Are they running off the same power supply? If so, I would run them from different power supplies as an experiment. --- Graham
== On Tue, Dec 22, 2015 at 6:19 AM, Attila Kinali <att...@kinali.ch> wrote: > On Tue, 22 Dec 2015 11:57:55 +0100 > Mike Cook <michael.c...@sfr.fr> wrote: > > > > A sampling difference of 1 cycle with 48Mhz clocks would give you ~21ns > > offset if not using sawtooth correction. Can you do the sawtooth > correction > > and see if the offset is reduced? > > This is the most likely explanation. The LEA-6 modules use a 24MHz > oscillator > which is doubled for the processor, leading to the 48MHz clock. > > > Good thinking Brian. But I would expect the difference to wander from > 21s > > UNLESS the the two receivers clocks are lock stepping. Injection locking > > might do this if the two module are physically close enough. > > Injection locking wont work by simply playing the modules close to > eachother. > The oscillators are shielded well enough that quite some injection energy > would > be needed. Unless the TIMEPULSE2 output of one module is used to generate a > 8MHz signal which is directly injected into the power suplly of the other, > i > don't see how injection locking would work. And even then, I wouldn't be > sure > if injection locking could be acheived. > > What could be done, though, is to lift the shield over the cpu side of the > LEA-6, unsolder the oscillator and use an external 24MHz oscillator to > supply both LEA-6 modules. > > If you do this, you could even go as far as to use the sawtooth correction > message to stear the reference oscillator. That way you wouldn't need to > measure the PPS output and could to a "fully" digital control system > instead. > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.