Atec Tektronix-1502 - Manual (Page 49)

TM 9-4935-601-14-3&P
Adjustment Procedure
(e). Set the FEET/DIV to 5, set the TG 501 to 10 ns and check that when the first time mark is aligned
with the first graticule line, the eleventh time mark is 0 to 0.4 division to the left of the eleventh graticule line.
(f). Set the FEET/DIV to 2 and check that when the first time mark is aligned with the first graticule
line, the fifth time mark is 0 to 0.4 division to the left of the eleventh graticule line.
NOTE
The timing gets difficult to read because of noise at these sensitivities.
Try pressing the NOISE FILTER button to aid resolution.
(g). Set the FEET/DIV to 1 and check that when the first time mark is aligned with the first graticule
line, the third time mark is 0 to 0.4 division to the left of the eleventh graticule line.
(h). Release the NOISE FILTER button if it is pushed in.
(i). Set the FEET/DIV to 100, set the FEET/DIV multiplier to X.1, and set the TG 501 to 20 ns. Check
that when the first time mark is aligned with the first graticule line, the eleventh time mark is 0 to 0.4 division to
the left of the eleventh graticule line.
49. Adjust-C1332 (X.1 CAL) located on the MAIN board, so the eleventh time mark is 0.2 division to the left
of the eleventh graticule line when the first time mark is aligned with the first graticule line.
50. (a). Set the FEET/DIV to 200, set the TG 501 to 50 ns and check that when the first time mark is
aligned with the first graticule line, the ninth time mark is O to 0.4 division to the left of the eleventh graticule
line. Move the time marks by slight adjustment of the PG 502 Output (Volts).
(b). Set the FEET/DIV to 100 and set the TG 501 to .1
µ
s. Turn the DISTANCE dial fully
counterclockwise. Use the PG 502 Output (Volts) knob to set a time mark directly on a graticule line. Turn the
DISTANCE dial clockwise until the second time mark lines up with the same graticule line.
(c). Check-that the DISTANCE dial reads between 48.0 to 50.0 (480 to 500 X 0.1 ft). Alternately push
and release the ZERO REF CHECK button to make sure that the time marks are lined up on each other.
51. (a). Set the DISTANCE dial to 49.0 (490 X 0.1 ft).
(b). Adjust-R1315 (DISTANCE CAL) located on the MAIN board, for no movement of one time mark
while alternately pressing and releasing the ZERO REF CHECK button.
52. (a). Set the FEET/DIV multiplier to X1, set the TG 501 to 2,
µ
s and set CABLE DIELECTRIC to SOLID
POLY.
(b). Check-for 6.33 to 6.61 divisions between markers (turn the DISTANCE dial as necessary to see
two markers).
(c). Set CABLE DIELECTRIC to SOLID PTFE.
(d). Check-for 6.72 to 7.0 divisions between markers (turn the DISTANCE dial as necessary to see two
markers).
53. Set CABLE DIELECTRIC to OTHER and turn CABLE DIELECTRIC VAR fully clockwise.
54. (a). Check-for 9.7 to 10 divisions between markers (turn the DISTANCE dial as necessary to see two
markers).
(b). Turn CABLE DIELECTRIC VAR fully counterclockwise.
(c). Check-for <5.5 divisions between markers.
(d). Return the CABLE DIELECTRIC VAR to fully clockwise position.
55. Turn off the 1502, remove all test equipment and reinstall U1575. Install the shield over the
pulser/sampler circuitry (install 12 screws). Return the instrument to normal viewing position.
56. Turn on the 1502 and set mp/DIV to 200, set the FEET/DIV to 1, set CABLE DIELECTRIC to AIR (all
buttons out), and adjust the DISTANCE dial to 000.
X.1 Positioning
57. Connect the precision 50
Ω
terminator to the CABLE connector.
REV C FEB 1980
4-11