Maintenance
SDM-9000 Satellite Modem
6–8
Rev. 4
6.1.3 Demodulator
Use the following procedure and the test setup in Figure 6-1 to check out the
demodulator PCB. Refer to Chapter 5 for the demodulator specifications. Section 6.1.4.3
lists the demodulator test points and signal names. Figure 6-7 shows the test point
locations.
1. Set up the modem with an external IF loop, and level. Use a modulator that is
known to be properly operating, and ensure power levels, data rates, code rates,
etc., are compatible.
2. Allow the modem to lock up. When the green carrier detect LED is on and the
DEMUX lock fault has been cleared (where applicable), the modem should run
at the specified error rate. Run the TX power level (input amplitude) over the
full range and offset the TX frequency from the RX frequency by 30 kHz.
Ensure the modem still runs within the specified error rate.
3.
Set up the modem to check the constellation patterns with an oscilloscope that is
set in the X-Y mode. Typical constellation patterns with noise and without noise
are shown in Figure 6-4.
Содержание SDM-9000
Страница 1: ...Part Number MN SDM9000 IOM Revision 4 SDM 9000 Satellite Modem Installation and Operation Manual...
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Страница 5: ...8 Mbit s w IDR Figure 1 7 16QAM BER Performance Curves with Reed Solomon Filename T_ERRATA 3...
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Страница 27: ...SDM 9000 Satellite Modem Introduction Rev 4 1 5 Figure 1 3 SDM 9000 Block Diagram...
Страница 42: ...Introduction SDM 9000 Satellite Modem 1 20 Rev 4 This page is intentionally left blank...
Страница 64: ...Configuration SDM 9000 Satellite Modem 3 6 Rev 4 JP1 Figure 3 4 Interface PCB AS 3971...
Страница 65: ...SDM 9000 Satellite Modem Configuration Rev 4 3 7 Figure 3 5 Interface PCB AS 4477...
Страница 66: ...Configuration SDM 9000 Satellite Modem 3 8 Rev 4 JP1 JP6 JP7 Figure 3 6 Interface PCB AS 5618...
Страница 70: ...Configuration SDM 9000 Satellite Modem 3 12 Rev 4 Figure 3 7 Nyquist Filter Installation...
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Страница 124: ...SDM 9000 Satellite Modem Operation Rev 4 4 51 Figure 4 17 RF Loopback Figure 4 18 IF Loopback...
Страница 133: ...SDM 9000 Satellite Modem Theory of Operation Rev 4 5 5 Figure 5 3 Modulator RF Section Block Diagram...
Страница 150: ...Theory of Operation SDM 9000 Satellite Modem 5 22 Rev 4 Figure 5 6 Interface Block Diagram...
Страница 158: ...Theory of Operation SDM 9000 Satellite Modem 5 30 Rev 4 This page is intentionally left blank...
Страница 167: ...SDM 9000 Satellite Modem Maintenance Rev 4 6 9 WITH NOISE WITHOUT NOISE Figure 6 4 Typical Eye Constellations...
Страница 186: ...Maintenance SDM 9000 Satellite Modem 6 28 Rev 4 This page is intentionally left blank...
Страница 218: ...Options SDM 9000 Satellite Modem A 32 Rev 4 This page is intentionally left blank...
Страница 242: ...Remote Control Operation SDM 9000 Satellite Modem B 24 Rev 4 ref SE_ command...
Страница 254: ...Glossary SDM 9000 Satellite Modem g 6 Rev 4 This page is intentionally left blank...
Страница 256: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...