[time-nuts] PPS delay on rockwell

[Brian Inglis]

On 2015-02-16 02:57, Hal Murray wrote:
>
> francesco.messineo at gmail.com said:
>> I can only suspect it was unlocked, but I need to setup all the test in
>> another place closer to the window, since I don't have a splitter to use the
>> same antenna of the thunderbolt.
>
> If one or both are unlocked, I'd expect them to drift, not rapidly, but I'll
> bet it's easy to measure if you wait a day.
>
> There is software to talk to TBolts so it should be easy to find out if it is
> locked.
>
> Have you tried any software on the Rockwell?  It may even talk NMEA so all
> you have to do is connect it to a PC and guess the baud rate.
>
> Or maybe upload a picture and somebody will recognize the model so you can
> google for details.

See http://gpskit.nl for Rockwell commercial GPS module info.
Those modules have an MCX/OSX antenna connector to connect a
passive ceramic patch or active GPS antenna.
They talk NMEA @ 4800,N,8,1 or Rockwell Zodiac binary @ 9600,N,8,1,
depending on jumper settings.
Rockwell Zodiac binary may be like SiRF binary as those appear
to originally have been designed as Zodiac/Jupiter replacements.
PPS accuracy is stated as 1us.

There are instructions on the web to make a dipole GPS antenna
from a length of coax cable: remove the outer insulation, trim
the outer shield and inner conductor to 46mm, and heat shrink
tubing (or tape?) to form the T shape.
You could stick that out of a gap in a window facing towards the
equator with a clear view of the sky.
-- 
Take care. Thanks, Brian Inglis