[GPS_Standard] My GPSDO Version 0.8 - speedup time-to-lock avaliable

[Bob Stewart]

Hi everyone,

An offline comment by Dave Platt motivated me to do something about the hour and a half it takes to go from powering on a newly burned PLL chip to locked mode.  The speed improvement is enormous.  Before this change, I was looking at about 1 hour 45 minutes to go to locked mode.  With this new code, the most recent power-up test took about 16 1/2 minutes.  I also increased the "L" parameter to 0x60, which should result in an accuracy of around +/- 1E-9 when it goes into Locked Mode.  A side effect of this improvement is that the "F" and "N" parameters are now unused.  They will be removed completely in the next release.

The new code is Version 0.8  can be found at "http://www.evoria.net/AE6RV/GPSstd_PLL/"  Next I will be working on the phase oscillations near "best solution" caused by the Motorola Oncore UT+ GPS receiver's sawtooth.  NOTE: "Best solution" is where the GPSDO is as near as it can be to exactly 10MHz, ignoring the effects of OCXO stability, timing receiver sawtooth, the size of the DAC in bits, etc.

Bob - AE6RV