Comtech EF Data DST - Manual (Page 56)

Digital Satellite Terminal System Revision 1
Operation MN/DST.IOM
5–4
the satellite, it will be necessary to temporarily match the spectral inversion of modulator
and demodulator when performing IF loopback testing.
Note: The modem will only allow programming of terminal frequencies that are within
its valid L-Band frequency limits.
5.3 Applying Power To The BUC
CAUTION
1. Care should be exercised in cable installation. Install the cables using
the most direct route and secure with clamps and ties. Avoid all sharp
bends. Replacement of the cables can be the result.
2. If the ODU voltage is not correct, DO NOT connect the TX-IF Cable to
the modem or damage may result. Contact Comtech EF Data Customer
Service department.
3. Ensure TX and RX L-Band cables are not connected. After the modem is
checked out, then configure to operate with the ODU.
4. Initially, set LNB and BUC current wide enough to avoid false reports
during installation. Readjust the limit at a later time.
5. For FSK operation with an FSK capable BUC see the modem manual.
Complete steps 13 through 29 prior to continuing.
Note: Refer to Section 2, for proper installation of the IFL cables.
The conditions for the BUC to TX and the LNB to function are:
Proper TX L-Band power to the BUC from modem.
Sufficient and correct DC power at the BUC and LNB
10 MHz reference supplied to the BUC
10 MHz reference supplied to the LNB for EXT REF units
Note: Manufacturer recommends a 5-minute warm-up period at initial turn on for the
ODU to ensure proper performance. This can be accomplished by performing steps 15
through 18, prior to initiating the power start-up.