[time-nuts] Substitute GPS in a Z3801A

Matthew Kaufman matthew at matthew.at
Thu Jun 24 14:00:49 EDT 2010


40 miles, from a high level comm site to/from my house at a very RF- 
quiet elevated location. Interference is very unlikely.

Matthew Kaufman

(Sent from my iPhone)

On Jun 24, 2010, at 9:08 AM, "Robert Benward" <rbenward at verizon.net>  
wrote:

> When you say you changed location, are we speaking of moving the  
> antenna to the other side of the roof, or across town?  Sounds  
> suspciously like interference.
>
> Bob
>
>
> ----- Original Message ----- From: "Matthew Kaufman" <matthew at matthew.at 
> >
> To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com 
> >
> Sent: Thursday, June 24, 2010 11:41 AM
> Subject: Re: [time-nuts] Substitute GPS in a Z3801A
>
>
>> 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
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
> --- 
> --- 
> --- 
> --- 
> --------------------------------------------------------------------
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.829 / Virus Database: 271.1.1/2960 - Release Date:  
> 06/24/10 02:35:00
>




More information about the time-nuts mailing list