Racal Instruments

Racal Instruments
Racal Instruments
Time and Frequency
Distribution System
Model 9480
Modular Design Features Plug-In Power
Supply and Output Cards
Up to 40 Buffered Frequency Outputs
Ovened or Atomic Standard Options
The 9480 Time and Frequency
Distribution System is a modular
frequency standard, time standard,
and distribution system. It offers a high
degree of flexibility for designers of
calibration/repair facilities, satellite
systems, test systems, and other
applications requiring distribution of a
frequency and/or time standard.
System capabilities vary from a simple
5-output distribution amplifier card to a
complex frequency standard with
multi-frequency outputs referenced to
both primary and secondary
With field-upgradable options, the
9480 enables users to “build up” the
system over a period of time at
minimum expense.
The time and frequency mainframe is
the heart of the 9480 system.
AC or DC Operation
1 Pulse-Per-Second and Reference
Monitor Outputs
Optional Redundant Frequency
Changeover and Battery Backup
It houses both the power supply and
frequency-management sub-system.
The mainframe has the capacity for an
oven-controlled crystal oscillator or a
rubidium frequency standard, an
optional battery backup supply, and up
to eight, 5-output, distribution amplifier
cards. Up to 40 outputs can be
distributed from one mainframe.
The instrument operates from a wide
range of AC power voltages with the
ability to additionally operate via an
external DC supply. Upon AC power
failure, the unit automatically switches
to the external DC supply (if
connected). Users may add an
optional battery backup capability for
maintaining power to the frequency
standard in absence of both the mains
and external DC power. Front-panel
indicators designate which power
source is in use.
The 9480 series offers a 1-pulse-persecond and 10 MHz output on the
front panel. In addition, users may
select five-output distribution amplifier
cards with output frequencies of
100 kHz, 1 MHz, 5 MHz, 10 MHz,
13 MHz, or 2.048 MHz.
The Model 9480 is ideally suited to
almost any requirement for a precision
time reference, frequency reference,
and/or distribution system.
When used for UHF Quasi-Sync or
Simulcast system testing, the flexible
number of outputs and frequencies
remains ideally suited for phaselocking transmitter/receiver base
stations. The rubidium standard
achieves the desired stability without
the need for frequent oscillator
calibration or expensive environmental
control. When used for satellite ground
stations and calibration laboratories, a
wide-range of options, including
specialized low-noise standards, are
Selecting A 9480 System
When selecting a frequency and/or
time standard and distribution system,
consider the following:
• Frequency standard performance
• Power supply requirements
• Number and frequency of outputs
Using the 9480 With External
Frequency Standards
The 9480 series can be used as a
frequency distribution system fed by
an existing external standard. Users
may additionally install an internal
standard (see below) as a back-up
reference. The 9480 will then
automatically switch to its internal
standard if the external input is lost,
fails, or is removed for calibration.
Internal Standard Options
The 9480 series offers a range of
frequency standard options suited for
internal fitting. They include an ovened
crystal oscillator, low-phase noise,
high stability, and a choice of highlystable rubidium standards.
When selecting a frequency standard,
consider the following parameters:
• Aging
• Short-term stability
• Phase noise
• Retrace
Aging refers to the process by which
an oscillator’s frequency changes with
time, specified in fractions of a Hertz
per time period. Also known as longterm stability, aging specifically refers
to periods of one day or more.
Figure 1. Typical Aging Characteristic
In general, aging occurs exponentially
and is greatest during the first month
of operation. Figure 1 depicts the
typical accuracy characteristic of a
high-stability, ovened crystal oscillator
in the first year of operation
In some instances, high-quality crystal
oscillators may not be sufficient for
applications such as UHF quasi-sync
or Simulcast Systems, where
accuracies approaching 1 x 10-9 are
required. Such accuracies are
achievable with a crystal but will
require frequent adjustment and
careful temperature control. In
contrast, a rubidium oscillator would
only drift by 1 x 10-10 per year.
Although rubidium standards are more
expensive than crystal oscillators, they
maintain a longer calibration cycle than
crystal, which can save costly
calibration downtime.
Short-Term Stability
Short-term stability is the
characterization of oscillator-frequency
changes over periods shorter than
100 s.
An Allan Variance calculation is often
used to characterize the short-term
stability of precision oscillators. This
statistical method presents the
average variance in frequency over a
given time and selected sample
Many reference oscillators, particularly
quartz, experience a frequency offset
known as retrace error, caused by
removing and re-applying power as
described in Figure 2.
Figure 2. Retrace Error
In order to prevent retrace error, the
9480 can be fitted with an internal
battery option, which maintains supply
to the oscillator in the event of the loss
of unit power.
Available Standards
04A is a fast warm-up, oven-controlled
crystal oscillator with an aging
characteristic of 3 x 10-9/day; warmsup in less than 6 minutes.
