Section V Model 1415A
Paragraphs 5-26 to 5-36
5-26. STEP ZERO LEVEL ADJUSTMENT. cable with solid polyethylene dielectric, such as RG58)
to exactly 100 cm length, including a connector at one
a. Set:
end.
DISTANCE/TIME MAGNIFIER * * * * * * * 50
b. Connect another 50-ohm cable (with connectors
MAGNIFIERDELAY - - * * - 0.00
on both ends) of at least 2 meters in length to the SIG-
NAL OUT connector. Connect STEP OUTPUT to
b. Adjust Step Zero Level R154 to eliminate DC
SIGNAL IN using the two 874-EL connectors.
shift of base line when 50-ohm load is connected to and
disconnected from the SIGNAL OUT connector.
c. Set:
5-27. SAMPLER DIODE BIAS ADJUSTMENT. REFL COEFFICIENT * * * - * * - * * 0.2
a. Set up 1415A functions as described in Para- CM LJNE/CM DISPLAY * * - * * - 2000
graph 5-17.
DISTANCE/TIME MAGNIFIER - * 200
b. Adjust 1st and 2nd Diode Bias, R410 and R412
d. Set the 50% point of the resulting open circuit
(located on bottom of sampler can), for display as
reflection to the 0. 0 cm point on the left side of the
shown in Paragraph 5-17.
graticule.
5-28. STEP CAL ADJUSTMENT.
a. Connect a 50-ohm loador short length of 50-ohm e. Adjust Time Scale Cal R252 so that open cir-
cuit reflection moves exactly 10 cm when calibrated
cable to SIGNAL OUT.
cable (step a) is connectedand disconnected from the
open end of cable connected toSIGNAL OUT connector.
b. Set:
CM LINE/CM DISPLAY * * * * * full cw f. Set:
DISTANCE/TIME MAGNIFIER * * - * * 1 CM LINE/CM DISPLAY * . * * - 200
MAGNIFIER. . . . - . . 20
REFLCOEFFICIENT * - * * * * * 0.1
g. Repeat step e, except that C330 is adjustd in-
REFL COEFFICIENT VERNIER * * CAL
stead of R252.
c. Adjust STEP CAL for 10 cm deflection.
5-35. METHOD TWO.
NOTE
Time scale adjustments given in Paragraphs a. Use any available 50-ohm transmission line or
cable of solid polyethylene dielectric type with a length
5-29 through 5-36 should be made in order.
of 50 cm to 200 cm as the calibratingcable. Measure
5 -29. DISTITIME CAL ADJUSTMENT. its length in cm exactly.
b. Perform steps b through g of Method one, above;
5-30. Set DIST/TIME CAL for llcm of sweep. the MAGNIFIER setting as required. Adjust
changing
R252 and C330 in steps eandg toprovide correct length
5-31. TIME SCALE CAL AND 20-NSEC TIME
readings.
SCALE CAL ADJUSTMENTS.
5-36. DOT DELAY ADJUSTMENTS.
5-32. COARSE 20-NSEC TIME SCALE CAL
ADJLBTMENT.
a. Remove the connection between STEP OUTPUT
and SIGNAL IN.
a. Turn off power and remove Model 1415A from
Qscilloscope. b. Set:
b. Set NSEC/CM to a position halfway between 20
and 50. HORIZ POSITION. - - * * to center trace
VERT POSITION - * * * . * to center trace
c. Connect LC Meter to 20 NSEC Time Scale Cal
MAGNIFIERDELAY * ' * * * * * 0.00
C330 at end nearest front panel.
d. Adjust C330 for 82 pf on the LC Meter. c. Adjust Min Dot Delay R272 to position intensi-
fied dot on left graticule line.
e. Disconnect LC Meter, replace Model 1415A in
Oscilloscope and turn on power. d. Set MAGNIFIER DELAY to 10.00.
5-33. The two time scale adjustments canbe made by
either of the following methods. e. AdjustMaxDotDelayR274 to position intensified
dot on left graticule line.
5-34. METHOD ONE.
f. Repeat steps b through e until intensified dot
lines up with both graticule lines without readjustment.
a. Cut a section of 50-ohm transmission line (use
5-4 01944- 4 |
ACEC
