Frequency Locking and GPS References
Using GPS in Amateur Radio
VE2ZAZ GPS Derived Frequency Reference - Bertrand Zauhar's PIC Based GPS based 10MHz standard working from the 1 PPS signal. Better short term stability than the simple GPSDO, but ought to be kept running continuously due to long lock-up time. Needs a good high spec ovenned 10MHz VCXO
Locking Microwave Local Oscillators
Reflock calculation
The original MSF Locked Frequency reference, Published in RadCom April/May 1994
Simple GPS Disciplined Oscillator
Low chip-count design using the 10kHz output from a Jupiter-T GPS module
An even simpler design
How GPS derived timing can be used for new data modes and for accurate frequency control.
This article first appeared in Radio Communication April 2006
GPSRadiotalk
Presentation given at the RSGB HF Convention October 2005
Simple frequency locking of local oscillators for microwave transverters using a sampling mixer
Frequency Locking Microwave sources
Generating arbitrary frequencies, accurately
Calculate the nearest R and N divider ratios for locking an oscillator for an integer-PLL synthesizer.
Fout = M * N * Fref / R
Specify wanted output frequency (Fout), RF multiplication (M), reference input frequency (Fref) and the minimum and maximum limits for the comparison freq. It will then go away and find the best values of R and N to minimise the resulting frequency error.
Part 1 ,
Part 2 - PDF Files
The Mark 2 version. More stable design with 5 or 10MHz reference output
Full Article
Circuit Diagram GIF file
