Anritsu 680XXC, Operation Manual, Page: 25 / 241

Warmup Time From Standby–When placing the 681XXC in op-
eration from stand-by, allow 30 minutes warmup to
assure stable operation.
From a Cold Start (0
°
C)–The signal generator re-
quires approximately 120 hours (5 days) of warm up
to achieve specified frequency stability with aging.
NOTE
Instruments disconnected from AC power
for more than 72 hours require 30 days to
return to specified aging.
Operating
Environment The 681XXC can be operated within the following
environmental limits.
q
Temperature. 0
°
C to 50
°
C.
q Humidity. 5 to 95% relative at 40
°
C.
q
Altitude. up to 4600 meters.
q Cooling. Internal cooling is provided by forced
airflow from the fan mounted on the rear
panel.
2-6 681XXC OM
PREPARATION
INSTALLATION FOR USE
Before installing the 681XXC in its operating environment,
ensure that all airflow passages at the sides and rear of the
instrument are clear. This is of particular importance when-
ever the unit is being rack-mounted.
Keep the cooling fan filter clean so that the ventilation holes
are not obstructed. A blocked fan filter can cause the instru-
ment to overheat and shut down.
CAUTION