TB 9-6625-1967-24
(12) Adjust RET LOSS (dB) (SENSITIVITY (dB)) FINE control to 12 dB. TI will
indicate 8 divisions of display.
(13) Remove termination.
(14) Set RET LOSS (dB) (SENSITIVITY (dB)) switch and adjust FINE controls to
0dB and adjust 0-dB SET control fully ccw. Record amplitude of TI display.
(15) Adjust 0-dB SET control fully cw. Display amplitude will be at least four times
greater than amplitude recorded in (14) above.
b. Adjustments. No adjustments can be made.
9. Timing
a. Performance Check
(1) Set RET LOSS (dB) (SENSITIVITY (dB)) switch to 20 dB and FEET/DIV
switch to 50.
(2) Connect equipment as shown in figure 2.
s and
(3) Adjust pulse generator for -5 V output and pulse width of 100
external triggering.
(4) Set oscilloscope calibrator MODE for 1 S markers and TRIG to /100.
S marker
(5) Adjust pulse generator amplitude and pulse width for a stable 1
display on TI.
(6) Using ZERO REF SET control, move TI pulse off screen. Adjust oscilloscope
calibrator to align markers with display graticule lines. If oscilloscope calibrator does not
indicate 1 S 2 percent, perform b below.
b. Adjustments. Adjust R1216 (fig. 3) to align 1 time marker per graticule division.
10. Distance Dial
a. Performance Check
(1) Set FEET/DIV switch to 5.
(2) Adjust ZERO REF SET control cw until last time marker appears before fully
cw is reached and set its leading edge on the second graticule line from the left.
(3) Adjust DISTANCE dial to 050. If leading edge of second time marker does not
align with second graticule line within 1 digit of DISTANCE dial reading, perform
b below.
(4) Repeat technique of (3) above for DISTANCE dial settings of 100, 150, 200, and
250. Verify that each time marker is located on reference graticule line within 1 digit of
DISTANCE dial reading.
