Atec Fluke-910-910R - Manual

Technical Data
910/910R GPS
Controlled Frequency Standards
The 910 and 910R GPS-con-
trolled frequency standards
deliver a precision frequency
and pulse-per-second time
“reference which, with its many
connectivity options, can be
installed, monitored and man-
aged from virtually any location.
Both models receive their long-
term frequency stability from
the built-in cesium standards in
the GPS-satellite array, yet can
also provide a very high short-
term stability from the built-in
oven controlled crystal oscillator
(OCXO) or rubidium oscillator (Rb).
Both the 910 and 910R are
fully traceable and extremely
accurate frequency standards
and are ideally suited for use
in many applications, including
telecommunications, calibration
and automatic test systems.
Unique traceability feature
means no more re-calibrations
Off-air frequency standards
have existed for several years.
But until now, they all have had
the same internal architecture
(Figure 1). The unit is, in effect,
a “black box,” with an antenna
input and a frequency output.
The local oscillators con-
trol process (disciplining) is
hidden from the user. Typically,
users have used another fre-
quency reference (for example,
a rubidium standard), a timer/
counter and a PC for logging the
deviation between the “black
box” and the frequency reference.
The concept of traceability
requires an unbroken chain of
comparisons to international
standards, on a continuing basis,
where all comparisons produce
documented results with stated
uncertainty.
Now, for the first time, a docu-
menting frequency comparator
and a very stable secondary
standard are united within the
same instrument together with
the GPS receiver.
The received GPS signal is
measured continuously against
the local oscillator. Phase and
frequency deviation is stored
internally and can at any time
be transferred to any PC directly
from the 910/910R or, via the
optional Ethernet interface, from
or to almost anywhere. Then by
using the GPSView
TM
software
supplied with every model, a
printout of the traceability record
can be obtained. The unbroken
calibration history chain—day
by day—is maintained in the
non-volatile memory for several
years, with the current 24-hour
mean offset being displayed con-
tinuously on the front panels LCD
display.
Such unique traceability to
primary standards means that
the 910 and 910R never need
to be away for re-calibration.
Thanks to this design, the very
high stability built-in rubidium
or OCXO oscillator is continuously
calibrated to the primary freq-
uency standards in the US Naval
Observatory and ultimately to
UTC, in both operating modes,
disciplined or manual hold-over.
Two high-stability models to
meet your application, and
fit your budget
Fluke Calibration offers two
standard models in its controlled
frequency standards range; the
very-high stability 910R with its
built-in rubidium atomic clock
as the local oscillator, and the
affordable 910 with its high
stability local oven controlled
crystal oscillator.
Figure 1. A typical “black box GPS receiver” (antenna in - reference out). Internal oscillator
offset and adjustments are invisible to the user.
The cesium controlled frequency standard that uses
GPS technology and connectivity to provide primary
standard traceability from any location
GPS-
Receiver
Phase
comparator
Local
oscillator
(VCO)
Reference Out (10 MHz)