TB 9-6625-2309-24
8. Horizontal Scale Error
a. Performance Check
(1) Press DISPLAY FROM pushbutton to select ORIGIN.
NOTE
Softkeys have more than one function depending on mode of
operation.
(2) Perform (a) through (h) below:
(a) Press HELP pushbutton.
(b) Press MORE softkey.
(c) Press INSTRUMENT SETUP softkey.
(d) Press OTDR SETUP softkey.
(e) Press FIBER LEN/RES softkey.
(f) Adjust CURSOR A control to display NEW LENGTH & RESOLUTION
values to match LEN/RES values on TD-260C (850 nm) Horizontal Scale Data Sheet (first
cluster) (appendix A).
(g) Press ACCEPT CHANGES softkey.
(h) Press RETURN TO OTDR MODE softkey.
(3) Press DELAY pushbutton as necessary to set digital delay/pulse generator for
A=T+0.000010000000 (10 sec).
NOTE
At Index = 1.4990, 10 sec A = T+ delay corresponds to
approximately 1.0 km location where leading edge of FOCUS
generated pulse will occur on TI display; 20 sec to 2.0 km, etc.
NOTE
For optical module TD-285C, set digital delay/pulse generator
for A=T+0.000020000000 (20 sec).
(4) Perform steps (a) and (b) below:
(a) Press REAL TIME pushbutton and adjust FOCUS VAR ATTN 1 control
for minimum noise on trace prior to FOCUS GENERATED PULSE (fig. 4).
(b) Press FAST SCAN pushbutton and wait for LASER ON/AVG indication on
TI display to go off.
