TB 9-6625-2089-24
(10) Set CHAL MODE SELECT switch to 4A and PRF SELECT switch to X1/2.
Press BIT (MOM) pushbutton, observe that three pulse reply is present.
b. Adjustments
(1) Adjust A8R5 (fig. 1) or 200 μs (R).
(2) Adjust A8R8 (fig. 1) for 0.5 μs (R).
(3) Adjust A8R10 (fig. 1) for 1.8 μs (R).
15. Mode 4 Disparity
a. Performance Check
(1) Connect equipment as shown in figure 4.
Figure 4. Mode 4 disparity - equipment setup.
(2) Position switches as listed in (a) through (c) below:
(a) CHAL WIDTH SELECT to 0.50.
(b) CHAL MODE SELECT to 4A.
(c) PRF SELECT to X1/2.
(3) Position and hold CHAL INHIBIT switch to DISPARITY (MOM). Observe
pulse in 66 μs position (26th pulse) of mode 4 challenger word. Observe that pulse in 66 μs
position (26th pulse) is inhibited and transfers from oscilloscope CH2 input to oscilloscope
CH1 input.
(4) Set CHAL INHIBIT switch to ISLS ON. Press and hold BIT (MOM)
pushbutton. Adjust oscilloscope to center last pulse on CH2 input on crt graticule.
Measure spacing between last pulse on oscilloscope CH2 input and pulse on oscilloscope
CH1 input. Pulse on oscilloscope CH1 input will be within 1 μs of last pulse on
oscilloscope CH2 leading edge, if not perform b below.
