Comtech EF Data SDM-309B - Manual (Page 154)

SDM-309B Satellite Modem Maintenance
MN/U-SDM309B Rev. # 6-6–9
6.1.4.2 Demodulator (Figure 6-6)
TP10 VCXO Control Voltage
Approximately 0 to +2.5V sweep range.
TP23 Discriminator Voltage.
Nominally +2.5V with 6 dB noise at 128 Kbs.
TPG Ground test point
TP1 Q EYE pattern.
Level is 1V P-P at the center of the eye crossing. The DC offset is about +2.4V.
TP2 Q THRS - Q channel threshold voltage. +2.9V DC.
TP3 I THRS - I channel threshold voltage. +2.9V DC.
TP4 I EYE pattern.
Level is 1V P-P at the center of the eye crossing. The DC offset is about +2.4V.
TP5 Q CLK THRS +
Q channel + clock threshold. +2 to +3V DC.
TP6 Q CLK THRS -
Q channel - clock threshold. +2 to +3V DC.
TP7 I CLK THRS - I channel + clock threshold. +2 to +3V DC.
TP8 I CLK THRS +I channel - clock thr
eshold. +2 to +3V DC.
Figure 6-6