Comtech EF Data SDM-9000 - Manual (Page 170)

Maintenance SDM-9000 Satellite Modem
6–12 Rev. 4
6.1.4.3 Demodulator PCB
Refer to Figure 6-7 for test point locations.
Test Points Signal Name
TP1 AGND.
Analog Ground.
TP2 I EYE.
I channel monitor. See Q EYE test point.
TP3 DGND.
Ground test point.
TP4 Q EYE.
Q channel monitor. The I and Q test points are digital representations of the
received filtered signal. To view these test points, use an oscilloscope in the
X-Y mode. The display will be the constellation shown in Figure 6-4.
TP5 DGND.
Ground test point.
TP6 DCLK.
Data Clock/3.
Figure 6-7. Demodulator PCB Test Points