Re: [time-nuts] more of a time distribution question

Hal Murray wrote on Thu, 30 Mar 2017 at 13:43:34 -0700 in <20170330204334.18a8d406...@ip-64-139-1-69.sjc.megapath.net>: > That should work too. I don't know much about the Mac environment. If it's > running a normal-enough ntpd it is already a server and you don't

Re: [time-nuts] TAPR TICC boxed

A single or dual supply CMOS output comparator should suffice together with some diode clamps. Since the TICC only resolves a few tens of picosec the choice of comparator etc isnt critical. LTC6752 (~$US2) or similar perhaps? A single supply comparator should suffice unless you want to

Re: [time-nuts] GPS first LO need to be locked?

> > BTW a lot of GPS receivers don't have a "first LO".. they are more like a >> Tuned RF receiver - an input BPF for L1, L2, or L5, then direct sampling at >> around 30-40 MHz - something that makes the GPS signals alias down >> somewhere convenient (and always have positive frequency offset

[time-nuts] TAPR TICC boxed

What did you do for input protection? I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or

Re: [time-nuts] GPS first LO need to be locked?

Thanks everyone for your comments. It will be a GPSDP TBolt or Z3801 reference. I just wanted to eliminate some variables at this stage. Regards Paul WB8TSL On Thu, Mar 30, 2017 at 7:56 PM, Bob kb8tq wrote: > Hi > > > > On Mar 30, 2017, at 7:05 PM, jimlux

Re: [time-nuts] GPS first LO need to be locked?

Hi > On Mar 30, 2017, at 7:05 PM, jimlux wrote: > > On 3/30/17 10:32 AM, Bob Camp wrote: >> Hi >> >> There is a limited tracking range for Doppler. You would need to stay inside >> that. >> > > Doppler is pretty big when the spacecraft is coming or going at the

Re: [time-nuts] more of a time distribution question

On 3/30/17 1:11 PM, Majdi S. Abbas wrote: On Thu, Mar 30, 2017 at 09:37:50AM -0700, jimlux wrote: Running NTP (in some flavor) would be the obvious approach, but I'm in an environment where there's no "outside" connectivity.. Could I make one of the beaglebones be the NTP server, and the others

Re: [time-nuts] GPS first LO need to be locked?

On 3/30/17 11:06 AM, Peter Monta wrote: I am curious if the first local oscillator on a GPS receiver must actually be locked or coherent to the reference oscillator in the GPS receiver typically running at some 10 MHz approximately. Or as long as the first LO is quite stable it doesn't matter

Re: [time-nuts] GPS first LO need to be locked?

On 3/30/17 10:32 AM, Bob Camp wrote: Hi There is a limited tracking range for Doppler. You would need to stay inside that. Doppler is pretty big when the spacecraft is coming or going at the horizon, about 5 kHz (out of 1.5 GHz, so 4-5 ppm). Relatively speaking, GPS satellites are moving

Re: [time-nuts] more of a time distribution question

jim...@earthlink.net said: > I've got a bunch (a pack?) of beaglebones that are connected via ethernet > (wired) and I want them to be (roughly) synchronized. How rough? > Running NTP (in some flavor) would be the obvious approach, but I'm in an > environment where there's no "outside"

Re: [time-nuts] more of a time distribution question

https://www.eecis.udel.edu/~mills/ntp/html/orphan.html On Thu, Mar 30, 2017 at 12:37 PM, jimlux wrote: > > Pointers to documentation would be appreciated. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] more of a time distribution question

On Thu, Mar 30, 2017 at 09:37:50AM -0700, jimlux wrote: > Running NTP (in some flavor) would be the obvious approach, but I'm in an > environment where there's no "outside" connectivity.. Could I make one of > the beaglebones be the NTP server, and the others be the clients? Disciplining

Re: [time-nuts] more of a time distribution question

On Thu, 30 Mar 2017 09:37:50 -0700 jimlux wrote: > Running NTP (in some flavor) would be the obvious approach, but I'm in > an environment where there's no "outside" connectivity.. Could I make > one of the beaglebones be the NTP server, and the others be the clients?

[time-nuts] HP5061B Ion Current

https://www.febo.com/pipermail/time-nuts/2017-March/104374.html I posted another HP cesium beam tube patent at http://gonascent.com/papers/hp/hp5061/US3387130.pdf . It covers the formation of the cesium beam and should be of interest. We now have over a month of operation on our first HP5061B

[time-nuts] more of a time distribution question

I've got a bunch (a pack?) of beaglebones that are connected via ethernet (wired) and I want them to be (roughly) synchronized. Running NTP (in some flavor) would be the obvious approach, but I'm in an environment where there's no "outside" connectivity.. Could I make one of the beaglebones

Re: [time-nuts] GPS first LO need to be locked?

Hi There is a limited tracking range for Doppler. You would need to stay inside that. Bob Sent from my iPhone > On Mar 30, 2017, at 9:46 AM, paul swed wrote: > > I am curious if the first local oscillator on a GPS receiver must actually > be locked or coherent to the

Re: [time-nuts] GPS first LO need to be locked?

> I am curious if the first local oscillator on a GPS receiver must actually > be locked or coherent to the reference oscillator in the GPS receiver > typically running at some 10 MHz approximately. Or as long as the first LO > is quite stable it doesn't matter because the receiver can track the

Re: [time-nuts] TAPR Oncore M12+ kit

Bob, Couldn't find a part number on the .jpg of the gps rx to to cross reference. Have a few +T's. Don't need another timing rx. Would take a few positioning rx's as the M12+ units are good for balloon launches. Reads out >65535ft. See top comment. Norm n3ykf On Thu, Mar 30, 2017 at 7:33 AM,

[time-nuts] GPS first LO need to be locked?

I am curious if the first local oscillator on a GPS receiver must actually be locked or coherent to the reference oscillator in the GPS receiver typically running at some 10 MHz approximately. Or as long as the first LO is quite stable it doesn't matter because the receiver can track the code.

Re: [time-nuts] TAPR Oncore M12+ kit

Hi At least from a quick read of the TAPR page it’s not real clear if the GPS modules are M12+T or just M12+ boards. I believe that if they don’t have the T on the end, they don’t have sawtooth / PPS (?). Bob > On Mar 30, 2017, at 2:11 AM, Mike Cook wrote: > > I would

Re: [time-nuts] HP5061B Cesium Oven Properties

Donald some great work you are doing and since many of us have 5061s that are on fumes this is a great way to further extend the life while operating. The run time may be different for various ovens. If its 83c then it was a high flux tube. They burned up the Cs at a fasterate to give a better

Re: [time-nuts] TAPR Oncore M12+ kit

I would like to add mention of the M12+ interface board that Tom Wimmenhove offered on this list. I am using them to lock PRS10s. Very happy with it. Here is a link to some of his performance measurements. < http://tomwimmenhove.com/otherstuff/Oncore/ > > Le 28 mars 2017 à 20:47, Gregory Beat