Comtech EF Data SDM-100A - Manual (Page 93)

SDM-100A Satellite Modem Operation
Rev. 0 3–59
Reacquisition Programs the sweep re-acquisition mode time duration.
The time that is selected with this parameter is the time that the
modem will remain in a narrow sweep (
± 10%) after acquisition has
been accomplished. After this timer runs out, the modem will return
to the normal sweep.
On entry, the current programmed setting is displayed with a
flashing cursor on the first character. Use [
← ] and [ → ] to move the
flashing cursor. Use [ ↑ ] and [ ↓ ] to increment and decrement the
digit at the flashing cursor. Select the number of seconds for the
re-acquisition mode from 0 to 999 seconds. Press [ENTER] to
execute the change.
Carrier Mode Programs the modem for continuous wave mode. Four modes of
operation are available: Normal (OFF), Center, Offset, and Dual
modes. The Carrier mode is normally in the OFF position.
To change to Center, Offset, or Dual mode, enter the Carrier
Mode Menu and select the desired test mode.
Center Mode: A test mode that generates a carrier at the
current modulator frequency. This can be used to measure
the output frequency.
Offset Mode: A test mode that generates a single upper
side-band suppressed carrier signal. The upper side-band is
one-quarter the symbol rate from the carrier. This is used to
check the quadrature.
Dual Mode: A test mode that generates a dual side-band
suppressed carrier signal. Side-bands are one-half the
symbol rate from the carrier. This is used to check the
channel balance and carrier null.
On entry, the “CENTER” mode is displayed. To activate this test
mode, press [ENTER].
Press [ ↑ ] or [ ↓ ] to select the “DUAL” or
“OFFSET” mode. To return to the “CONFIGURATION” menu,
press [CLEAR].
Note: When [CLEAR] is pressed, the modem is configured to the
state it was in before “CW Mode” was invoked. The transmitter is
automatically turned off to prevent the possible swamping of
other channels. To turn the transmitter on, use the “IF Output”
function.