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1.0
DESCRIPTION
1.1 The Models 2960AR and 2965AR are rubidium
frequency standards which can be disciplined to an
external 1pps (one pulse per second) reference sig-
nal. This 1pps is commonly derived from primary, or
other standards, such as GPS (global positioning sat-
ellite). When disciplined to 1pps, the 2960AR and
the 2965AR provide primary standard accuracy and
stability.
1.2 The 2960AR provides three fixed frequency
outputs of 10MHz, 10MHz and 5MHz, while the
2965AR replaces one of the 10MHz outputs with a
programmable 50MHz synthesized output. The
2965AR is particularly useful in applications which
require non-standard or customer specified frequen-
cies. The synthesized output is locked to the internal
rubidium oscillator and has the same accuracy as the
10MHz and 5MHz outputs. All outputs have a nom-
inal amplitude of 1Vrms into 50Ω.
1.3 The most recent version of this manual can be
found on Novatech Instruments, Inc. web site.
2.0
SPECIFICATIONS
2.1 FREQUENCY STABILITY (∆f/f)
Short Term:
t=1s
t=10s
t=100s
Aging:
Monthly
Yearly
Holdover (24Hours, ±2
>10x 1pps tracking time constant)
Temperature: +5 to +45
Line Voltage: ±10%
2.2 FREQUENCY ACCURACY
At shipment: <=±5x10
Retrace:
<=±5x10
1hour ON and 24hours OFF (constant environment).
2.3 FIXED SINEWAVE OUTPUTS
10MHz and 5MHz, 1V
(10MHz, 10MHz and 5MHz for 2960AR)
NOVATECH INSTRUMENTS, INC.
-11
<3x10
-11
<1x10
-12
<3x10
-11
<±5x10
after 1 month
-10
<±5x10
after 3 months
o
-11
C): <±1x10
(<±1µs after
o
-10
C <±1x10
-12
<±5x10
-11
o
at 20
C.
-11
from last frequency after
±0.25V
into 50Ω.
RMS
RMS
2.4 SYNTHESIZED SINEWAVE OUTPUT
(2965AR only, typical)
Frequency programmable from 100Hz to 50MHz in
1µHz steps.
Amplitude: 1V
RMS
(±3dB from 100Hz to 50MHz, referenced to
10MHz).
Phase Noise:<-140dBc, 10kHz offset, 1MHz output.
Harmonics: <-45dBc, spurious: <-55dBc.
2.5 SPECTRAL PURITY (10MHz outputs)
Harmonic <-25dBc.
Spurious/Non-Harmonic/Sub-Harmonic: <-45dBc.
2.6 PHASE NOISE (Typical, 10MHz output, 50Ω)
Frequency Offset dBc
1Hz
-70
10Hz
-90
100Hz
-120
1kHz
-140
10kHz
-140
2.7 1pps IN and OUT
1pps IN: DC-coupled, accepts TTL or CMOS. 1pps
OUT: TTL, 133µs negative pulse width. Typical
output jitter: 20ns peak-peak (1 minute measure-
ment time). (differential RS422 output optional)
2.8 ENVIRONMENTAL
o
Temperature: +0
C to +50
Humidity:
80% to 31
o
50% at 40
C.
2.9 SIZE
6.4cm H, 18.5cm W, 24.1cm L, excluding bail and
feet.
2.10 CONNECTORS
BNCs on front panel for sine outputs. BNCs on rear
panel for 1pps I/O. DE9 on rear panel for
synthesizer RS232 serial interface (2965AR only, no
connect for 2960AR). A serial cable is provided
with the 2965AR.
2.11 LINE POWER
120/240VAC ±10%, 50/60Hz. 30VA (50VA max
during warm up <20minutes).
2
2960AR/2965AR Manual, 13-Jul-2004
±0.25V
at 5MHz into 50Ω
RMS
o
C operating.
o
C, decreasing linearly to
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