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Triple Channel Rubidium Reference with GNSS Locking and Low Noise Options All information provide herein is the proprietary property of Novus Power Products L.L.C. The information included may be reproduced without the permission of Novus Power Products L.L.C. without prior approval for purpose of operating the equipment.
3/17/2019 Summary The NR8403 is a three channel Rubidium source which options that include GNSS locking and Ultra Low noise. A low power Rubidium source and low power OCXO are used in the design to allow a compact design with little cooling air required. There is a fan that is modulated by the processor to handle worst case temperature conditions.
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Users manual NR8403 Revision #: Date: 3/17/2019 The base unit is standard Rubidium reference with no GNSS locking or phase noise enhancement. The Rubidium source affords a stability of < 3E-10/month. The unit consumes < 10 watts of power from a DC source that can be from -60 to +60 Vdc in three ranges.
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Users manual NR8403 Revision #: Date: 3/17/2019 The RS232 interface provides access to the NMEA-0183 data from the GNSS receiver at a baud rate of 38.4K. The baud rate can be changed through the RS232 port using commands described in the Output Format Section (8.0). In addition to NMEA data, the serial data also provides equipment status- The PPS pulse is capable of driving into a 50 ohm load at 5 volt logic levels.
Users manual NR8403 Revision #: Date: 3/17/2019 2.1 Power The equipment will need a power source of approximately 15 watts- Steady state power is < 10 Watts Power can be from an AC power adapter or a DC source. The...
Users manual NR8403 Revision #: Date: 3/17/2019 Power consumption is highest at turn-on as the crystal is warming up or if it is a very cold environment. Under normal conditions, warm is less than five minutes. Power max < 10 Watts Steady state power <...
Users manual NR8403 Revision #: Date: 3/17/2019 If 24 hour mode or 12 hour mode is chosen, the GMT offset will be applied to the displayed time. If GMT mode is selected, no offset will be applied to the displayed time.
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Users manual NR8403 Revision #: Date: 3/17/2019 To measure the range from the satellite to the receiver, two criteria are required: signal transmission time and signal reception time. All GPS satellites have several atomic clocks that keep precise time and are used to time-tag the message (i.e.
Users manual NR8403 Revision #: Date: 3/17/2019 knowing all satellite positions and measuring the signal transit times, the user’s position can be accurately determined. Mechanical 5.099 .150 .085 .499 1.053 3.043 1.720 2.382 6.291 6.101 .382 1.537 The 4 line display and two buttons provide status and control functionality.
Antenna Antenna 1 - SMA SMA female antenna connections. Provides internal 3.5VDC power at <30mA max. The Novus NA103 pole mount antennas or the Novus NA106 magnetic mount antenna are recommended for optimal performance. The receiver and companion elements generate the PPS and NMEA serial link.
Users manual NR8403 Revision #: Date: 3/17/2019 PPS (Pulse Per Second) The PPS (one Pulse Per Second) relationship with the NMEA data is shown below: The serial data timing is for the next rising edge of the PPS pulse. There are a number of attributes for the PPS that can be...
Users manual NR8403 Revision #: Date: 3/17/2019 The PPS may also be selected from an internal synthesizer operated from the 10 MHz. This source is much more stable with pulse-to-pulse jitter below 1 ns while being within 100ns of the received PPS.
Users manual NR8403 Revision #: Date: 3/17/2019 PPS holdover is concerned with the stability of the PPS when GNSS lock is lost. The circuitry discussed to improve jitter also improves holdover. If the oscillator is an OCXO - then a PPS drift of 5 to 10 ppb/day is achievable (<...
Users manual NR8403 Revision #: Date: 3/17/2019 Rear Panel NR8403 Novus Power Products LLC www.novuspower.com NMEA Power 10 MHz Channel Output – BNC (10MHz Option) There are three 10MHz output on the rear panel, BNC 50Ω Antenna Input - SMA SMA female –...
Users manual NR8403 Revision #: Date: 3/17/2019 The unit is designed to operate from 12 VDC nominal power and is reverse polarity protected. Pin 1 is designated on the panel and is the far right pin as directly viewed. 3.4 RS232 DB9 (Status and NMEA) An RS232 port is provided for NMEA output from the GNSS receiver, and for the optional status of the 10MHz source .
