TB 9-6625-2217-24
8. Time Base Stability
a. Performance Check
(1) Connect time/frequency workstation 10 MHz output to frequency counter 10
MHz reference input connector and set frequency counter external reference on.
(2) Connect TI 10MHz STD. OUTPUT to frequency counter Channel A input.
(3) Verify frequency counter indicates between 9.999998000 and 10.00000200 MHz;
annotate calibration condition, and continue with procedure.
(4) Connect time/frequency workstation 1 MHz output to frequency difference meter
REF INPUT.
(5) Connect TI 10MHz STD. OUTPUT to frequency difference meter SIG INPUT.
NOTE
The following time base adjustment is performed during each
calibration to correct for aging (drift) and should only be
reported as an out-of-tolerance condition if the TI is not within
the limits in step (3) above.
(6) Adjust TI rear panel FREQ STD ADJUST FINE and COARSE for a minimum
indication on frequency difference meter 1010 range. Record frequency difference meter
indication.
(7) Allow at least 24 hours for oscillator stabilization. Frequency difference meter
indication will remain within 5 parts in 1010 of indication recorded in (6) above.
(8) Adjust autotransformer output to 105 V and allow 2 minutes for stabilization.
Frequency difference meter will indicate a drift of less than 5 parts in 1010.
(9) Adjust autotransformer output to 125 V and allow 2 minutes for stabilization.
Frequency difference meter will indicate a drift of less than 5 parts in 1010.
(10) Adjust autotransformer output to 115 V.
(11) Disconnect frequency difference meter from TI.
b. Adjustments. No further adjustments can be made.
9. Channel A Sensitivity
a. Performance Check
(1) Press TI INPUT A 50 /1M
(LED ON).
key to select 50
(2) Connect signal generator RF output to TI INPUT A.
(3) Set signal generator frequency to 160 MHz and amplitude to 1 mV. Slowly
increase signal generator amplitude until TI displays a stable indication at approximately
160 MHz. If signal generator amplitude exceeds 50 mV, perform b below.
(4) Repeat technique of step (3) above at 100 MHz and 10 MHz; if signal generator
amplitude exceeds 25 mV, perform b below.
