[Lowfer] GPS frequency lock

[John Davis]

>
>Does anyone here know much about PLLs?  I'm trying to figure out how to
lock
>my DDS beacon to the 1pps output from a GPS (all in software) and I can't
see
>a good way to do it.  1pps is awfully slow(or too fast, depends on how you
>look at it) and my clock is very coarse (500KHz).
>
>Anyone want to take this off list and give me some pointers?  I just can't
>see a clean way to do the lock.


Unfortunately, the site in Portugal seems to have a bad link to the PDF that
supposedly tells how to lock to the 1pps signal, though the 10 MHz article
is there.

There was an article in either QST or QEX a couple of years back that shows
a method for doing the sort of thing you seek, but it's a bit complex.
There's a PDF of that article floating around, which I don't find at
present, but I'm sure someone still has a copy they could send to you.  It
doesn't accomodate a 500kHz clock directly, but it would point you in the
right direction.

John