Users manual NR8403 Revision #: Date: 3/17/2019 Operations At the application of power the Rubidium begins its lock process. The locking time is typically less than 5 minutes. If the low noise OCXO option is purchased then the OCXO must lock to the Rubidium. The OCXO has its own warm-up time illustrated below.
Users manual NR8403 Revision #: Date: 3/17/2019 would continue to monitor each channel and a deviation beyond the set limits would be reported as a failure on the front panel and via RS232. The Channel Status feature can quickly detect a cabling failure. Any change in the load impedance will change the output voltage with respect to the divider formed by the output impedance of the amplifier and the load impedance.
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Users manual NR8403 Revision #: Date: 3/17/2019 The output channel has a Reference Voltage which can be set by latching the channel’s current value in the Latch Channel Average Screen. The output reference voltage can be set individually by writing the value serially with the $SET command.
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Users manual NR8403 Revision #: Date: 3/17/2019 The Alert Threshold can be optimized so that a channel short or an impedance change will cause an Alert. Example: Page #: 23 of 37 www.novuspower.com...
Users manual NR8403 Revision #: Date: 3/17/2019 The output of channel 1 is connected to a high impedance input and reports 1.25Vrms at the output. Alert threshold is set to +/-20%. The current state is saved in the Save Configuration screen.
Users manual NR8403 Revision #: Date: 3/17/2019 Save Configuration The Save Configuration screen allows the user to save the current settings for Alert Threshold, Input Threshold, Attenuation, Input Select, Reference Voltage and any other settings that have been modified via the RS232 port.
Users manual NR8403 Revision #: Date: 3/17/2019 communication failure would be indicated by a “Com FAIL” indicator. Either of these fault statuses will result in the change of the primary to the backup system. The individual statuses of the internal power supplies are also available via the RS232 serial port.
Users manual NR8403 Revision #: Date: 3/17/2019 Functional Description Outputs Each output is fault and electrostatic discharge protected. Each output is independent and any output can be faulted for an indefinite period of time with no permanent damage. Each output is connected to a monitor circuit that detects a local fault on the output.
Users manual NR8403 Revision #: Date: 3/17/2019 Linear Amplifier Built in Test There are number of power supplies in the design to meet special needs and noise reduction. All power supply voltages are monitored, and can be accessed via RS232 or ethernet. In addition, all current channel statuses, or Vrms values, can be monitored, as well as power supply health.
Users manual NR8403 Revision #: Date: 3/17/2019 port, a unit configured with the serial to ethernet option can access these commands. If the user makes changes which are intended to be kept between power off cycles, the command “$SAVEFLASH*51 <cr><llf>” will update flash to reflect all current settings.
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Users manual NR8403 Revision #: Date: 3/17/2019 REFERENCE combination with the Channel Fault Threshold VOLTAGE Factor to define Alert on an individual Channel. Reference Voltages are set with respect to the active input, allowing for variation in amplitude between Input A and Input B.
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Users manual NR8403 Revision #: Date: 3/17/2019 appropriate measurement parameters. These settings should only be changed by an authorized $CAL1=11.10 technician. SAVE ALL CAL This command will translate all Calibration Factors $SAVED CAL. FACTORS TO $SAVECAL to flash string and write. Data is then read back for $SAVE CAL FAILED.
Users manual NR8403 Revision #: Date: 3/17/2019 Technical Specification Output 10 MHz,0.5 Vrms ±0.2, into 50 Ohms Accuracy at Shipment <1E-9 Monthly Aging <2E-11 after 3 months of operation Yearly Aging <1E-9 after 3 months operation (unlocked) Locked <5 E-12 Harmonic Distortion <...
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Tracking: -157 dBm Hot Start: -157 dBm Warm Start: -143 dBm Cold Start: -143 dBm Reacquisition: -157 dBm With Novus recommended antenna Antenna with LNA Antenna power 3.5 Vdc, < 35 ma (on center conductor) (factory configurable to 5 Vdc) Frequency...
(a) NOVUS is notified in writing by Buyer of such defect prior to the expiration of the warranty period, and (b) after receiving return authorization –RMA- from NOVUS, the defective item is returned with transportation prepaid to NOVUS, St.
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Should Novus be unable to repair or replace the product within a reasonable amount of time, the customer’s alternate remedy shall be a refund of the purchase price upon return of the product to Novus. The liability of NOVUS under this warranty is limited to replacing, repairing or issuing a credit, at its option, for any such item returned by Buyer under the terms of this warranty.
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