Author Topic: Lars DIY GPSDO with Arduino and 1ns resolution TIC  (Read 34669 times)

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Offline Miti

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Re: Lars DIY GPSDO with Arduino and 1ns resolution TIC
« Reply #275 on: September 20, 2019, 11:33:18 am »
Hi,

I'm having some troubles with my Lars GPSDO. After more than 7 months (or so) when it stayed locked, it started loosing lock every few days. I caught some events that seem to be satellite related, unless the OCXO shifts phase all of a sudden. Please take a look. What do you think?
First I thought is power loss but it is connected to a UPS and it didn't loose a PPS for almost 9 months.
That big spark at power up was by design!
 

Online imo

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Re: Lars DIY GPSDO with Arduino and 1ns resolution TIC
« Reply #276 on: September 20, 2019, 05:16:36 pm »
External GPS antenna is dying?
 

Offline Miti

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Re: Lars DIY GPSDO with Arduino and 1ns resolution TIC
« Reply #277 on: September 23, 2019, 02:10:02 am »
External GPS antenna is dying?

I don't have an external antenna, it is at the window. It didn't give me any troubles for 7 months.
That big spark at power up was by design!
 

Offline metrologist

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Re: Lars DIY GPSDO with Arduino and 1ns resolution TIC
« Reply #278 on: September 23, 2019, 03:51:19 pm »
It looks like you briefly lost gps lock, then are settled back into lock 12 hours later with a dac value ~30 points higher. How much does your dac vary in a day? I would plot dac variances over a long period to look for a trend.
 


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