Util) Ref (Reference) - Comtech EF Data CDM-570L Installation And Operation Manual

CDM-570/570L Satellite Modem with Optional IP Module
Front Panel Operation
6.18.3

(UTIL) REF (Reference)

Internal Freq Ref:Adjust
Warm-up delay (◄ ►,ENTER)
Select Adjust or Warm-up delay using the
(UTIL, REF) ADJUST
If Adjust is selected, the following sub-menu is displayed:
Internal 10 MHz Freq Ref
Fine Adjust:+017(◄ ►,▲ ▼)
Fine adjustment of the Internal 10 MHz reference oscillator is possible through
this menu. Use the
▲ ▼
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:
Warm-up delay:
Enable
Select Disable or Enable using the
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
and it may take up to 2 minutes before the frequency has settled to its correct
◄ ► arrow keys, then press ENTER.
arrow keys to edit the value. Note that in order to
Disable
(◄ ►,ENTER)
◄ ► arrow keys, then press ENTER.
-6
) when the modem first powers up,
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Revision 4
MN/CDM570L.IOM