Users manual
N4430-O-G
Revision #:
B
Date:
8-23-18
Page
4
of
74
1.0 Summary
The NR4430-GNSS is a GNSS locked 10 MHz Frequency Reference with auto-
calibration.
Compact GNSS locked reference designed to be easily integrated into your system
to provide precision 10 MHz, PPS and NMEA for master timing. The unit features a
26 channel high-sensitivity, high-accuracy Multi-GNSS receiver. Supports TRAIM,
GPS, GLONASS, QZSS, SBAS, Active Anti-Jamming and Advanced Multipath
Mitigation Functions. Digital control loop provides low close in phase noise and
pulse to pulse jitter on the PPS of less than 1 ns. Auto-calibration stores the most
recent compensation coefficients dramatically minimizing long-term drift. A single 5
Vdc power supply simplifies system integration. Status signals alert the system to
BIT failures or loss of GNSS signal.
The signal source is a GNSS disciplined OCXO, actively controlled by complex
algorithm designed to minimize frequency error and PPS jitter. The 10 MHz sine
output is sourced from an intrinsically low jitter voltage-controlled crystal oscillator.
The calibration feature continually monitors the correction coefficients developed
through GNSS timing information. These are sampled multiple times per day and
stored in non-volatile memory and in the event of a GNSS loss, the saved
coefficients are applied to the OCXO. This effectively eliminates long-term crystal
drift.
There is an extensive built-in test loop that drives two LEDs and a single buffered
status bit signal from the 10-pin connector offering the ability to remotely monitor for
fault or loss of GNSS lock. There is also a GNSS lock status signal (and LED), PPS
and a serial port to provide access to NMEA time stamp data.
All inputs and outputs are electrostatic discharge protected. Any output can be
shorted indefinitely with no permanent damage to the unit.
