Premier Mounts CDM-600 specifications Config RX RX-IF

CDM-600 Satellite Modem	Revision 7
Front Panel Operation	MN/CDM600.IOM

6.3.1.4CONFIG: RX

RX-IF DECODER DEMOD DATA DESCRAM EbNo

DATA=00064.000kbps SYMBOL=00037.333ksym

The sub-branches available are:

CONFIG: RX: RX-IF

ACQUISITION SWEEP RANGE = +/- 32 kHz

RX FREQ=070.0000 MHz SPECTRUM INVERT=OFF

Edit the Acquisition Sweep Range of the demodulator. The value of the digit is changed using the [↑] [↓] arrow keys. Press ENTER.

The value entered determines the amount of frequency uncertainty the demodulator will sweep over in order to find and lock to an incoming carrier. When operating at low bit rates, large values of sweep range (compared to the data rate) will cause excessively long acquisition times. For example: selecting ± 32 kHz with a data rate of 2.4 kbps, BPSK, will result in an average acquisition time of around 3 minutes.

Edit the Receive Frequency (RX FREQ) of the demodulator. Select the digit to be edited using the [←] [→] arrow keys. The value of the digit is changed using the [↑] [↓] arrow keys. Press ENTER. Note that the range is from 52 to 88 MHz, and 104 to 176 MHz. The resolution is 100Hz.

For units manufacured after February 2005, and which display CDM-600(E)on the opening menu, the range of IF frequencies has been extended to 50 - 90 MHz, and 100 - 180 MHz.

SPECTRUM INVERT should normally be in the OFF position. When in the ON position, the receive spectrum is inverted (which is the same as

IMPORTANT reversing the direction of phase rotation in the demodulator). Note that in BPSK mode, the demodulator will automatically synchronize to either the normal time-ordering of bits FEC codeword pairs, or the inverted ordering used by certain other manufacturers.

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