Model 130B Sect.IV Page 15
4-14 ADJUSTING HORIZONTAL AMPLIFIER Capacitor C115 may be connected in parallel with
To adjust the Horizontal Amplifier, refer to Fig- C114 to increase the maximum capacity to
ure 4-6 and proceed as follows: 1340 ppf, permitting a greater percentage of
vacuum tubes to be used.
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A. VERNIER BALANCE ADJUSTMENT
C. INPUTATTENUATORFREQUENCY
To adjust the VERNIER balance allow the in- RESPONSE ADJUSTMENTS
strument to warm up thoroughly and adjust Hori-
zontal balance as shown by Figure 2-3; then refer To adjust the frequency response at the input at-
to Figure 4-6 and: tenuator, refer to Figure 4-6 and proceed as
follows:
1) Short the INPUT terminals and set the INPUT 1) Set VERT. SENSITIVITY to 2 VOLTSICM.
switch to DC.
2) Set the HORIZ. SENSITIVITY to 1 MILLI- 2) Connect an 800 cps (approximately) sine wave
VOLT/CM and the VERNIER to CAL. to the Vertical INPUT of the oscilloscope and to
the Sync-In terminal of the 211A square wave
generator; adjust the sine wave for 10 centimeter
3) Center the spot with the HORIZ. POS. control. deflection.
4) Turn the VERNIER completely counterclock-
wise and return the spot to the center with R120, 3) Set HORIZ. SENSITIVITY to 10 VOLTS/CM
Bal. Adj. The spot will now be stationary as the (VERNIER in CAL.).
VERNIER is rotated. 4) Connect a 5 kc square wave to the Horizontal
INPUT and adjust its amplitude for 6 centimeter
B. AMPLIFIER GAIN AND FREQUENCY deflection.
RESPONSE ADJUSTMENTS
5) Make the following adjustments on the ranges
To adjust the gain and frequency response, refer indicated for the best square wave response, ad-
to Figure 4-6 and proceed as follows: justing the square-wave amplitude to 6 centi-
meters on each range.
1) Set HORIZ. SENSITIVITY switch to CAL. and
the VERNIER to CAL. VOLTS/CM ADJUST (see Fig. 4-6)
2) Adjust R144 for exactly 6 centimeters de- 10 c102
flection. 1 C104
.1 C103
3) Set VERT. SENSITIVITY to 2 VOLTS/CM.
4) Connect an 8 kc (approximately) sine wave to 4-15 PHASE SHIFT ADJUST
the Vertical INPUT of the oscilloscope and to the Phase shift between Vertical and Horizontal
SYNC. IN terminal of the 211A square wavegener- Amplifiers.
ator; adjust the sine wave for 10 cm deflection.
If the square wave response of the Vertical and
5) Set HORIZ. SENSITIVITY to 50 MILLI- Horizontal Amplifier was carefully set, the relative
VOLTS/CM. phase shift between the two amplifiers should not
exceed one degree at frequencies below 50 kc.
6) Connect a 50 kc square wave to the Horizontal
INPUT, and adjust the square wave amplitude for To check Phase Balance:
6 to 8 cm deflection. 1) Set VERT. and HORIZ. SENSITIVITY to 50
7) Adjust C114 for best square wave response. MILLIVOLTS/CM and VERNIER to CAL.
2) Apply a 50 kc sine-wave signal to the HORIZ.
NOTE INPUT and VERT. INPUT. Center pattern and
Some vacuum tubes require more capacity for adjust signal amplitude for 6 cm vertical and 6 cm
compensation than the maximum value of C114. horizontal deflection. |
ACEC
