[GPS_Standard] GPSstd_PLL testing: V0.13 with an improved State Machine 2

[Bob Stewart]

Here I am running a test on what is essentially an upgraded Version 0.13 with a slightly improved State Machine 2.  Jim had asked me to run a long test of the one with just State Machine 1 that I posted previously, but this will have to suffice for now.  The performance should be more or less the same as V0.8 since the Adafruit receiver doesn't have the wild phase jumps on the 1PPS signal that come from the UT+ that I was trying to tame.  I've decided to run this until at least tomorrow morning.   So I'll update it then.

http://www.evoria.net/AE6RV/GPSstd_PLL/Plots/SM1SM2.30hrs.png

Just as a reminder, this is with using an Adafruit Ultimate Breakout GPS Receiver with the antenna near the peak of the attic.  There is a PN2222A serving as an amp/inverter in the 1PPS line, as the Adafruit doesn't have enough drive to provide a reliable TTL signal to the 18F2220.

For test equipment, I am using a Prologix Ethernet GPIB adapter and an HP 5334B to provide the phase timing.  The 10MHz signal from Bert's board is serving as the timebase for the 5334B.  The 1PPS signal goes to the A Channel and the 10MHz output from Bert's board (different port from timebase) is going to the B Channel.  The mode is TI A->B, which measures the time interval from the rising edge of the pulse on Channel A (1PPS) to the rising edge of the next pulse on Channel B (10MHz from Bert's board).  The monitoring software is home-grown.


Bob - AE6RV