I have for your consideration, this new, Arduino based GPSDO. It uses a UBLOX Neo-M8N GPS to control a CTI OSC5A2B02 OCXO. This is a new build using US sourced (Mouser) components and shipped from the USA. The 10 MHz Square Wave Reference Signal can be used to control your frequency based test equipment or radios. It has an exceptionally clean, low phase noise signal that is accurate to approximately 0.001Hz. The nice compact aluminum enclosure comes in at 4.25”x4”x1.5”.

Also included is a 10MHz Band Pass Filter that can be used to convert the square wave into a sine wave.

The PLL control is accomplished using an STM32F411 Arduino Board. It has a 0.96” OLED display that shows the frequency, GPS coordinates, altitude, 3.3v & 5v rail values, number of locked satellites, uptime, time & date, and current pwm value. The STM32 board is pre-programmed to output a GPS sync’d time using an optional TM1637 as well as providing serial data output using an HC-06 BT module. The bluetooth module can be accessed via computer or phone and will constantly update with the information shown in the last picture (frequency, temperature, pressure, etc…). The PCB has the pinouts for the clock and Bluetooth module so both can easily be added as a future upgrade.

This is a really feature packed GPSDO and makes an excellent comprehensive reference source for your lab. With it, you’ll always have an exact to ~0.001Hz 10MHz reference signal with the ability add to add remote monitoring from your phone or computer as well as a reference time source.

To setup for use: connect and place antenna in area with good view of the sky and plug in the unit.

What’s included: GPSDO, power cord, GPS antenna.

What’s NOT included: any additional hardware shown for demonstration purposes (frequency counters, oscilloscopes, etc). Anything not specifically listed in “What’s included“