Mocomtech CDM-570 - Manual (Page 183)

CDM-570/570L Satellite Modem with Optional IP Module Revision 4
Front Panel Operation MN/CDM570L.IOM
6–59
6.18.3 (UTIL) REF (Reference)
Select Adjust or Warm-up delay using the
◄ ► arrow keys, then press ENTER.
(UTIL, REF) ADJUST
If Adjust is selected, the following sub-menu is displayed:
Fine adjustment of the Internal 10 MHz reference oscillator is possible through
this menu. Use the
▲ ▼ arrow keys to edit the value. Note that in order to
facilitate adjustment, the value is updated as the digits are incremented – the user
does not need to press the ENTER key. The range of values is from –999 to
+999.
Note: The numbers displayed here do not correspond to an exact frequency
increment. A user should perform this fine adjustment while using an external
frequency counter, connected to either:
a) the internal 10 MHz reference, if the user has internal access to the
equipment, or
b) the Tx Output, set for CW, 0 dBm output level, and an exact center
frequency (1000 MHz, for example).
(UTIL, REF) WARM-UP DELAY
If Warm-up delay is selected, the following sub-menu is displayed:
Select Disable or Enable using the ◄ ► arrow keys, then press ENTER.
If the user selects Disable, the CDM-570/570L will power-up and go into normal
operational service without any delay. Because the CDM-570L uses a high-
stability oven-controlled 10 MHz reference oscillator (OCXO) there is a finite
time required for the oven to reach operating temperature. Consequently, there
will be a frequency error (as great as 2 x 10
-6 ) when the modem first powers up,
and it may take up to 2 minutes before the frequency has settled to its correct
Internal 10 MHz Freq Ref
Fine Adjust:+017(
◄ ►,▲ ▼)
Internal Freq Ref:Adjust
Warm-up delay (
◄ ►,ENTER)
Warm-up delay: Disable
Enable (
◄ ►,ENTER)