Comtech EF Data CDM-750 - Manual (Page 102)

CDM-750 Advanced High-Speed Trunking Modem Revision 2
Front Panel Operation MN-CDM750
5–24
• When you change the modulation, code rate, or other parameters, the modem
attempts to maintain the same Symbol Rate, provided it is still in range when one of the
other parameters is changed.
• When programming, the modulator will not accept a new data or symbol rate unless it is
in the range, and it will turn off the Tx Carrier. If a new rate is not accepted, change the
Modulator Code Rate or mode.
Press ENTER when done.
5.2.2.2.7 (CONFIG) Tx: Pilot
Tx: Pilot=Off Pilot Location=Peak
Goldcode=000000
( v)
Use the W X arrow keys to select Pilot or Goldcode, and then refer to the subsections that follow
to continue.
Pilot Location is read‐only and fixed at Average. When Pilots are enabled (i.e.,
Pilot=On), they will always be located at the “average” power point of any
constellation.
(CONFIG) Tx: Pilot
Æ Pilot
Use the ST arrow keys to select Pilot as On or Off. Note the following:
• Select Off to disable insertion of pilot symbols into the physical layer frame.
• Select On to enable insertion of pilot symbols into the physical layer frame.
Press ENTER when done.
(CONFIG) Tx: Pilot
Æ Goldcode
It is critical that the Tx Gold‐n Index Code value matches the Rx Gold‐n Index Code
value of the distant end modem.
The Gold‐n Index Code indicates the Physical Layer spreading sequence number.
First, use the W X arrow keys to select a digit to edit, and then use the ST arrow keys to change
that digit. Press ENTER when done. Note the following:
• The code can be set from 000000 to 262,141.
• The default setting is all 0s.