Description

EFData SDM-650B Satellite Equipment Modem

This EFData SDM-650B Satellite Equipment Modem is a high performance, full-duplex, Bi-Phase Shift Keying/Quadrature Phase
Shift Keying (BPSK/QPSK), digital modulator/demodulator (modem), for Frequency Division Multiple Access (FDMA) satellite communication systems. This product is used and non-functional purchasable for parts.

The modem contains:
• Built-in scrambler/descrambler
• Differential encoder/decoder
• Transmit and receive frequency synthesizers
• Multi-rate Forward Error Correction (FEC) convolutional encoder-sequential
decoder (Viterbi K=7 is optional)
The modem provides high performance with:
• Narrow occupied bandwidth
• Automatic signal acquisition
• High flexibility
• Extensive online monitoring circuits

EFData SDM-650B Satellite Equipment Modem Description

The modem is a complete, self-contained unit in a standard 19” rack-mountable enclosure
weighing approximately 25 lbs.
The modem is of modular construction (Figure 1-3).
The chassis assembly (with the front and rear panel) encloses several Printed Circuit Boards
(PCBs). The backplane PCB is mounted on the chassis assembly, and contains receptacles
for five plug-in PCBs.

We have two of these modems, neither are in working condition and can only be sold for parts. The boards slip out easily and if you have one of these old modems that you still need to operate then you should talk to us about buying this for the spare parts.