Atec Tektronix-1502 - Manual (Page 41)

TM 9-4935-601-14-3&P
Performance Check
11. Remove the 50
Ω
terminator and connect the probe adapter to the CABLE connector (SN B040616 and
up). Change the mp/DIV control to 500. The amplitude of the pulse must be 4 divisions ± 0.12 division. If not,
the Vertical Amplifier circuit or Sampling circuit should be checked.
12. Set the FEET/DIV control to 1 and adjust the ZERO REF SET control so the leading edge of the
incident pulse is set on the vertical centerline.
13. Change the MULTIPLIER control to X.1. The leading edge of the incident pulse must be within 1
division of the vertical centerline. (If not, check the X.1 Position calibration (R1132), the Sampler Comparator,
or the Pulser Comparator.)
14. Attach the precision 50
Ω
cable (Tektronix Part No. 012-0482-00) to the CABLE connector and change
the FEET/DIV control to 5. Adjust the ZERO REF SET control to locate the incident pulse on the graticule
reference line (as indicated by the arrow on the graticule line). The reflected pulse should be 6.3 divisions to
the right of the incident pulse ( 1 minor division).
15. Adjust the DISTANCE dial until the reflected pulse is located on the graticule reference line. The
DISTANCE dial should read 031.5 1 digit.
NOTE
When using the more sensitive ranges of the FEET/DIV control, the 0.3 foot
between the CABLE connector and the Sampler must be taken into
consideration or measurements will appear to be 0.3 feet too long.
Push the ZERO REF CHECK button; the incident pulse should return to the graticule reference line. If the
incident pulse does not return to the graticule reference line, adjust the ZERO REF SET control so that the
incident pulse is located on the graticule reference line. Release the ZERO, REF CHECK control and check
that the reflected pulse is located on the graticule reference line. Adjust the DISTANCE dial if necessary; it
must remain at 031.5 1 digit. (If the DISTANCE dial reading is incorrect or the ZERO REF CHECK control
does not work properly, check the Distance Offset, Fast Ramp, and Pulse Comparator circuitry.) Return the
DISTANCE dial to 000.
NOTE
To more accurately check the DISTANCE dial, a known length of Solid
Polyethylene (V
p
= 0.66) cable (1000 to 1600 feet) should be used.
16. Change the FEET/DIV control to 20, the MULTIPLIER control to X1, and the mp/DIV control to 200.
Adjust the ZERO REF SET control so that the reflected pulse is located exactly on the 8th graticule line from
the left-hand edge of the graticule.
17. Adjust the DISTANCE dial to locate the reflected pulse on each graticule line. The DISTANCE dial
should read as follows: (If not, check the Distance Offset, Fast Ramp circuitry, and Sweep Inverter.)
Graticule Line Distance Dial Reading
8 000
7 020 0.9
6 040 1.3
5 060 1.7
4 080 2.1
3 100 2.5
2 120 2.9
1 140 3.3
0 160 3.7
18. Return the DISTANCE dial to 000, change the MULTIPLIER control to X.1 and repeat the above step.
19. Push the SOLID PTFE button in, do not readjust the ZERO REF SET control and adjust the DISTANCE
dial so that the reflected pulse is located on the 0 graticule line. The DISTANCE dial should read between
164.1 and 171.9. Push in the OTHER button (VAR control must be fully cw) and locate the reflected pulse on
the 0 graticule line with the DISTANCE dial. The DISTANCE dial should read between 234.7 and 245.3. (If
not, check the Sweep Inverter circuit.) Return the DISTANCE dial - to 000 when this step is completed.
20. Change the FEET/DIV control to 1, the MULTI PLIER control to X1, disconnect the precision 50
Ω
cable from the CABLE connector, and connect the precision 50
Ω
terminator to the CABLE connector. Adjust
the ZERO REF SET control to locate the pulse on the graticule center. Adjust the POSITION control to center
the pulse on the graticule.
REV SEP 1983
4-3