[time-nuts] Z3801A with other GPS receiver

Jason Rabel jason at extremeoverclocking.com
Fri May 18 17:37:25 EDT 2007


For the price people are paying on eBay, it seems almost easier to sell a
Z3801 and but a Fury... lol.

But then that would defeat the whole challenge of a DIY project. ;)

Back on topic - From what I remember reading, I thought the sawtooth bug was
in earlier firmware versions. What about the newer firmwares that supposedly
have that fixed (or was it never fixed)?


>I seem to remember that one or more of the HP boxes that used the 6/8
channel 
>Motorola GPS receivers used a secret method of making use of the sawtooth
error 
>information.  Some trick was needed because there was a bug that caused the

>sawtooth to be wrong every now and then and it always was wrong in the same

>polarity.  Therefore you could not average using the sawtooth.  Most 
>applications just ignored the sawtooth output and averaged.
>
>But if the Z3801 is using the sawtooth, and you replace the receiver with 
>another model, then there will be a problem.  A fix would be if someone
would 
>come clean and tell us how HP got around the sawtooth bug in detail, then
you 
>could take the output from an M12+T and recreate a data stream that would
look 
>just like the 6/8 channel unit including the buggy sawtooth byte.
>
>Have Fun,
>Brooke Clarke




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