126 E8257D/67D, E8663D PSG Signal Generators Service Guide
Troubleshooting
Troubleshooting the RF Path
Table 1-24 shows the amplitude ranges and the corresponding attenuator
switch control line voltages. Attenuation is switched in at +3 Vdc ±0.75
Vdc and switched out at 0 Vdc.
6. If the voltages are correct, replace the attenuator.
7. If the voltages are not correct, replace the A26 MID.
Table 1-24
Pin Numbers and Voltages
Amplitude
Levels
J13–5 40B dB
Atten. Step
J13–6 20 dB
Atten. Step
J13–7 40C dB
Atten. Step
J13–9 10 dB
Atten. Step
J13–10 5 dB
Atten. Step
+25 to +5.1 dBm 0 0 0 0 0
+5.0 to –4 99 dBm 0 0 0 0 +3
–5.0 to –14.99 dBm 0 0 0 +3 +3
–15.0 to –24.99 dBm 0 +3 0 0 +3
–25.0 to –34.99 dBm 0 +3 0 +3 +3
–35.0 to –44.99 dBm +3 0 0 0 +3
–45.0 to –54.99 dBm +3 0 0 +3 +3
–55.0 to –64.99 dBm +3 +3 0 0 +3
–65.0 to –74.99 dBm +3 +3 0 +3 +3
–75.0 to –84.99 dBm +3 0 +3 0 +3
–85.0 to –94.99 dBm +3 0 +3 +3 +3
–95.0 to –104.99 dBm +3 +3 +3 0 +3
>–105.0 dBm +3 +3 +3 +3 +3