Model 130B Sect.1V Page 13
4-12 CHECKING AND ADJUSTING THE B. VERT. AMPL. GAIN AND FREO. RESP. AD-
CALIBRATOR JUSTMENTS
1) Set HORIZ. SENSITIVITY to INT. SWEEP X1; To adjust the Vertical Amplifier gain and frequency
SWEEP TIME/CM to 1 MILLISECOND; SWEEP response refer to Figure 4-5 and proceed as
MODE to PRESET; SYNC. to INT.; andTRIG- follows:
GER LEVEL to ?0?.
1) Adjust Vertical and VERNIER balance as in-
NOTE dicated by Figure 2-2 and paragraph 4-13A.
If PRESET (SWEEP MODE) is maladjusted, you
2) Set HORIZ. SENSITIVITY to INT. SWEEP X1
may not obtain a trace. See paragraph 4-16.
------------ and set the SWEEP TIME/CM switch to 2 MILLI-
SECONDS, SWEEP MODE to PRESET and TRIG-
2) Set the VERT. SENSITIVITY switch to 50 GER LEVEL to ?0?.
MILLIVOLTS/CM. Place the VERNIER control
in CAL. 3) Place VERTICAL SENSITIVITY switch and its
VERNIER in CAL.
3) Connect the signal source to the vertical IN-
PUT terminals and set its rms output voltage, 4) Adjust R40 for exactly 6 centimeters deflection.
read on the vtvm, to 106 millivolts (300 mv/
2c) and its output frequency to 1000 cps. 5) Set VERT. SENSITIVITY to 50 MILLIVOLTS/
CM. Set SYNC to INT.
4) Adjust R40 (see Figure 4-5) to obtainexactly 6
centimeters deflection. 6) Set SWEEP TIME/CM switch to 5 MICRO-
SECONDS.
5) Set the VERT. SENSITIVITY switch to CAL.
7) Connect a 50 kc square wave to the Vertical
6) Adjust the R240 (see Figure 4-7) for exactly 6 INPUT and adjust the square-wave amplitude for
Centimeters deflection. 6 to 8 centimeters deflection.
8) Adjust C12 for best square wave. To give C12
4-13 ADJUSTING THE VERTICAL a range of adjustment sufficient to compensate for
AMPLIFIER .~ variations of tube characteristics. C13 may be
connected in parallel with C12 to increase the
The following adjustments are located in the vi-
maximum capacity to 1340 ppf.
cinity of the Vertical Amplifier or the VERT.
SENSITIVITY switch as shown in Figure 4-5.
A. VERNIER BALANCE ADJUSTMENT C. INPUT ATTENUATOR FREQUENCY
RESPONSE ADJUSTMENTS
To adjust VERNIER balance, allow the in-
strument to warm up 15 minutes and adjust Ver- To adjust frequency response of the input attenu-
tical balance as shown by Figure 2-2. Then refer ator refer to Figure 4-5 and proceed as follows:
to Figure 4-5 and proceed as follows:
1) Connect a 5 kc square wave to the Vertical
1) Short the INPUT terminals and set the INPUT INPUT.
switch to DC.
2) Set SWEEP TIME/CM to obtain 3 or 4 cycles
2) Set VERT. SENSITIVITY to 1 MILLIVOLT/CM, of the square wave.
and VERNIER to CAL.
3) Make the indicated adjustment for best square-
3) Center spot (or trace) with VERT. POS. control. wave presentation on the following ranges:
4) Turn VERNIER fully counterclockwise and re-
VOLT/CM ADJUST
turn spot to center with R20, the Bal. Adj.
10 c2
The trace should now be stationary as the VER- 1 c4
NIER is rotated. .1 c3 |