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mined by the auto-adaptive algorithm, the 1 PPS
LOCK light will not illuminate.
5.5 Proper operation when tracking a 1pps signal is
indicated by all three front panel LEDs illuminated
green.
Due to these long time constants necessary to track
a 1pps input, temperature variations can cause
fluctuations in the relative phase of the 10MHz
output and the 1pps output.
The ∆ f/f tracking range of the internal Rubidium
oscillator is approximately ±1x10
source is in error, but within these limits, the
2960AR/2965AR will adjust to your source. This
allows multiple units to by synchronized even in the
absence of an absolute reference.
CAUTION:
Do not connect the 1pps input and 1pps output on an
instrument together. This will force the instrument to
track a moving value and reach its adjustment limit.
5.6 The 2960AR and 2965AR are configured for
automatic self-calibration. When continuously con-
nected to a stable 1pps source, they will auto-save
the disciplined frequency value into non-volatile
calibration memory every 24 hours. The last-saved
value will be used at next power on or when 1pps is
lost. The 1pps output of a calibrated and tracking
2960AR or 2965AR has lower jitter than a typical
GPS receiver making it suitable for use as a master
oscillator for further 1pps systems.
6.0
PERFORMANCE TEST
6.1 The performance test detailed below verifies the
functions of the 2960AR and the 2965AR.
Verification of the frequency and frequency stability
of the 2960AR or 2965AR requires a laboratory
environment of 23
NOVATECH INSTRUMENTS, INC.
NOTE:
NOTE:
-8
. If your 1pps
NOTE:
o
o
C
5
C.
±
6.2 See Table 3 for a list of recommended test
equipment to perform the following measurements.
Table 3: Recommended Test Equipment
Item
Specification
Oscilloscope
300MHz, 50Ω
Frequency
100MHz, 12-
Counter
Counter Time
Base
6.3 Verify Frequency Accuracy. To verify the fre-
quency of the 2960AR or 2965AR, set the frequency
counter to display 12-digits of resolution. The fre-
quency counter must use an external time base of
accuracy better than ±1x10
6.4 Verify the correct frequency at each output (for
2965AR, also verify at the frequencies in Table 4).
Allow the counter to average several readings. See
Table 4 for frequency error limits.
6.5 Amplitude Verification. Establish a measure-
ment function of Volts RMS on the oscilloscope.
Connect a 50Ω coaxial cable from the 2960AR or
2965AR to the oscilloscope (set to 50Ω termination)
Verify an amplitude of 1.0Vrms±0.25Vrms on each
output.
6.6 This concludes the verification of the 2960AR.
6.7 To verify the synthesizer output on the 2965AR,
install the 2965AR as directed in the Serial Opera-
tion part of Section 3. Connect your host controller
and operate the 2965AR per Section 4. The test lim-
its assume a stable environment of 18-28
6.8 Output Flatness Verification. (2965AR syn-
thesizer output only). Set the 2965AR to the values
of Table 4. Using the Vrms measure of the oscillo-
6
2960AR/2965AR Manual, 13-Jul-2004
Minimum
Recommended
Tektronix
termination
TDS3032B
HP53132A
digits.
-11
Novatech
<±1x10
Instruments, Inc.
Model 2965AR
with GPS1 smart
antenna.
-11
.
o
C.
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