the smallest and simplest GPSDO, based on U-blox LEA M8F module, 202102 version

Description

the version added I2C and FP connector;
the smallest and simplest GPSDO, based on U-blox LEA M8F module (include high performance VCTCXO, please check the pciture, the M8F is more thick than other M8 seris since it use a high stability VC-TCXO),
for the GPSDO, it is not only GPS, actually is GNSS, the O is VCTCXO;
within the Ublox U-center software, you also can select other satellite system, just like the Galileo (use
PHM), Glonass (use CS clock), but, you must make sure they are in stable working status, the prefer system is
GPS, now also use CS clock;
weight only 17g, size is 62x38x14mm(LxWxH), uses the USB port for power and data communication (Ublox u-
center), 3 RF ports are (all SMA interface):
one GPS port, pls connect the active GPS antenna (3.3V), you can use my shop's Pctel antenna;
one 1pps port, the port in default setting is 1pps, but you can set it by u-center from 1Hz to 24MHz, please
check the test diagram for 12MHz output, all the setting will be saved in the EEPROM,
please be aware the setting frequency should be divided by 24MHz (24,000,000Hz), just like 1Hz, 2Hz, 3Hz, 4Hz, 8Hz, 10Hz, 2MHz, 4MHz, 8MHz, 12MHz, 24MHz etc, if not, just like 10MHz (10,000,000Hz), may generates big tolerance;
one port is reference output, 30.72MHz, fixed, check the attached test result;
all the specification pls search google;
the kit include:
one GPS board;
one user guide (soft copy);
please be aware since I need to use the ultrasonic washing the soldering flux by
isopropyl alcohol, the U-blox label may not so clear.
ship to US (all 50 states) by USPS. other country pls contact me if can ship. please do not forget give me feedback if you enjoy it.