Tektronix 3B2 TIME-BASE Instruction Manual page 17

SECTION 6
CALIBRATION
Introduction
This section contains a series of performance checks in
addition to calibration adjustments. If the Type 3B2 fails
a performance check, the trouble should be corrected before
continuing with this procedure.
PERFORMANCE CHECKS
Insert the Type 3B2 into the center plug-in compartment
of the Type 567 Readout Oscilloscope. Use a Type 3A2 in
the left-hand compartment and the Type 6R1] Digital Unit
in the right-hand compartment.
Connect a jumper cable from the 0.5-volt calibrator
output to the Channel 1 input, and adjust the controls for
a stable display (internally triggered) of several cycles of
the calibrator signal.
1. Triggering Controls
a. Turn the LEVEL control throughout its range and check
for stable triggering. Set to FREE RUN (detent position);
the sweep should free run.
b. Center the LEVEL control. The display should remain
stable in all positions of the COUPLING switch.
c. Set the SLOPE switch to be opposite position. The start
of the display should invert.
d. Set the SOURCE switch to LINE; the display should re-
main triggered. Set the SOURCE switch to EXT, and connect
another cable from the 0.5-volt calibrator output to the EXT
TRIG IN connector. The display should remain stable.
2. TIME/DIV Switch
a. Set the LEVEL control to FREE RUN (detent position).
Turn the TIME/DIV switch to each of its 18 positions, and
check for a display at each position.
3. DELAY TIME and Multiplier
a. Set the SWEEP DELAY switch to IN.
b. Turn the DELAY TIME switch to each position, and
check for a display on the crt.
c. Set the DELAY TIME switch to 10 ms, and turn the
multiplier dial. The display should move across the crt.
4. Clock, Decimal Point, and Unit of Measure
a. Set TIME/DIV to 1 mSEC, SWEEP DELAY to OUT, and
DIGITAL RESOLUTION to 10 pSEC.
b. Set the Type 6R1 MODE switch to TIME, and use the
manual Timing Start and Stop controls to measure 8 major
divisions on the graticule. The readout should be about
08.00MS
@1
c. Turn the TIME/DIV and DIGITAL RESOLUTION
switches to each of the following positions and note the
correct readout.
TIME/DIV DIGITAL Readout
1 SEC 10 mS 08.005
.5 SEC 10 mS 04.005
.2 SEC 10 mS 01.605
1 SEC TmS 0800.MS
50 mSEC TmS 0400.MS
20 mSEC T ms 0160.MS
10 mSEC 0.1 mS 080.0MS
5 mSEC 0.1 mS 040.0MS
2 mSEC 0.1 mS 016.0MS
1 mSEC 10 ps 08.00MS
5 mSEC 10 pS 04.00MS
.2 mSEC 10 pS 01.60MS
1 mSEC 1 ps 0800.5
50 uSEC 1 ps 0400. nS
20 pSEC 1S 0160.u5
10 pSEC 1 ps 0080. uS*
5 pSEC Tus 0040. 4S*
2 pSEC 1 ps 0016.uS*
*The Type 6R1 may not follow with the TIME/DIV switch set to
10, 5, or 2 pSEC.
This completes the performance checks.
CALIBRATION
The checks and adjustments described following should
be made at regular intervals. Although a check may show
that a circuit is within tolerance, it is good practice to reset
each adjustment to its optimum position. See Fig. 6-1 for the
location of the internal adjustments.
Equipment Required
1. Time-mark generator with markers at 1, 5, and 10
multiples from 1 psec to 1 sec, Tektronix Type 180A Time-
Mark Generator recommended.
2. Test oscilloscope with at least a 1-me bandwidth and
0.05-volt vertical sensitivity.
3. Two Tektronix 560-Series plug-in extensions, Tektronix
Part No. 013-034.
A. Insulated screwdriver, such as Jaco No. 125, Tektronix
Part No. 003-000.
Insert the two plug-in extensions into the center compart-
ment of the Type 567, and plug the Type 3B2 into the ex-
tensions. Turn the instrument on and allow at least 5 minutes