Comtech EF Data CDM-625A - Page 57

CDM-625A Advanced Satellite Modem MN-CDM625A
Introduction Revision 4
1–15
Output impedance
950-1950 MHz band: 50
Ω
, 19 dB minimum return loss (21 dB typical)
1950-2250 MHz band: 17dB minimum
50-180 MHz band: 50Ω, or 75Ω 16 dB minimum return loss (18 dB typical)
Output connector
950-2250 MHz band: Type N female
50-180 MHz band: BNC female
Clocking options
Internal, ±0.06 ppm (SCT)
External, locking over a ±100 ppm range (TT)
Loop timing (Rx satellite clock) - supports asymmetric operation - Rx and Tx data rates need not be identical
External Clock
G.703 Clock Extension mode – internal ST clock can be slaved to an external T1 or E1 G.703 signal, and a G.703
timing signal re-constituted at the distant end of the link, regardless of the actual link data rate
External TX Carrier Off
By TTL 'low' signal or external contact closure - hardware function automatically over-rides processor
BUC Reference (10 MHz):
Phase Noise
On center conductor of L-Band output connector; 10.0 MHz
±
0.06 ppm (internal reference selected)
0.0 dBm, ± 3 dB; programmable ON/OFF
Source: either Internal Modem Reference or External Reference (10 MHz)
dB/Hz
-105 10 Hz
-125 100 Hz
-138 1 kHz
-148 10 kHz
-150 100 kHz
Frequency Offset
BUC Supply Voltage
•
Standard unit has no BUC supply.
• Optional BUC Supply:
o 24VDC, 4.17 Amps maximum, 100W
o 48VDC, 3.125 Amps maximum, 150W @ 50° C (180 watts @ 30° C)
o Supplied through Tx IF center conductor and selectable ON/OFF via M&C control.
BUC Current Monitor
Min/Max programmable current alarm thresholds.
Tx Carrier ON Delay
Selectable feature power on to allow internal ovenized reference to stabilize before turning on Tx carrier. Intelligent
algorithm minimizes delay time based on internal temperature at power-up.
BUC Monitoring
Power level, temperature, power class, PLL lock.
Uses ND Satcom/Global VSAT Forum specification for FSK control and monitoring.