[time-nuts] PPS phase between two GPS units.

[Dan Kemppainen]

Hi all,

Thanks for all the responses.

The GPS units were swapped on the splitter ports, and the phase 
difference did in fact change. It changed from 21nS to around 5nS. Not 
exactly what was expected, although it would tend to indicate the RF 
path is not the same through the splitter.

Last night a 'symmetrical splitter' was made up using a mini circuits 
ZFRSC-42. Both of the outputs to the GPS units were AC coupled. A bias T 
was inserted directly on the antenna feed with external power feeding 
the new splitter antenna port.

The PPS's are now very close, about 1 nS average difference. If this 
holds solid, in a few days I'll swap splitter ports again.

Thanks,
Dan