE EXPAND X10 and LOCK pushbuttons.
(10) Observe frequency counter indication for 10 minutes. Frequency change will be
less than 500 Hz.
(11) Press COUNTER MODE LOCK ON pushbutton. Vary autotransformer from
123 to 105 V. Frequency counter indication will not vary more than 50 Hz.
(12) Adjust autotransformer for a 117 V output. Release COUNTER MODE LOCK
ON pushbutton.
(13) Release COUNTER MODE LOCK ON pushbutton and disconnect equipment
setup.
b. Adjustments. No adjustments can be made.
