HP 5501B Operating And Service Manual page 114

⑤
A3U20 (Pin 7).RC Input Waveform to U20's Internal
Oscillator/Logic Circuitry (~50 kHz)
Oscilloscope Settings:
Vertical Input: 2 Volts/Division
Horizontal Input: 10 μsec/Division
⑦
A3U20 (Pins 14 and 11). E-REF Drive Output
Waveform (~25 kHz)
Oscilloscope Settings:
Vertical Input: 5 Volts/Division
Horizontal Input: 20 μsec/Division
8-54
+4 VOLTS
-≈
- 0 VOLTS
Waveform photographs
taken with all test
jumpers in the NRM (left-
most) position.
10:1 Probe Attenuation
not considered when
establishing vertical
channel input settings.
A3U20 (PIN 14)
0 VOLTS
-
A3U20 (PIN 11)
0 VOLTS
-
⑥
A3U20 (Pin 9). E-REF or Subtracting Sample and
Hold Difference Input Waveform
Oscilloscope Settings:
Vertical Input: 1 Volts/Division
Horizontal Input: 20 μsec/Division
⑧
A3U20 (Pins 12 and 13). ±15 Volt Heater Control
Drive Output Waveform (~25 kHz)
Oscilloscope Settings:
Vertical Input: 2 Volts/Division
Horizontal Input: 10 μsec/Division
HP5501B
Service
+2 VOLTS
-≈
- 0 VOLTS
A3U20 (PIN 12)
+15 VOLTS
-≈
A3U20 (PIN 13)
+15 VOLTS
-≈