04F is a precision oven-controlled
crystal oscillator combining
2 x 10-10/day aging with very low phase
FR-LP is a new, low cost, highly stable
rubidium atomic oscillator with a onemonth drift of 5 x 10-11; warms-up in
less than 11 minutes.
Phase Noise
Phase noise measures the random
fluctuations in frequency or phase due
to noise. It is normally measured in a
1 Hz bandwidth at various offsets from
the fundamental frequency. The
standard generates close-to-carrier
phase noise. At offsets of 1 MHz or
more, noise may occur due to the
frequency distribution system. The
9480 was designed with special lownoise amplifier technology throughout
to minimize phase noise.
FRK-H is an ultra-stable rubidium
atomic oscillator with a one-month drift
of 1 x 10-11.
Power Supplies
The 9480 Series has a flexible power
supply. Available configurations
ensure the maintenance of a
continuously power frequency
standard, thus eliminating retrace
problems. The primary power ranges
from 90 to 254 VAC; with power
absent, the unit automatically selects
an externally applied 23.4-30 VDC (if
present). If DC is absent, the 9480
selects the internal rechargeable
battery (optional) for maintaining
continuous power to the reference for
at least one hour.
Frequency and Number of
High Reliability
Racal has many years of experience in
the supply and manufacture of
frequency standards and distribution
systems. The 9480 series is
constructed with proven components
and assemblies. The power supply
module, distribution cards, and
external reference cards are all
pluggable enabling rapid fault
identification and minimal repair time.
There are up to 8 plug-in output
distribution cards at the year of the
9480 mainframe. Each output card
contains 5 buffered outputs available
in frequencies of 100 kHz, 1 MHz,
5 MHz, 10 MHz, and 13 MHz. Also
available are 2.048 MHz and 13 MHz
TTL output cards.
Front panel LEDs continuously monitor
and report output card status.
Dual Redundancy Configuration
When the availability of a frequency
standard is of critical importance, a
9480 system can be configured to
have both primary and secondary
external standards. In this case (see
Figure 3), by utilizing a reference
changeover card (RCO option), the
9480 automatically changes over to an
external secondary frequency
standard if the external primary
standard fails.
Future Expansion
Figure 3. 9480’s configured for high
availability of the Frequency Standards
using the RCO option.
The 9480 series allows future
expansion at minimal cost. For
example, if more outputs are required
then only additional output cards need
be purchased. Upgrading from a
quartz standard to a rubidium is also
possible, without the need to purchase
an additional mainframe.
Available Frequencies (sinewave)
100 kHz, 1, 5, 10, and 13 MHz
Available Frequencies (TTL)
2.048 and 13 MHz
Card Outputs (per card)
Channels: 5
Frequencies: 1
Mainframe Outputs (max)
Cards per Mainframe: 8
Channels per Mainframe: 40
Sinewave: +13 dBm ±2 dBm, 50 Ω
TTL: 5 V, nominal
< 1.3:1
Between Outputs: > 40 dB
Between Cards: > 60 dB
Output Protection
Short Circuit: Indefinite
Reverse Power: < 500 mW
Applied DC: < 30 V
Spectral Purity
Harmonics: < -35 dBc
Sub-harmonics: < -70 dBc
Spurious: < -70 dBc
Ovened Quartz (Option 04A)
Aging Rate: 3 x 10-9/day
Warm-up @ 25° C : < 6 min. to 1 x 10-7
Accuracy at Shipment: ±1 x 10-8
Ovened Quartz (Option 04F)
Aging Rate: 2 x 10-10/day, 3 x 10-8/year
Allan Variance: 5 x 10-11 over 10 s
Phase Noise: -145 dBc/Hz @
1 kHz offset
Warm-up @ 25° C : < 20 min. to 1 x 10-8
Rubidium FR-LP (Option FR-LP)
Frequency Drift: 5 x 10-11/month
Frequency Retrace: ±2.5 x 10-11
Allan Variance: 2.5 x 10-12 over 100 s
Phase Noise (1 Hz offset): -75 dBc/Hz
Phase Noise (10 Hz offset): -89 dBc/Hz
Phase Noise (100 Hz offset):
-128 dBc/Hz
Phase Noise (1 kHz offset):
-140 dBc/Hz
Phase Noise (10 kHz offset):
-147 dBc/Hz
Warm-up @ 25° C < 11 min. to 4 x 10-10
Rubidium FRKH (Option FRKH)
Frequency Drift: ±1 x 10-11/month
Allan Variance: < 1 x 10-12 over 100 s
Warm-up @ 25° C < 10 min. to 2 x 10-10
External Standard Input
Frequency (standard): 10 MHz
Frequency (Opt DIV): > 1 MHz,
sub-multiple of 10 MHz
Input Range: 100 mV to 1 Vrms
Maximum Input: 5 Vrms
Input Impedance: 50 Ω
Front Outputs
Monitor: 10 MHz, 0.3 Vpk-pk,
BNC, 50 Ω
1 PPS: 1 Pulse/second, 0.3 Vpk-pk,
BNC, 50 Ω
Front Indicators
Output Failure: One per output card,
flashes on failure
Frequency Lock: On when frequency
standard is locked
External Input: On when external
standard is applied
Power Source: Three (3) LED’s, AC,
DC or Battery
Alarm: On for any failed output.
