Re: [time-nuts] Antique precision timing device without electronics

This is mine, used to calibrate some aircraft related equipment: https://www.flickr.com/photos/103726899@N08/33326340242/in/dateposted-public/ and its diagram: https://www.flickr.com/photos/103726899@N08/33482556075/in/dateposted-public/ iov >Messaggio originale >Da: "Mike Seguin"

Re: [time-nuts] Smart Phone time display accuracy...?

> Not to gloat, but my Android phone is always spot on. I have a GPS time > app that shows the difference between GPS and phone time and it's always in > the tenths of a second area. "tenths of a second" is "spot on"? No way. That is a difference that is perceivable to humans. Apple claims

Re: [time-nuts] Vectron 233Y5317 OCXO data 250 Mhz

Thank you gentlemen! 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Bob Raker Sent: Thursday, March 16, 2017 6:48 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Vectron 233Y5317 OCXO data 250 Mhz Jeff, You have a

Re: [time-nuts] Smart Phone time display accuracy...?

kb...@n1k.org said: > Under normal conditions, the Gold Codes on CDMA are synchronized to < 100 > ns. Is that a full time synchronization, or something like a PPS where they can get the ticks lined up but not know the time for any individual tick? -- These are my opinions. I hate spam.

Re: [time-nuts] Smart Phone time display accuracy...?

There is a NTP app for the iPhone called Gorgy Atomic Timing Clock. You can choose from about 6 different NTP servers and it has an audible tick. It does not (can not) set the iPhone's clock. https://itunes.apple.com/us/app/atomic-clock-gorgy-timing/id295302256?mt=8 It was free, but now is

Re: [time-nuts] Smart Phone time display accuracy...?

On Thu, Mar 16, 2017 at 2:32 PM, Severin Haas wrote: > The German PTB has a nice widget (https://uhr.ptb.de) to see the actual > time + deviation ("Abweichung"). Can not test this from another location > than UTC+1h, but probably it works at your location. > Does anybody of

Re: [time-nuts] Vectron 233Y5317 OCXO data 250 Mhz

Jeff, You have a 250MHz VCXO +/100 ppm deviation for +/-5V 12V supply Here are general specs: https://www.vectron.com/products/vcxo/co-233vf_233vfw.htm 73, BR On Thu, Mar 16, 2017 at 4:51 PM, Jeff AC0C wrote: > Looking for a datasheet for this OCXO, or for the

Re: [time-nuts] Vectron 233Y5317 OCXO data 250 Mhz

Hi Not an OCXO, but it’s a Vectron 233 https://www.vectron.com/products/xo/co-233_233h.htm The 233’s are all un-compensated XO’s Bob > On Mar 16, 2017, at 4:51 PM, Jeff AC0C wrote: > > Looking for a datasheet for this OCXO, or for the general family. > > Thanks!

Re: [time-nuts] Smart Phone time display accuracy...?

There is a lot of...problematic...advice here. For instance: Gary Woods wrote on Thu, 16 Mar 2017 at 18:09:26 -0400 in : > Not to gloat, but my Android phone is always spot on. I have a GPS > time app that shows the

Re: [time-nuts] Smart Phone time display accuracy...?

Hi Under normal conditions, the Gold Codes on CDMA are synchronized to < 100 ns. It’s only when something goes wrong that they drift out to the 10 us range. Once they get there, the transmitter needs to shut down. Unfortunately, there is no mandatory connection between the transmitter time

Re: [time-nuts] Smart Phone time display accuracy...?

>From occasional observations of my IPhone 5 using the emerald sequoia emerald >time application the "within 50 milliseconds" claim seems quite reasonable to >me. Mark Spencer > On Mar 16, 2017, at 12:31 PM, Chris Albertson > wrote: > > Apple Support claims

Re: [time-nuts] Smart Phone time display accuracy...?

On Thu, 16 Mar 2017 13:16:11 -0700, you wrote: >My iPhone seems to be accurate to 5 minutes or so. There are two of them in >my >house and they never agree. My computer is saying 1:15 PM local time, my >iPhone >says 1:20PM Not to gloat, but my Android phone is always spot on. I have a GPS

Re: [time-nuts] Antique precision timing device without electronics

I think Bob Pease of National Semiconductor fame mentioned looking for the earliest use of phase locked loops and finding a reference to a European clock maker who had a master pendulum clock with a mechanical coupling that phase locked newly built clocks when left connected overnight. On Thu, 16

Re: [time-nuts] Antique precision timing device without electronics

Very interesting use of a tuning fork. I have only seen this once before. I have the tuning fork used with an Ampex Model 300 reel to reel tape machine. The tuning fork was used as a reference in the power supply that drove the capstan motor for accurate speed. It's 60 Hz not 25 Hz. It's

[time-nuts] Vectron 233Y5317 OCXO data 250 Mhz

Looking for a datasheet for this OCXO, or for the general family. Thanks! 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] Smart Phone time display accuracy...?

