Lady Heather - Learning Holdover - Page 1
Forum section: electronics / testgear

author: BUR
author_rank: Newbie
timestamp: July 05, 2019, 09:10:04 am
content: I'm running Lady Heather 6.14 B on Windows 10 64bit without any problem.The GPSDO is a BG7TBL with Oscillioquarz inside (Star4)I don’t know what the indication "Learning Holdover" in Yellow means.Will this message turn in sometime (weeks) to green od it's just an information what the GPSDO is doing?Any help would be appreciated.Rolf

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: July 05, 2019, 12:52:49 pm
content: I'm no time nut butthis articledoes explain what holdover is and why it's necessary.I am guessing that Lady Heather 'remembers' when the time was most accurate and can learn and use that information to influence the OCXO when there are fewer satellites or the angle of view is restricted.

author: BUR
author_rank: Newbie
timestamp: July 05, 2019, 01:20:59 pm
content: Thank you. I'm aware of what holdover is for, but i don’t know what the message on the display of Lady Heather means.Finally, I let it go for several days how knows. perhaps in some days we will see a green message...Rolf

author: jpb
author_rank: Super Contributor
timestamp: July 05, 2019, 04:59:48 pm
content: I have two Oscilloquartz Star 4+ GPSDOs, they start off with yellow "Learning holdover" when first powered on and then transition to "holdover perf good" in green when they have learned sufficient information.It takes a while and it is different from the position hold mode transition (where it has learned the co-ordinates and can go into timing mode proper). It seems to take several days for my setup and one transitioned quicker than the other even though both were turned on at the same time.They are basically learning the value of parameters to model changes with temperature and drift so that they can continue to make adjustments if the GPS signal is lost. For the average amateur user it doesn't matter much as the GPS signal is almost never lost and if it was the frequency reference is probably not critical. It matters much more for telecoms providers who have to meet particular standards for holdover.

author: BUR
author_rank: Newbie
timestamp: July 05, 2019, 05:06:14 pm
content: PerfectThank you, I will be patient enoughRolf

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: July 06, 2019, 12:58:25 am
content: So does my GPSDO run differently when I don't have Lady Heather connected or is the stuff I see in the LH display just a presenattion of what the GPSDO is doing? I ask because I leave the GPSDO plugged in by the PC gets powered down most of the time.

author: texaspyro
author_rank: Super Contributor
timestamp: July 06, 2019, 03:25:45 am
content: Quote from: Gandalf_Sr on July 06, 2019, 12:58:25 amHeather just reports what the GPSDO is sending. The only time it affects the GPSDO is when you change a device setting.Also I think the holdover learning time is 24 hours...

author: Electro Fan
author_rank: Super Contributor
timestamp: July 06, 2019, 04:39:25 am
content: Quote from: BUR on July 05, 2019, 09:10:04 amWhat model (date?) BG7TBL do you have? Are you sure it has an Oscilloquartz and is a Star4? Thx

author: BUR
author_rank: Newbie
timestamp: July 06, 2019, 05:10:35 am
content: I'm 100% certain that I have a STAR4 inside. Outside no date but just engraved what should be inside. Opening the Box, we can see the star4 Board and the 8663-XSRolf

author: jpb
author_rank: Super Contributor
timestamp: July 06, 2019, 09:22:32 am
content: Quote from: BUR on July 06, 2019, 05:10:35 amI think if it is Star4+ then this is a GPSDO in its own right so is not a BG7TBL which is a different controller that sometimes has Oscilloquartz 8664 OCXOs in.Mine are Star4 GPSDOs and not BG7TBL.Does yours say BG7TBL on the outside?

author: BUR
author_rank: Newbie
timestamp: July 06, 2019, 09:49:47 am
content: ok Mine is a BG7TBL with a OEM Board inside

author: BUR
author_rank: Newbie
timestamp: July 17, 2019, 04:00:46 pm
content: After some days it turned to a ok green message