Description

Low-jitter GPS-locked frequency clock source with 2 outputs with one as selectable PPS output. 1 Hz to 1.4 GHz output.

An upgraded version of the popular 2 Port Low Jitter GPSDO by Leo Bodnar Electronics

Long term stability of output signal is defined by high accuracy of GPS onboard Caesium references and approaches 1x10^-12
Output phase noise is shaped by high quality internal TCXO clock source providing clean clock signal with sub-picosecond RMS jitter.
Multi-loop digital-analog PLL allows output reference frequency to have almost any value between 1 Hz and 1.4 GHz on Output 2 and between 1 Hz and 800 MHz on Output 1 with infinite resolution eg: 144800000.025Hz N
LBE-1421 can often be pushed to operate beyond its guaranteed frequency range - all the way up to 1.5 GHz.
Output signal is a square wave at 3.3V CMOS levels with 50 Ohms source impedance. It can be used directly by most instrumentation and RF equipment.
Output power level (measured at 10MHz, fundamental power channel): +11dBm
Typical phase noise at 10MHz output:
72 dBc/Hz at 1 Hz
101 dBc/Hz at 10 Hz
128 dBc/Hz at 100 Hz
147 dBc/Hz at 1 kHz
156 dBc/Hz at 10 kHz
159 dBc/Hz at 100 kHz
164 dBc/Hz at 1MHz

Power draw through 5V USB is 250mA max.
Rise/fall time of output signal at 10MHz is 300ps/260ps measured between 10% and 90% levels.

Operation requires presence of GPS signal, however temporary satellite signal loss is handled seamlessly with no frequency or phase jumps. Active or passive antennas are supported. An active antenna with 5 metre cable is provided with the device but can be substituted if necessary. GPS acquisition time after power-up is around 30 seconds. If GPS signal is lost, digital PLL will maintains best estimated output frequency based on historical data. On reacquisition of GPS lock, output is seamlessly brought back in sync with GPS reference. Entry and exit of frequency hold is glitch-less.

Frequency setting is configurable via USB connection from Windows PC.

Satellite signal NMEA data telemetry is available via virtual serial port over USB connection.

GPS clock can be powered via USB-C connector from a PC, USB charger or USB power bank. USB connection to Windows PC is required only for one-off configuration. All settings are stored inside the device and maintain values when off. The SMA antenna connector voltage is 3.3V. Most active antennas marked as 3.3V or 5V will work.

The LBE-1421 GPS Locked Clock Source can be used as an Universal Reference Clock for most other Instruments and Applications which up to now would require a bulky and expensive Rubidium Clock.

SDR-Kits recommends the unit as the ideal frequency standard for supplying an external reference clock signal to the DG8SAQ Vector Network Analyzer to make Frequency and Frequency Difference measurements with accuracy approaching 1e-10 and frequency measurements (dF) in the mHz (milli Hertz) and even down to the uHz (micro Hertz) region.

Also, the LBE-1421 GPS Locked Clock Source can be used as an external clock for the SDRplay RSPdx-R2, RSPduo and the older RSpdx, RSP2 or RSP2pro models with our SMA Plug to MCX Cable for SDRPlay RSP SDR Receivers

Please see comparison table below listing the differences between the two GPSDO models:

Feature	LBE-1420 GPS Locked Clock Source (1 Output)	LBE-1421 GPS Locked Clock Source (2 Outputs)
Stability	+1E-11 within 1 min after GPS Lock	+1E-11 within 1 min after GPS Lock
Frequency Range	1 Hz – 1.1 GHz Output fractional resolution in steps of 0,001 Hz steps guaranteed but may be pushed up to 1.5 GHz	1 Hz – 1.4 GHz Output Fractional resolution of 0.001 Hz steps guaranteed but may be pushed up to 1.5 GHz
Reference Clock Outputs and Connector Type	1 SMA Output Connector 3.3V 50Ω CMOS Square wave	Output 1: SMA 1Hz-800 MHz 3.3V 50Ω or 1 PPS Square Wave Output 2: SMA 1Hz-1.4GHz 3.3V 50Ω Square Wave
Output Level	Square Wave +11 dBm at 10 MHz Low Power mode -2dBm	Square Wave +11 dBm at 10 MHz Fundamental Power Low Power mode -2dBm
USB Power Supply	USB-C Connector USB 5V max 250mA	USB-C Connector 5V 250mA max
External Power Supply	USB-C +5V Max from +5v Powerbank	USB-C +5V max from PC or from 5V Power Bank
Dimensions	69mm x 40mm x 12mm 0.03 Kg	69mm x 40mm x 12mm 0.04 Kg
Package Contents	LBE-1420 GPS Locked Clock Source, GPS Antenna, USB C Cable	LBE-1421 GPS Locked Clock source, GPS Antenna, USB C Cable
Typical Application	Clock Source for applications requiring a single Reference Clock	Ham Station Reference Clock Source 10 MHz for Test equipment and 24 MHz for RSP1 or K3 or other Rigs

How to make high accurate precision frequency measurements with the VNWA Thanks to Kurt Poulsen for preparing this report and sharing his expertise.

How to set up the LBE-1421 as an External Clock Reference for the VNWA 3EC/3SE: Guide to setting up LBE-1421 as external reference clock, instead of internal VNWA TCXO when taking VNWA measurements

Linux Support: A Linux Configuration Application is available from https://github.com/hamarituc/lbgpsdo

Package Contents:

GPS Locked Clock Source module (69mm x 40mm x 12mm - 0.04Kg)
GPS Magnetic Antenna with 5m Coax Cable and fitted SMA male plug

USB-C cable

24 month Mfg Warranty
Mfg Product Support information

Optional Items to add to your order:

RG223 cable Length 20 cm BNC Plug (male) to SMA Plug (male)
This is a custom made cable to connect the VNWA 3EC External Clock input to the Precision GPSDO Reference Oscillator

Replacement GPSDO Antenna: Cable length 5 m, fitted with SMA Plug (male) connector
This is a replacement or additional GPS Antenna identical to the one supplied with the LBE-1420 + 1421 Locked Clock Source

SMA Plug to MCX Cable - External Clock Cable for use with RSP Rx

SDR-Kits is an Authorised Distributor for the Leo Bodnar Ltd Precison GPSDO Reference Oscillator

Also available from our Authorised Distributor for Japan: ICAS Enterprises www.ICAS.to