[time-nuts] Z3801A version issues - was Re: Substitute GPS in a Z3801A
paulswedb at gmail.com
Mon Aug 30 01:23:05 UTC 2010
I seem to remember a rollover about then that obsoleted older gps units.
On Sun, Aug 29, 2010 at 5:40 PM, Matthew Kaufman <matthew at matthew.at> wrote:
> I believe I've found a difference between the faulty units and the working
> units... The faulty ones come up as 1/1/1997 when you do :SYSTEM:PRESET, the
> good ones come up as 1/1/1998. Does this difference ring any bells for
> Matthew Kaufman
> On 6/24/2010 8:41 AM, Matthew Kaufman wrote:
>> I now have *two* Z3801A units which misbehave in the following way (which
>> this thread reminded me of):
>> The GPS status says it acquires quite a few (5-6) satellites with high
>> signal strength... then after a minute or two, for no apparent reason, it
>> loses *all* of them simultaneously but immediately goes back into
>> "acquiring" for the ones it was seeing, and a few seconds later, they're all
>> back. During this time, survey (if in progress) is halted and then restarts
>> and runs for a bit before halting again when it loses everything briefly
>> again. Then, within days, the unit ends up out of lock... if I go check it,
>> I see it doing the same thing, and when the satellites are being received it
>> is in "fine frequency adjust" mode, but so far off the 1pps phase that it
>> really has no hope of re-locking before the next time it drops and then
>> reacquires all the satellites.
>> This is independent of antenna, location, and 48v power source... one unit
>> apparently has been this way since I got it, the other worked fine for
>> months and then developed this problem.
>> Without knowing more, I'm thinking it might simply be a bad GPS receiver
>> board, thus the idea of trying to find a replacement, perhaps one that is
>> better at staying acquired, has crossed my mind.
>> Matthew Kaufman
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