General Information; Introduction; Ordering Information - Symmetricom ATS-6511A User Manual

1 General Information

1.1

Introduction

The ATS-6511 is a state-of-the-art signal distribution system providing GPS disciplined time and
frequency references when locked to an ATS-6501. It utilizes an internal Ovenized Crystal
Oscillator (OCXO) and low noise synthesizer (LNS) in conjunction with fiber optic inputs from
an ATS-6501 to provide outputs that are characterized by the short-term stability of the OCXO,
medium term stability of the ATS-6501 internal Rubidium reference and the long-term stability of
the GPS constellation and/or and external Cesium reference. This provides a scalable architecture
that allows users to fulfill a wide range of current and future requirements with a single unit. The
ATS-6511 is suitable for a variety of precise time and frequency applications. Additionally, the
ATS-6511B provides the user with the capability to enhance the frequency stability and holdover
performance of the unit by using an external cesium (Cs) clock as the reference. An internal
rubidium option is also available in the ATS-6511B-R.
In applications where reliability is a must the ATS-6511 is capable of operating from an AC (100
– 240VAC, 50-60 Hz) or DC Power -48 VDC (SELV type) (-18 to -60 VDC) source and comes
with two fully redundant power supplies. The unit is capable of operating from a single supply in
the event one of the two power supplies fails.
1.2

Ordering Information

ATS-6511A: Standard dual fiber input time and frequency distribution chassis. Dual AC input
supplies included. Requires an external fiber time and frequency reference and includes two 1
PPS/DC IRIG, one 10 MHz, and one AM IRIG output module.
ATS-6511B: Long term holdover capability dual fiber input time and frequency distribution
chassis. Dual AC input supplies included. Requires an external fiber time and frequency
reference and includes two 1 PPS/DC IRIG, one 10 MHz, and one AM IRIG output module. A
rear panel BNC connector is included for an external holdover reference, for instance a Cesium.
The R option is available to provide an internal Rubidium for holdover.
ATS-6511C: Improved Phase Noise and Allan Deviation performance for the 1, 5, 10Mhz
outputs. All other features equivalent to the ATS 6511B.
Option D (DC Power Input): Provides DC input -48 VDC (SELV type) (-18 to -60 VDC)
capability instead of AC for one of the supplies. The second power supply is still AC.
Option D2 (Dual DC Power Input): Provides dual DC input -48 VDC (SELV type) (-18 to -60
VDC) capability instead of AC.
Option F (Front Panel Memory Card): Provides access to the unit's non-volatile memory via the
front panel. This option allows users to perform a complete software upgrade in the field without
returning the unit to Symmetricom.
Option R (Internal Rubidium, ATS 6511B & C only): Provides internal Rubidium for improved
holdover performance when both fiber inputs are not available.
ATS-6511A/B/C Users Guide
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DOC 6511_Release K