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SECTION I
GENERAL INFORMATION
1-1 INTRODUCTION
This manual provides the user of the Model XL-DC-600, XL-DC-601 or XL-DC-602 Time and
Frequency Receiver all of the information necessary to properly install, operate and utilize all of its
features.
The information in this manual includes normal installation procedures, as well as any maintenance and
adjustment data that may be required to facilitate field repairs.
The purpose of the Model XL-DC is to provide accurate time, frequency and position as derived from
Coarse Acquisition (C/A) Link 1 (L1) signals transmitted by the NAVSTAR Global Positioning System
(GPS) satellites. In addition, it provides high resolution measurements of external time and frequency
signals applied as inputs to the XL-DC versus the GPS reference. The XL-DC is usable on a
world-wide basis under any weather conditions.
The XL-DC is completely automatic in satellite acquisition and time and frequency synchronization.
When the unit is first installed (or if the unit is moved more than 100 km, or if the internal battery was
discharged), acquisition time is shortened if the operator enters a position accurate to better than
100 km (approximately one degree in latitude and longitude).
The XL-DC receiver will operate when the satellites are 10 degrees above the horizon and their signals
are not obstructed. Whenever entered position information is less accurate than 10 m, the XL-DC will
first have to accurately ascertain its antenna position by tracking four or more satellites and performing
a long term (24 hours) average of position fixes in order to maintain time and frequency accuracy and
stability within specification. From that point on, the XL-DC will require only one satellite (above 10
degrees) to maintain valid time and frequency. However, operation to specified stability requires four or
more satellites. When no satellites are in view, the XL-DC will continue to output its signals using either
the internal (or OPTIONAL external) disciplined oscillator.
1-2 LIMITED WARRANTY
Each new product manufactured by TrueTime is warranted for defects in material or workmanship for a
period of one year from date of shipment ("Limited Warranty"). Defects in material or workmanship
found within that period will be replaced or repaired, at TrueTime's option, without charge for material or
labor, provided the customer returns the equipment, freight prepaid, to the TrueTime factory under this
limited warranty. TrueTime will return the repaired equipment, freight prepaid, to the customer's facility.
This one year Limited Warranty does not apply to any software or to any product not manufactured by
TrueTime.
If on-site warranty repair or replacement is required, the customer will be charged the then current field
service rate for portal-to-portal travel time plus actual portal-to-portal travel charges. There is no
charge for on-site warranty repair labor.
Содержание 151-600
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