On Thu, Mar 16, 2017 at 3:31 PM, Chris Albertson wrote: > Again it would be fun to measure. There is an API call to get the > system time. One could write a simple app to send this out > The iOS "Time" app/NTP client has been mentioned here before. It displays the

Re: [time-nuts] Smart Phone time display accuracy...?

The German PTB has a nice widget (https://uhr.ptb.de) to see the actual time + deviation ("Abweichung"). Can not test this from another location than UTC+1h, but probably it works at your location. Does anybody of you know how they are measuring the time deviation? Some JavaScript Voodoo? Am

Re: [time-nuts] Smart Phone time display accuracy...?

My iPhone seems to be accurate to 5 minutes or so. There are two of them in my house and they never agree. My computer is saying 1:15 PM local time, my iPhone says 1:20PM On 3/15/2017 7:32 PM, Mike Baker wrote: Hello, Time-nutters-- Any thoughts on what the likely accuracy of smart phone

Re: [time-nuts] Smart Phone time display accuracy...?

There are GPS apps for phones such as GPS Test Plus for Android that display the time as received from the phone's GPS. I'm not sure if phones' GPS modules produce a PPS output, but it would be cool if an app could send a tick to the phone's speaker/headphones on the second. > > Le 16 mars 2017

[time-nuts] Antique precision timing device without electronics

Very cool! Thanks for sharing. You could probably use any of the large vintage neon bulbs to replace the missing lamp. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] Antique precision timing device without electronics

For the bulb you can probably replace it with a W1A or AR-1bulb which is an argon bulb commonly used in old school contact printers they have a purple hue and also emit long wave UV light I doubt if they are still manufactured but a photo shop or studio or chemist shop which developed film

[time-nuts] Shout Out to N8UR in QST

Congratulations on the nice article about John in the April issue of QST. 73, N4TVC, Randy "..I set out to discover the inventions of God." - John Muir ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] Antique precision timing device without electronics

Hi Morris, If there's no active devices (and you'd be sure to see them, not solid state) where does the power to operate the motor come from? Is it the same contacts that drive the fork? It's amazing that there is high Q when contacts must be operated by the fork. Did it come with instructions

Re: [time-nuts] Smart Phone time display accuracy...?

Apple Support claims "within 50 milliseconds of the definitive global time standard". At least that is what Apple gives in their spec. It might use difference source depending on which radios are enabled. The phone does have GPS and a cell network radio and both can be used for time.But on a

Re: [time-nuts] Smart Phone time display accuracy...?

The time on mine is quite good, but I believe that’s because I have an Apple watch. If you pair an iOS device to an Apple Watch, I believe it suddenly “tries much harder” to keep its own clock in sync so that it can serve good time sync to the watch. Apple has made grandiose claims about the

Re: [time-nuts] Smart Phone time display accuracy...?

Mine is a little over a second slow. Good enough for a date but not for any sort of nut. > Le 16 mars 2017 à 03:32, Mike Baker a écrit : > > Hello, Time-nutters-- > > Any thoughts on what the likely accuracy of smart phone time > displays might be? I am thinking that

Re: [time-nuts] Smart Phone time display accuracy...?

It COULD be very good. It would be easy for them to run NTP inside the phone. But I don't think they do as battery life is "everything" I think on IOS they periodically run SNTP. I just as interesting question is how to measure the phone's display? The biggest problem with all visual

Re: [time-nuts] Smart Phone time display accuracy...?

CDMA mobile telephony needs system synchronization to +/- 10 uS in order to smoothly handoff a moving client from one cell to the next. Most systems use GPS to maintain this 10 uS. This says nothing about how bad it could get after that. Mike -Original Message- From: time-nuts

[time-nuts] Antique precision timing device without electronics

Hi all, I was recently asked to resurrect this interesting device by a colleague who collects antique scientific instruments. It’s a "Chronoscope" made by the H. Tinsley company in London in the early 20th century and used to measure time intervals with the precision of those days. It's large

[time-nuts] Smart Phone time display accuracy...?

Hello, Time-nutters-- Any thoughts on what the likely accuracy of smart phone time displays might be? I am thinking that the stacking of delays along the path to its receive antenna plus any internal processing delays would accumulate to some unknown degree. Any thoughts on this? Mike Baker

Re: [time-nuts] WTB: GPSDO

On Wed, Mar 15, 2017 at 1:09 AM, Attila Kinali wrote: > IMHO it's much easier to just > get a known-good GPSDO and a rubidium for verification. Yes, for sure it is easiest to buy something that already works. But the question was how to bootstrap from scratch? In other words,