[time-nuts] Strange 100ns jumps on Motorola M12+T

Chris Albertson albertson.chris at gmail.com
Thu Nov 21 11:27:29 EST 2013


On Thu, Nov 21, 2013 at 12:49 AM, Stephan Sandenbergh
<ssandenbergh at gmail.com> wrote:
...
> Using a single antenna and splitting it is an idea, but then I still need
> to devise something to inject the antenna DC power at the other end of the
> splitter etc. And, we are trying to measure the relative offset between the
> antenna/receiver pairs for calibration.

Many splitters have a DC passthrough.  Even some cheap under $10
satellite TV splitters have this.
>From memory, I think you can disable the antenna supply on the Oncore,
you don't want all three GPSes trying to supply DC power.

I looked at the graph.  It is such a clean jump that I doubt this is
noise at the antenna.  Also it looks like 50nS of noise.  Seems to
much for an MT12-T.   Are they running in position hold mode?   Did
you do a long enough site survey?
-- 

Chris Albertson
Redondo Beach, California


More information about the time-nuts mailing list