TB 9-6625-2309-35
NOTE
When calibrating TD-285C optical module, adjust VAR ATTN
1 control for approximately -38 dBm at 1310 nm and 1550 nm.
(3) Set FOCUS-SWCM SWITCHED ATTN switch to IN.
(4) Adjust FOCUS-SWCM VAR ATTN 2 control for an optical power amplitude
indication on lightwave multimeter 6.0 dBm (-0.5 dB) lower than recorded in (2)(c) above.
NOTE
This will produce a nominal 3 dB power level difference when
displayed on TI. Take care not to disturb optical fiber jumper
cable when making measurements or disconnecting fiber
connectors. Excess optical fiber jumper cable length should be
coiled in 6 inch (approximate) diameter loops and taped
temporarily to bench top to avoid unnecessary movement of the
cable.
(5) Lock FOCUS-SWCM VAR ATTN 2 control using locking tab on control.
NOTE
Steps which follow test repeatability of switched attenuator.
Referenced attenuation data sheet values will be averaged by
OFTS calibration software.
(6) Set FOCUS-SWCM SWITCHED ATTN switch to OUT and record lightwave
multimeter indication in Power High Ref column on TD-260C (850 nm) Reference
Attenuation Data Sheet (appendix A).
(7) Set FOCUS-SWCM SWITCHED ATTN switch to IN and record lightwave
multimeter indication in Power Low Ref column on TD-260C (850 nm) Reference
Attenuation Data Sheet (appendix A).
(8) Repeat steps a(6) and (7) above recording lightwave multimeter indication for
each remaining column (three total) on TD-260C (850 nm) Reference Attenuation Data
Sheet.
(9) Set digital delay/pulse generator controls as indicated in (a) through (m) below:
(a) Press MENU TRIG pushbutton to cycle through steps (b) through (e) below.
(b) TRIG to EXT
(c) THRESHOLD to +0.50 V
17
