Wavetek 188 Manual page 34

Table 6-11. Sweep Circuit
Indication: Sweep or Ramp problems.
Check Corrective Procedure
1. Depress CONT (Sweep). a. U1.
Extend SWP/STOP. b. SW2.
Check E48 for +4V.
2. Depress SWP/STOP.
Check collector of Q3. 4V peak ramp.
If ramp amplitude is > 4V peak. U1, Q3.
If ramp amplitude is < 4V peak. Q1, Q2.
4. At SWP OUT check for period change of approximately 30 ms Q2, R22.
to 60s as the TIME control is rotated from full сем to full cw.
5. At SWP OUT check for ramp period drift. СА.
6. At E39 with STOP control full cw, ramp amplitude is 4V peak, with STOP R12, SW1, SW2.
control full ccw, ramp amplitude is OV.
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