[time-nuts] Z3801A recovering

[Art Sepin]

Joe,

In a way, the VP Service Note: http://www.synergy-gps.com/images/stories/ShopTalk/vp_service_note.pdf ties into the VP Oncore Startup Note because it is associated with the VP Oncore's Pendulum oscillator.

Back in the late nineties, some customers noted that VP Oncore signal strength diminished over time when operating 24/7/365. Motorola determined that the decreased sensitivity was caused by crystal aging which is normally corrected every time the VP is power-cycled. Power-cycling lets the VP write the appropriate, aged, oscillator characteristics to EEPROM to reset the VP to its expected performance range. If you note signal strengths being reduced over time, then it would be wise to power-cycle your VP -  Otherwise, just let it run.

Art



-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Joseph Gray
Sent: Tuesday, April 26, 2016 2:14 PM
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Subject: Re: [time-nuts] Z3801A recovering

Art,

Thanks for the link. Very useful information. I also read the 'VP Service note" posted there. Is that note also referring to the oscillator, or some other component that needs periodic recalibration.
In any case, it seems that they are recommending that we power down our GPSDO units every few months. Not something I'd like to do, considering it would take a while to stabilize again.

Joe Gray
W5JG


On Tue, Apr 26, 2016 at 12:39 PM, Art Sepin <art at synergy-gps.com> wrote:
> Joe,
>
> There is a "VP Oncore Startup" note here that's worth a try:
>
> https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fwww.sy
> nergy-gps.com%2findex.php%3foption%3dcom_content%26task%3dview%26id%3d
> 42%26Itemid%3d89&data=01%7c01%7cart%40synergy-gps.com%7c1cb76a2494c44f
> 59344908d36e1e9356%7cc81f9fdec0e04d8c95779afaa0cad9ed%7c1&sdata=voZraL
> rW%2bW827wV3qF8HsbZaRda09LAvawpb3DCk4wg%3d
>
> Please note that if the above link expands to more than one line after it leaves our server it is due to our use of MS SafeLinks app in Outlook. If the link is not active, just go to:
> Synergy-gps.com\Tech Support\ Shop Talk and scroll down to the start-up note.
>
> Art Sepin
>
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