[time-nuts] 1 pps accuracy to UTC

[Martyn Smith]

Hello,

I may have asked this before, but still haven't got an answer.

The Motorola M12+ or M12M quote 20 ns accuracy to UTC.

I have two receivers running off the same aerial through a GPS splitter.

If I measure the 1 pps signals on my SR620 counter (single shot), they are 
up to 100 ns out.

They are never within 20 ns.

In fact even just 1 pps signal has about 50 ns jitter on it.

I've tried this on many GPS receivers.

So how can they quote 20 ns, when two of them are up to 100 ns out.

Has anything got good results from the 1 pps signal output?

Any ideas

Martyn