TB 9-6625-2211-24
14. Mode 4 Reply Accuracy
a. Performance Check
(1) Position controls as listed in 7 d above.
(2) Connect equipment as shown in figure 4, connection A.
(3) Set REPLIES MODULATION SEL switch to M4-3P.
(4) Adjust oscilloscope controls as necessary to view 3 pulses on Channel 1 display.
NOTE
In (5) below use the oscilloscope time base controls and the
timing markers on Channel 2 to make the timing
measurements.
(5) Measure the pulse spacing from leading edge of 1st pulse to leading edge of 2d
pulse and from leading edge of 2d pulse to leading edge of 3d pulse. In each case the
spacing will be 1.8 0.05 Ps.
(6) Measure the pulse amplitudes.
The pulse amplitudes as indicated on the
oscilloscope will be 5 0.5 V.
(7) While observing pulses on oscilloscope display set REPLIES SUB PULSE SEL
switch to M4-P2.
(8) Set REPLIES SUB PULSE POS SELECT switch to +.25. The 2d pulse will move.
(9) While observing pulses on oscilloscope set REPLIES SUB PULSE SEL switch
to M4-P3. The 3d pulse will move.
(10) Set REPLIES MODULATION SEL switch to M4-1P and REPLIES SUB
PULSE SEL switch to OFF. Pulses 1 and 2 will not be present on oscilloscope display.
(11) Using standard measurement technique, measure pulse risetime and falltime.
The rise time will be < 0.1 Ps and the fall time will be <0.2 Ps.
(12) Set switches as listed in (a) through (d) below:
(a) REPLIES REPLY WIDTH SELECT to 0.15.
(b) REPLIES SUB PULSE SEL to M4-P3.
(c) REPLIES SUB PULSE POS to VARY.
(d) REPLIES SIF REPLY CODE to 0020.
