Comtech EF Data CDM-550T, Manual

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Front Panel Operation CDM-550T Satellite Modem
6–14 Rev. 1.3
(CONFIG, TX) TSI (Transmit Spectral Invert)
Select either OFF or ON, using the LEFT/RIGHT arrow keys, then press
ENTER.
When in the ON position, and QPSK is selected, the transmit spectrum is
inverted (which is the same as reversing the direction of phase rotation in the
modulator). In BPSK, the time-order of bits out of the FEC encoder is reversed,
to make the modem compatible with certain other manufacturer’s modems.
6.2.3.2 (CONFIG) RX (Receive)
The sub-branches available are:
(CONFIG, RX) MOD (Modulation)
Select BPSK, QPSK, or Offset QPSK demodulation, using the LEFT/RIGHT
arrow keys, then press ENTER. (Note: if a TURBO FEC option is selected, the
demodulation type will be automatically fixed, and the user will be presented
with a warning screen.)
SELECT TRANSMIT SPECTRAL
INVERSION: OFF ON(ENTER)
RX: MOD FRQ DATA FEC ACQ
DESCRAM CLK BUF RSI EbNo
SELECT RX MODULATION:
BPSK QPSK OQPSK (ENTER)