Re: HP 10811-60111 info
Talbot Andrew <actalbot@...>
All GPS modules you can buy off-the-shelf have a 1 PPS output. If you are using that to lock a good OXCO then expect a lock up time of a few minutes to several hours depending on how you want to trade off the PLL parameters, trading instantaneous frequency accuracy against lockup. I believe the CT1 design allows you to customise the loop parameters as you want.
GPS receivers themselves give a short term timing variation of a few parts in 10^-9 over tens of seconds to minutes so for microwaves, at least above 5.7GHz, its nice to smooth this out otherwise you'll end up with a tone that wanders just about audibly. A
THe Motorola Oncore in many of its variants (M12, GT, UT) is one of the easier to drive modules, as is the Garmin Family (GPS25, 35). The Jupiter-T has a 10kHz output which makes frequency locking a lot simpler, but it not such a nice board to drive if you are interresteed in the data from it.
Take a look at the presentation I gave to the HFC a few weeks ago on using GPS.
It can be found at: www.frars.org.uk