Wavetek 182A Instruction Manual page 28

Indication: Waveform symmetry problem.
1. Set controls to initial positions (refer to paragraph 6.4).
2. If symmetry problem appears on x 1, X 10, X 100 ranges only, problem
may be R90 adjustment or go to table 6-9.
3. Perform steps 5 through 12 of table 6-7, then return to this table.
4. Verify RUN signal at cathode CR6 is approximately + 3.5V.
5. Verify U6 pin 4 and U6 pin 15 vary from approximately -1 OV to -15V as
dial is rotated from 4.0 to .004.
6. Verify amplitude of SOR signal at cathode CR10 is approximately ± 2V.
7. Check U5, CR6.
Indication: Problem on bottom frequency ranges only.
Set controls to initial positions (refer to paragraph 6.4).
1.
2. Check for 0 Vdc at U11 pins 2 and 6.
3. Check for approximately 0 Vdc at U11 pin 12.
4. Check for 0 Vdc ± 5 mV at U 11 pin 10.
5. Select X 100 range; check U11 pin 10 for heavy oscillations.
6. Check that the signal at U11 pin 2 is amplified by approximately 6 at pin 12
(within saturation limits).
7. Check for the same signal at U11 pins 6 and 7 as at the emitter of 011.
8. Ensure that R93 and R94 are shorted in the x 100 range.
Check 400 Hz frequency (4.0 x 100).
9.
10. Check 40 Hz frequency (4.0 X 10).
11. Check 4 Hz frequency (4.0 x 1).
12. Check symmetry at 0.2 x 100; ensure triangle is linear.
6-6
6·8.
Table Symmetry
Check
6·9.
Table Capacitance Multiplier
Check
If Faulty, Check
Check for normal operation.
a. R49 adjustment.
b. R44, adjustment.
Go to table 6-10.
U1, U6, R52, R53.
a. 07 circuit.
b. U7 circuit.
c. + 5V supply.
If Faulty, Check
Check for normal operation
on X 1 K range.
SW2 - SW4.
U11 circuitry.
a. R90 adjustment.
b. U11 circuitry.
C46, U11.
U11 circuitry.
SW4, U11 circuitry.
SW4.
a. R86 adjustment.
b. R89, R95, C45.
R93, SW3.
R94.
a. R90 adjustment.
b. U11.
c. Leaky C30, C36, C45, C46,
CR6. U5. 09.