Tektronix P6042 PROBE, Instruction Manual

Page: 37 / 72

Calibration—Type P6042
c. Connect the P6042 probe to the 10 Ω loop. Lock the
slider.
d. Connect the 1 X probe across the 10 Ω resistor. See Fig.
6-9.
e. Switch Triggering Mode to Trig, Source to Norm, Time/
cm to 50 ms, and display to Single Sweep. Set High Freq
3 dB Point to 500 kHz. While operating the Reset lever, turn
Triggering Stability counterclockwise until the Ready light
stays on. Push Upper and Lower Store buttons.
f. Reach inside the front-panel probe
holder and close the
probe-operated switch (simulating the probe inserted into the
holder). While holding the switch closed, push the DEGAUSS
lever (hold for the
duration of the sweep) and release.
g. Check the stored display for a four-centimeter (0.4 V)
damped waveform lasting approximately 200 milliseconds.
See Fig. 6-10.
h. Remove the probes from the 10 Ω loop, place the P6042
probe in the holder (lock the slider), and remove the 1 X
probe from the oscilloscope input. Push Upper and Lower
Screen Storage Off buttons and switch display to Norm.
9. Adjust CURRENT/DIV BALANCE Range
(R16 or R17)
a. Reconnect the P6042 OUTPUT, terminated in 50 Ω, to
the oscilloscope input. See Fig. 6-6.
b. Set Volts/cm to 50 mV, Time/cm to 50
µs,
and Trig­
gering Mode to Auto. Switch input coupling to Gnd,
posi­
tion the trace on the center graticule line, and return to DC.
c. With the CURRENT/DIV switch set to 1 A, degauss the
probe and center the trace with the OUTPUT DC LEVEL con­
trol.
d. Switch CURRENT/DIV to 1 mA and again degauss the
probe.
e. Adjust either R16 or R17 to position the trace near the
center graticule line. (Leave the remaining adjustment count­
erclockwise.)
f. Degauss the probe several times and check to see that
the trace returns to within one centimeter of the prevous
position.
g. Switch CURRENT/DIV to 10 mA and check range of
CURRENT/DIV BALANCE for >5 cm. Switch to 1 mA, degauss
probe, and return trace to center graticule line with CUR­
RENT/DIV BALANCE.
10. Adjust Gain (R107)
a. Set Time/cm to 1 ms, and Volts/cm to .2 volt.
b. Preset the square-wave generator control as follows:
Repetition Rate Range 1 kHz *
Multiplier 1
Symmetry Midrange
Mode Hi Amplitude
Power On
c. Remove the cable from the P6042 OUTPUT and con­
nect to the square-wave generator Hi Amplitude output,
using the GR-to-BNC adapter. See Fig. 6-11.
d. Adjust the square-wave generator Amplitude for 5
centimeters of deflection (1 volt).
e. Remove the GR-to-BNC adapter and connect the cable
to the P6042 OUTPUT. Connect the GR 50 Ω terminating
current loop to the square-wave generator output (producing
a 20 mA square wave through the current loop).
f. Set CURRENT/DIV to 5 mA and Volts/cm to 50 mV.
Degauss the probe and connect to the current loop. See Fig.
6-12.
g. Adjust R107 for 4 centimeters of deflection.
11. Check CURRENT/DIV Attenuation
a. With the test equipment set as in the previous step,
change CURRENT/DIV to 10 mA and check for 2 centimeters
of deflection, ±3%.
b. Remove the current loop from the square-wave genera­
tor and disconnect the cable from the P6042 OUTPUT.
c. Connect the test equipment as in Fig. 6-11.
d. Switch Volts/cm to 2 volts and adjust square-wave
generator Amplitude for 5 centimeters of deflection (10 volts).
e.
Connect the test equipment is in Fig. 6-12.
f. Change Volts/cm to 50 mV and CURRENT/DIV to 50
mA. Check for 4 centimeters of deflection, ±3%.
g. Switch CURRENT/DIV to .1 A and check for 2 centi­
meters of deflection, ±3.
h. Switch CURRENT/DIV to .2 A, ,5A and 1A positions
and check for deflection of 1, 0.4 and 0.2 centimeter,
respectively. (The 1 A position may be checked for 0.5
centimeter with the Volts/cm switch set to 20 mV.) This step
is not intended as an accurate check of the attenuator toler­
ance, but as
a check for obvious open-circuits conditions in
the switch.
6-9