TB 9-6625-2309-35
NOTE
Some TI/FOCUS combinations will not produce proper external
triggering of digital delay/pulse generator at a trigger threshold
of +0.05 V. Reduction of trigger threshold in this case to obtain
a good trigger is acceptable for attenuation scale non-linearity
measurements only.
(d) SLOPE (+/-) to +.
(e) TRIGGER TERM to 50 OHM.
(f) Press MENU OUTPUT pushbutton to cycle through steps (g) through (k)
below.
(g) OUTPUT to AB
(h) AB & -AB LOADS to 50 OHMS
(i) AB: VAR
(j)
AB: AMPLITUDE to +2.00 V
(k) AB: OFFSET to -1.60 V.
(l) Press MENU DELAY pushbutton to set A Delay to A=T+ 0.000050000000
(50 sec).
(m) Press MENU DELAY pushbutton to set B Delay to B=A+ 0.000010000000
(10 sec).
(10) Carefully remove optical fiber jumper cable connection from lightwave
multimeter OPTICAL INPUT (fig. 3) and connect to TI fiber connector.
(11) Press TI DISPLAY FROM pushbutton to select ORIGIN.
(12) Use technique of 8a(2) above to set TI NEW LEN/RES to 8.0 km/0.5m.
(13) Press PULSE WIDTH pushbutton to select LONG.
(14) Set FOCUS-SWCM SWITCHED ATTN switch to OUT.
(15) Press REAL TIME pushbutton.
(16) Adjust FOCUS-SWCM VAR ATTN 1 control until FOCUS generated pulse has
approximately same amplitude as dead zone pulse as displayed on TI (fig. 8).
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