So your AC/DC?. Very modern. I am using a Rubidium which ir great but I have also bought A GPS receiver that is supposed to be good for a making a GPS disciplined clock. Never got it to work though.
Very bad video and wrong explanations. You confuse Allan stability with drift and accuracy, (12:00 -14:05) and really do not understand, how the Holdover technique of the TrueTime receiver works (40:05 - 46:00). The receiver simply 'forgot' all of its learnt OCXO drift (over t, T) parameters, the nominal DAC setting, and all phase drift and offset information. Maybe it also forgot its position information, which is necessary for correct operation. All this takes a few days to recover on such precise GPS devices, so that can't be compared to the performance of this simple Chinese GPS receiver. At 20:00 - 21:00 , the 2e-9 jitter origins from the GPS signal, not from the OCXO , which is typically 1E-12. Please get Allan Deviation diagrams for GPS receivers and for OCXO so that you understand this correctly.
> The receiver simply 'forgot' all of its learnt OCXO drift (over t, T) parameters ... Maybe. I'm not familiar with the TrueTime but in similar devices learnt tempco behaviour is retained not forgotten. Of the two, ageing is the characteristic that has to be dumped and re-learnt.
I wonder if this unit will suffer the April 6th, 2019 1024 week Decade Rollover Bug.
What does the viewing angle knob do? Does it tilt the display?
Shabbymannen It alters the bias on the LCD display so the contrast is optimum for a given viewing angle. Never seen it before as an external control.
Thanks Martin, I really enjoy the timekeeping subject.
Can use the Model XL-DC as a NTP with ethernet to set your computer clock ? tjl
So your AC/DC?. Very modern. I am using a Rubidium which ir great but I have also bought A GPS receiver that is supposed to be good for a making a GPS disciplined clock. Never got it to work though.
You should also look at the ublox devices. Same accuracy but under $10.
Would be nice, if we can use this GPS monster as NTP server :) no?
You did your homework and the video was very well done. Thanks!
Somewhere near Gibraltar
Great Video !
That's interesting. Thanks Martin.
GREAT, really great shot! Thank You vy 73 de DL1LEP
I am a big fan of unreasonable accuracy.
That's almost as many zeroes as on my bank account! ;)
Manuauto just like my... but without anything else bfore it :) just the zeros hehehhe
N35 degrees and W08 and 791 meters high? I think I can find you if I wanted to. Great video guy but tell us how to apply this to our ham radios.
Useful video
Very bad video and wrong explanations.
You confuse Allan stability with drift and accuracy, (12:00 -14:05) and really do not understand, how the Holdover technique of the TrueTime receiver works (40:05 - 46:00). The receiver simply 'forgot' all of its learnt OCXO drift (over t, T) parameters, the nominal DAC setting, and all phase drift and offset information. Maybe it also forgot its position information, which is necessary for correct operation. All this takes a few days to recover on such precise GPS devices, so that can't be compared to the performance of this simple Chinese GPS receiver.
At 20:00 - 21:00 , the 2e-9 jitter origins from the GPS signal, not from the OCXO , which is typically 1E-12. Please get Allan Deviation diagrams for GPS receivers and for OCXO so that you understand this correctly.
> The receiver simply 'forgot' all of its learnt OCXO drift (over t, T) parameters ...
Maybe. I'm not familiar with the TrueTime but in similar devices learnt tempco behaviour is retained not forgotten. Of the two, ageing is the characteristic that has to be dumped and re-learnt.
does not ship to Germany :-( Trump, s bloc commercial?
My seiko wristwatch is more enjoyable than this. Yes time is not %100 correct and thats the beauty of it :)
Out of depth and struggling? Keep going.