USERS MANUAL
NR2310-O/G
REVISION
H
DATE
7/17/20
Page #:
5 of 21
www.novuspower.com
By virtue of having a very low bandwidth, the high frequency jitter is dramatically
reduced. There are numerous tradeoffs - speed of acquisition, phase error,
stability, cost, etc. It is a complex feedback loop and as such, there are many
solutions. Noise on the final output is also affected by the noise in the system.
Noise from power supplies and other circuits can easily sum with the output
signal. Care has been taken throughout the design to achieve a high-quality
signal.
The phase noise of the output is now largely dominated by the voltage-controlled
oscillator. The oscillator is typically a crystal oscillator and the quality of that
device can vary significantly. The NR2310-O/G uses an oven-controlled oscillator
to provide an unlocked stability of under ±50 ppb/year.
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 GPS loss, the saved
coefficients are applied to the OCXO. This effectively eliminates long-term
crystal drift.
The NR2310-O/G also incorporates built-in test to monitor critical parameters
such as the OCXO oven, power supplies and other functions. The built-in test
drives a front panel indicator and status is available via the RS232 port.
The GPS lock status is provided by a front panel indicator and via the RS232
port.
The NR2310-O/G draws less than 10 Watts of power.
The output of the OCXO is buffered and amplified. The buffering is completely
fault protected and is followed by ESD protection circuitry. The output is also
monitored for signal presence.
In addition to the signal presence built-in test, there is circuitry to determine if the
oven within the OCXO has failed. This is a very subtle failure as there would
appear to be a sine wave - but without a functional oven, the temperature stability
would be poor. If a failure is detected, the Alert LED will be activated and the
status relay will be opened. During the first fifteen minutes of operation, an alert
may occur as the oven brings the crystal up to temperature. This is normal and
will stop after approximately fifteen to thirty minutes of operation.
