Re: Quick and dirty GPSDO build by F2DC and me.
|
Interesting - I have a pile of old Motorola Oncore M12 GPS modules. They are all EOL due to the data roll-over issues but does anyone know if I can still use them for the 1PPS output? Thanks, Larry
On Tuesday, May 11, 2021, 11:05:56 a.m. EDT, Erik Kaashoek <erik@...> wrote:
Anyone looking for a GPSDO with a frequency accuracy in the order of 1e-8 should have a look at this:?
I made a quick and very dirty build of his design using only 4 modules found on eBay - Arduino nano - GPS module with 1PPS output (neo-6M or better, I used neo-7M) - SI5351 module with 3 outputs - 16x2 LCD display and some wires etc,?running from a bench 5V supply. The Arduino SW was modified (??) to have a adaptive measurement time depending on the frequency error observed. With a stable temperature of the SI5351 crystal and the largest measurement/correction cycle time of 400 seconds the stability was better than 0.01 Hz, or 0.003 PPM? The schematic as published by F2DC My current SW on github does not need the serial data from the GPS, only the pulse per second. The CLK1 output of the SI5351 is freely configurable to any valid SI5351 output frequency such as 10MHz or 100MHz.? Have fun -- HBTE Files section:?/g/HBTE/files Erik, PD0EK |