Bob, Thanks for that. I am going to dig! Joe
On Tue, Nov 10, 2020 at 7:56 PM Bob kb8tq <[email protected]> wrote: > Hi > > If you are handling the sawtooth correctly, you should see no hanging > bridges > at all. My guess is that the spikes are coming from a problem in the > sawtooth > correction “stuff”. With no correction, you *will* see a spike as is rolls > over. With > a correction error, you would also see a spike. > > Bob > > > On Nov 10, 2020, at 11:37 AM, Joe & Gisela Noci <[email protected]> > wrote: > > > > Hi Bob, > > Yes, I am - I use a Dallus digital delay line in series with the GPS 1pps > > and program the delay line each second with the GPS delay estimate in the > > GPS NAV message. > > It works really well, jitter on the 1pps pulse is hugely reduced, but one > > side effect is that those 'hanging bridges' can become severely extended > in > > time. > > I can by pushbutton selection bypass the delay line, ie, no sawtooth > > correction - since I do not have a reference frequency source, I cannot > say > > if it is better or worse. > > However, the logged values output from the time-digital convertor still > > shows the spikes either way- I still suspect the spikes are conversion > > artifacts from digital noise in the box.. > > Being green on the science of this I packed to much 'stuff' into the > > enclosure and there are DC-DC converters for power, Nucleo processor > > running at 140MHz, a NEXTION touch screen LCD, which > > I am discovering is very noisy, etc....It is difficult to target any > > solution at the moment as I believe there are too many areas that are > > marginal - I need to clean it up! > > Joe > > > > On Tue, Nov 10, 2020 at 6:24 PM Bob kb8tq <[email protected]> wrote: > > > >> Hi > >> > >> Are you using sawtooth correction? > >> > >> Bob > >> > >>> On Nov 10, 2020, at 8:55 AM, Joe & Gisela Noci <[email protected]> > wrote: > >>> > >>> Hi everyone, > >>> Still playing with my GPSDO..The Rubidium source I was hoping to have > the > >>> loan off did not work out, so still in the dark. I have sort of > convinced > >>> myself to procure a reasonable 'proven' source, Rubidium or whatever, > but > >>> that > >>> seems to be more easily decided than done..Or at least so if the money > >>> available is not astronomical... Also complicated by the difficulties > >>> getting the goods here to Namibia! > >>> > >>> Anyway, I am still unhappy with my analogue time-to-digital conversion > - > >> I > >>> do see the odd spike in the logged data and have been unable to find > why > >> - > >>> have applied lots of filtering of supplies, used a separate A/D > >> convertor ( > >>> as opposed to the convertor internal to the STM Processor) with own dc > >>> regulated supply, own clean A/D Reference voltage ( 1ppm device). > etc... > >>> > >>> Does not mean implementing a digital method will get rid of the spikes, > >> so > >>> I am still chasing that till I understand, but to that end: > >>> I found this device and am keen to get the dev kit and try it out : > >>> > >> > https://www.sciosense.com/products/time-to-digital-converters/development-kit-for-as6500/ > >>> > >>> Has anyone perhaps played with it? Would be interested to know more > about > >>> it if so.. > >>> Regards > >>> Joe > >>> V51JN / ZS6JGN > >>> > >>> On Wed, Oct 28, 2020 at 7:08 PM Alberto di Bene <[email protected]> > wrote: > >>> > >>>> On 2020-10-28 2:29, jimlux wrote: > >>>>> I'm still agitating for alien deviation - Microsoft offers it as a > >>>>> suggestion, but not Allan, so it must be true. > >>>> > >>>> :-):-):-) > >>>> > >>>> Thanks Tom and Jim for the explanations. All clear now. > >>>> > >>>> 73 Alberto I2PHD > >>>> > >>>> > >>>> > >>>> _______________________________________________ > >>>> time-nuts mailing list -- [email protected] > >>>> To unsubscribe, go to > >>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >>>> and follow the instructions there. > >>>> > >>> _______________________________________________ > >>> time-nuts mailing list -- [email protected] > >>> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >>> and follow the instructions there. > >> > >> > >> _______________________________________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > >> > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
