TB 9-6625-2089-24
9. Timing Marker Accuracy
a. Performance Check
(1) Connect TIMING MKRS out to frequency counter input, using 93 Ω cable and 75 Ω
termination.
(2) Position controls as listed in paragraph 7 e above.
(3) Frequency counter will indicate 10.000 0.002 MHz.
(4) Disconnect cable and termination from frequency counter channel A. Connect
cable and termination to oscilloscope CH1 input.
(5) Connect SCOPE TRIG OUT to oscilloscope AUX TRIG IN, using 93 Ω cable.
(6) Adjust oscilloscope controls as necessary to display a series of three pulses of
different amplitudes.
(7) Measure time between leading edge of first and second pulses with greatest
amplitude. If the time is not 10 μs and the pulse amplitudes are not between 2.2 and 2.8
V, perform b (1) below.
(8) Repeat technique of (7) above for pulses with second greatest amplitude. If the
time is not 1.0 μs and the pulse amplitudes are not between 1.5 and 1.9 V, perform b (2) below.
(9) Repeat technique of (7) above for pulses with third greatest amplitude. If time is
not 0.1 μs and the pulse amplitudes are not between 0.8 and 1.2 V, perform b (3) below.
b. Adjustments
(1) Adjust A9R12 (fig. 1) for a pulse amplitude of 2.5 V as indicated on oscilloscope (R).
(2) Adjust A9R13 (fig. 1) for a pulse amplitude of 1.7 V as indicated on oscilloscope (R).
(3) Adjust A9R14 (fig. 1) for a pulse amplitude of 1.0 V as indicated on oscilloscope (R).
10. Output Trigger Accuracy
a. Performance Check
(1) Connect SCOPE TRIG OUT to oscilloscope CH1 input, using 93 Ω cable and 93
Ω termination. Connect AUX TRIG OUT to oscilloscope AUX TRIG IN, using 93 Ω cable.
(2) Set PRF SELECT RANGE switch to X1K and PRF SELECT MULT control to
1.0. Oscilloscope will display a pulse with an amplitude between 4.0 and 6.0 V and a width
of 1.0 to 5.0 μs.
(3) Set SCOPE TRIG/FREQ MEAS DELAY (μSEC) RANGE switch to X0.4 and
PRF SELECT MULT control to 10.0.
(4) Measure risetime and falltime using standard measurement techniques.
Risetime will be less than 0.1 μs and falltime will be less than 0.5 μs.
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