Comtech EF Data CDM-600/600L - Manual (Page 268)

CDM-600/600L Open Network Satellite Modem Revision 3
Appendix H MN/CDM600L.IOM
H–4
H.5 Tx Side Setup
Step Procedure
Front Panel Menu
Reference
13 Disconnect BUC. N/A
14 Determine the voltage required by the BUC and record for
reference N/A
15 Turn the BUC Power = ON and Verify the BUC Voltage is
correct. The voltage sent to the BUC is verified two ways per
the next step. BUC
16 The BUC voltage is reported under the Monitor Menu.
Alternatively, the BUC voltage can be measured at the center
conductor of the transmit IF connector. Use care to assure
that the volt meter probe does not short to the connector
outer conductor.
To avoid damage to the BUC, confirm voltage matches the
BUC voltage requirement. (Typical Voltage is +24 or +48
VDC
± 5%)
MONITOR
17 To protect the equipment, select the BUC Power = OFF. This
is necessary before connecting the L-Band coaxial cables to
the unit BUC
18 Set the TX Terminal LO (MHz) and MIX (+ or -).
The LO frequency is the BUC local oscillator frequency;
Mix = “-” if the BUC LO > Satellite Frequency
Mix = “+” if the BUC LO < Satellite Frequency
BUC: MORE
Consult BUC
manufacturer’s LO
specifications.
19 Set Tx Spectrum Invert ON if MIX is “-“. CONFIG:TX ÆTX-IF
20 Program the satellite frequency under the TX Terminal
Frequency menu CONFIG:TX ÆTX-IF
21 Set the TX Power Level to a safe (low) value CONFIG:TX ÆTX-IF
22 Turn TX carrier to Off. CONFIG:TX ÆTX-IF
23 Connect BUC. N/A
24 Turn BUC 10 MHz reference to ON. BUC
25 Turn BUC power supply ON. BUC
26 To automate warm up and delay carrier turn ON for a
programmed delay after prime power is applied see the BUC
carrier output delay menu. BUC: MORE
27 Record the nominal BUC current after the unit is warmed up
and functioning normally. MONITOR: BUC
28 Set the High alarm about 20% higher than nominal BUC
29 Set the Low alarm about 20% to 40% lower than nominal. BUC
IMPORTANT
At this point, the unit will start transmitting when the TX-IF output is tuned On
(under CONFIG: TX
Æ
TX-IF menu).