Front Controls
Reset Button: Resets latched alarm
Adjust: Frequency standard fine
adjustment (recessed)
Rear Inputs
Option PSO
External Reference (standard): BNC,
10 MHz
External Reference (opt DIV): BNC,
≥ 1 MHz, sub-multiple of 10 MHz
Diagnostic: 9-pin D-Sub, reset,
AC/DC*, Osc. Lock, Rb control,
Ext. Ref. Present, Batt. On, Alarm
DC Input: 2-pin, polarized connector,
fused, reverse-protected
AC Input: 90-254 V, fused
Power-supply service option allows
removal of PSU for service without
power loss to the 9480
Option RCO
Reference changeover option when
primary and secondary external
references are used
Option DIV
Enables the use of an external
reference ≥ 1 MHz and a submultiple of 10 MHz
Option BBU
Battery backup maintaining power for
≥ 1 hour to the internal reference if
AC and DC power fail
Operating: 0° C to 50° C
Storage: -40° C to 70° C
95% RH @ 40° C
Without BBU: 33.5 lbs. (12.5 kg)
With BBU: 37 lbs. (13.8 kg)
Power Requirements
AC: 90-127 V, 193-254 V, 45-440 Hz,
60 VA max
DC: 23.4-30 VDC, 1.5 A max after
warm-up, fused, reverse power
BBU (optional): Internal rechargeable
5.37” H x 16.73” W x 18.52” D
CE, Mil-Std-461C, RE02 (<1GHz),
CE03, CS02, CS06, RS03
CE, EN61010-1
Voltage Range Selection
Rear panel switch
Accessories Furnished
19” Rack Mount, Handles, Power
Cord, User’s Manual
Part Number
Time and Frequency Mainframe
Example: Model 9480/FR-LP
2 x -10/-5/-BBU is a 9480 mainframe
with FR-LP rubidium standard, two
10 MHz output cards, one 5 MHz
output card and, battery backup
option. Supplies:
Frequency Standards
Option FRKH
High-Stability Rubidium Frequency Standard
Option FR-LP
Rubidium Frequency Standard
Option 04F
Low Phase Noise Oscillator
Option 04A
Fast Warm-up Oscillator
Option 10
5 x 10 MHz Output Card
Option 5
5 x 5 MHz Output Card
Option 1
5 x 1 MHz Output Card
Option 100
5 x 100 kHz Output Card
Option 13
5 x 13 MHz Output Card
• 10 x 10 MHz outputs
• 5 x 5 MHz outputs
• All with Rubidium, 5 x 10-11
• Battery backup capability
Output Cards
Option 13A
5 x 13 MHz TTL Output Card
Option 2048
5 x 2.048 MHz TTL Output Card
Option BBU
Battery Backup (> 1 Hour)
Option DIV
Allows integer divisions of an external 10 MHz to be accepted
Option RCO
Reference Changeover Card
Other Options
The CE Mark indicates
that the product has
completed and passed rigorous
testing in the area of RF
Electromagnetic Disturbances
and complies with European
electrical safety standards.
The Racal policy is one of continuous development; consequently, the equipment may vary in detail from the description and specification in this publication.
Racal Instruments, Inc., 4 Goodyear St., Irvine, CA 92618-2002. Tel: (800) RACAL-ATE, (800) 722-2528, (949) 859-8999; FAX: (949) 859-7139
Racal Instruments Ltd., 480 Bath Road, Slough, Berkshire, SL1 6BE, United Kingdom. Tel: +44 (0) 1628 604455; FAX: +44 (0) 1628 662017
Racal Systems Electronique S.A., 18 Avenue Dutartre, 78150 LeChesnay, France. Tel: +33 (1) 3923 2222; FAX: +33 (1) 3923 2225
Racal Systems Elettronica Srl, Strada 2-Palazzo C4, 20090 Milanofiori Assago, Milan, Italy. Tel: +39 (0)2 5750 1796; FAX +39 (0)2 5750 1828
Racal Instruments GmbH, Technologiepark Bergisch Gladbach, Friedrich-Ebert-Strasse, D-51429 Bergisch Gladbach, Germany. Tel: +49 2204 8442 00; FAX: +49 2204 8442 19
Racal Australia Pty Ltd., 3 Powells Road, Brookvale, NSW 2100, Australia. Tel: +612 9936 7000; FAX: +612 9936 7036
2.0 9-01
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