Comtech EF Data SDM-2020, Installation And Operation Manual

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Operation SDM-2020 Satellite Demodulator
3–12 Rev. 3
Eb/N0 THRESH ALM Programs the Eb/No THRESH ALM ON or OFF.
When Off is selected, this function is disabled. When On is selected, the
ALARM LED and ALARM Rely are activated when the measured E
b
/N
0
falls below the programmed E
b
/N
0
THRESHOLD.
On entry, the current setting of the EB/NO threshold is displayed. Press[
↑
]
or [
↓
] to select the desired setting. Press [ENTER] to execute the change
SWEEP RANGE For L-Band only: Programs the overall travel of the sweep width range
during acquisition. The sweep width may be programmed from 0 to
1,000,000 Hz (± 500,000 Hz). When set at 100,000 Hz., the demodulator is
in normal acquisition mode (± 50,000 Hz).
For 70/140 MHz IF only: Range is 0 to 120,000 Hz.
The smaller the range, the faster the demodulator will lock to the receive
carrier center (provided the receive carrier center frequency is within the
RX IF frequency sweep range).
On entry, the current sweep frequency is displayed with a flashing cursor.
Press [
←
] or [
→
] to move the flashing cursor. Press [
↑
] or [
↓
] to increment
the digit at the flashing cursor. Press [ENTER] to execute the change.
REACQUISITION Programs the sweep reacquisition mode time duration. This is the time that
the demodulator will remain in a narrow sweep after loss of acquisition.
After this time runs out, the demodulator will return to the normal
acquisition sweep. The reacquisition time is from 0 to 999 seconds.
Upon entry, the current programmed setting is displayed with a flashing
cursor on the first character. Press [
↑
] or [
↓
] to increment or decrement the
digit at the flashing cursor. Select the number of seconds desired for the
reacquisition mode. Press [ENTER] to execute the change.
RF INPUT SELECT Programs the selected channel as 1, 2, 3, or 4.
Note: Only available with the 4-Channel card installed.
On entry, the current RF Input Channel is displayed. Press[
↑
] or [
↓
] to
select the desired setting. Press [ENTER] to execute the change