Wavetek 188 Manual page 30

Table 6-7. VCG Circuit
Indication: Generator does пої respond correctly to dial апа VCG input.
Check
If Faulty, Check
1/2);
13.
Set controls to initial positions (геїег to paragraph 6.4).
Check for approximately +15V atE11.
Check for 0 +5 mV at U1 pin 13.
Check 01 pin 14 for approximately — 5V.
Check that as the dial is rotated from 4.0 to .004, the voltage
at U1 pin 14 varies from approximately - 5 to ОМ.
Ensure that U1 pin 5 remains at a constant ОМ +40 mV as the
dial is varied.
Check that, as the dial is rotated from .004 to 4.0, the voltage
at U1 pin 1 does not saturate near — 15V ог + 15V (typical range is
between — 10V and + 10V) and stops varing with the dial.
Check that as the dial is rotated from .004 to 4.0, U6 pin 8 varies from
approximately — 15V to — 10V.
Check that, as the dial is rotated from .004 to 4.0, the voltage at
U1 pin 7 does not saturate near + 15V or — 15V (typical range is between
-- 10V and — 10V) and stops varying with the dial.
Check that, as the dial is rotated from .004 to 4.0, U4 pin 13 varies from |
approximately + 15V to + 10V.
Check frequencies of x 1K, x 10K and 100K ranges.
Check frequency and linearity of х 1M range.
Check frequencies of x1, x 10 and x 100 ranges.
Check for normal operation.
a. E10, E11 and E12 wiring.
b. 4- 15V supply.
c. Dial potentiometer.
Wit
ШЕ
U1.
U1, U4, and U6 circuits.
Q6, U1, and U6 circuits.
U6, U1, and Q6 circuits.
U4 and U1 circuits.
U4 and U1 circuits.
a. Associated timing
capacitors or C36.
р. U5, CR6.
с. 09, О10.
а. Adjust R19.
b. C30, 31 and 32
(trimmed by С20).
a. C34.
b. C36 nominal value.
с Со 19, 20 апа 21.
886 and table 6-9.
а. 03.
b. U1 circuit.