Wavetek 182A, Инструкция по эксплуатации

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Table 6·2. Power Supplies and Generator Loop (Continued)
Indication:
Fuse blown, no power indication or no outputs.
Check
7. Check U7 pin 14 for +
5 Vdc and U7 pin 13 for - 5 Vdc.
If Faulty, Check
a. 04, 03, U2.
b. Excessive loading; use
board jumpers to isolate
cause.
8. Check U4 pin 13 for a dc shift from approximately + 10V to + 15V as the
Go to table 6-7.
frequency dial is rotated from 4.0 to .004. Check U6 pin 8 or a dc shift from
- 10V to - 15V as the frequency dial is rotated from 4.0 to .004.
9. Check anode CR6 for approximately + 3.5 Vdc.
Go to table 6-10.
10. If emitter 011 has a 4 kHz,
±
1.25V triangle, go to table 6-3.
11. Check for the same voltage at the gate of 09 as at the emitter of 011,
09 - 011 and associated
within saturation limits of the amplifier.
circuitry.
12. If the voltage at the emitter of 011 is � + 1.25V, check cathode CR10
. U7, 07 and associated
for approximately - 2.5V. If the voltage at the emitter of 011 is
:5
- 1.25V,
circuitry.
check cathode CR1 0 for approximately + 2.5V.
13. Check U5.
Table 6·3. Output Circuits
Indication: Function outputs missing or clipped when TTL sync output OK. Problem with triangle waveform.
Check
1. Set controls to initial positions (refer to paragraph 6.4).
2. Check emitter 011 for a 4 kHz,
±
1.25V triangle.
3. Select triangle function, rotate AMPLITUDE ccw, and check U13 pin 10
for a
±
1.25V triangle.
4. Rotate AMPLITUDE cw (MAX), DC OFFSET to OFF, and check 50n OUT
(HI) for a 20V p-p (open circuit) triangle.
5. Check for excessive discontinuities at the triangle peaks near the bottom
of a frequency range (other than x 1 to X 100).
6. Check for nonlinearities in the triangle slopes near the bottom of a fre­
quency range (other than x 1 to X 100).
7. Check for a waveform symmetry problem.
If Faulty, Check
Check for normal operation.
Go to table 6-2.
a. R114, R112 adjustments.
b. U13.
c. SW13.
a. Output amplifier circuit.
b. E15, E16 wiring.
a. U5.
b. SOR signal at cathode
CR10 not
±
2.5V.
a. Associated timing capaci­
tor or C36.
b. U5, CR6.
c. 09, 010.
Go to table 6-8.
6-3