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CXR Larus 80-100-400 Issue 2 July 2006 page
3-39
b. 1.544 MHz ±1.6 x 10
-9
(±2.5 x 10
-3
Hz)
if tracking DS1 inputs (Stratum 2)
c. 2.048 MHz ±1.6 x 10
-9
(±3.28 x 10
-3
Hz)
if tracking E1 inputs (TNC)
3.3714 Pull-in
Range:
a. 1.544 MHz ±1 x 10
-11
(±1.544 x 10
-5
Hz)
in GPS mode (Stratum 1/PRC)
b. 1.544 MHz ±2.5 x 10
-8
(±3.9 x 10
-2
Hz)
if tracking DS1 inputs (Stratum 2)
c. 2.048 MHz ±2.5 x 10
-8
(±0.05 Hz)
if tracking E1 inputs (TNC)
3.3715 Holdover
Drift:
±1 x 10
-10
per day over any ±5
°
C temperature range
3.3716 Traceability:
<1 x 10
-11
3.3717 Warmup Time:
If the 54593 has been unplugged for more than 20 minutes, it can take up to 5
hours before the GPS receiver has achieved Stratum 1/PRC accuracy. If the
54593 has been unplugged for less than 20 minutes, it can take up to 2 hours
before the GPS receiver has achieved Stratum 1/PRC accuracy in the Known
mode. During this time, the 54593 will be tracking an input signal with Stratum
2/TNC accuracy if an input signal is present.
NOTE:
The output driver cards (Models 54571 through 54577) will not deliver an output whose
frequency is within specification until the 54593 card has completed its warmup cycle
following plug-in or power turn-on.
3.3718 Acquisition
Times:
a. GPS
mode:
1. From power-up after more than 20 minutes off, 5 hours maximum.
2. From power-up after less than 20 minutes off, 2 hours maximum in
Known mode.
b. DS1 or E1 mode:
1. From power-up, after warmup time:
600 seconds (ACQUIRE 1 state).
2. From HOLD state returning to normal tracking:
1000 seconds (ACQUIRE 2 state).
