Select Internal If Loop; Connect External Cables - Comtech EF Data CDM-Qx Installation And Operation Manual

CDM-Qx Satellite Modem
Installation
2.4

Select Internal IF Loop

Correct operation of the unit may be verified rapidly, without the need for externally
connected equipment, providing there are at least one modulator and one demodulator:
a) From the top-level menu, select
IMPORTANT
b) Then, go back to the top-level menu; select
'FRONT PANEL OPERATION' chapter).
The demod should synchronize, and the green RECEIVE TRAFFIC LED should
illuminate. If the unit does not pass this test, call the factory for assistance.
2.5

Connect External Cables

Having verified correct operation in IF loop, enter the desired configuration, and proceed
to connect all external cables. If difficulties occur, please call the factory for assistance.
Observe the following:
•
•
Note:
dBm for L-Band). Even though there is a single IF output connector and a single IF input
connector, all four slots are hooked up by way of internal power splitters and summers. If
two modulators are turned on, the total power out will be 3 dB higher (assuming both
modulators are set to the same power level). If four modulators are turned on, the total
power out will be 6 dB higher (assuming all modulators are set to the same power level).
This will require a modulator, with TX Output ON or ENABLED,
to be above a demodulator in the chassis.
If modulators and demodulators are to be used without grouping them as a
modem, a data interface cable is required to plug into each unit. If a modulator
and demodulator are grouped as a modem, the modulator must be located above
the demodulator and a single data interface cable is used simply by connecting it
to the demodulator.
If a modulator, demodulator, or grouped (modem) is defined as a back up unit, a
data interface cable is not required to the unit or units.
Each modulator has an output power level in the range -5 to -25 dBm (-5 to -45
CONFIG , then GROUP
TEST , then
2–4
Revision 6
MN/CDMQx.IOM
, then MODEM .
IF LOOP (refer to the