My 9390 and Z3801 always shows the same time. - Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Miles Sent: Sunday, November 25, 2007 7:35 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Cell Phone time ? I doubt it's possible to make any general statements about the accuracy of the time display on a phone. It updates whenever the firmware gets the proverbial round-tuit time slice. My old phone, a Motorola flip-phone variant of some kind, was always dead-on versus the Thunderbolt on Qwest's Seattle-area CDMA network. But it had nothing to do but sit there and mark time. My current phone is an iPhone on the AT&T GSM/EDGE network, and it seems to lag about 7 seconds behind UTC as reported by the Datum 9390. That puts it 21 seconds behind GPS time as reported by the Thunderbolt. It doesn't appear to make a difference whether it's connected or not. -- john, KE5FX > Well, this may seem like a dumb question to some of you, but, it does have > me baffled a little. I have noticed some time ago that the time > indicated on > my cell phone is usually two to four seconds ahead of GPS time. I > was under > the impressions that most towers did use GPS time. Anyway, I > wrote it off to > thinking that the phone is free running unless connected to a > call and hence > the drift. I even tried this theory by dialing my cell phone from my land > line, and low and behold, the times matched with GPS as long as I was > connected. Soon as I disconnected it was immediately off 4 seconds and > eventually settled at about 2 seconds. Since there is a signal > indicator on > the cell phone that is active all of the time, it is obviously receiving > something from a local tower. Could that signal not have GPS time embedded > in it? It must have some, since going from one time zone to the other > switches the cell phone time automatically, but obviously not > accurately. It > seems like a 2 second window is pretty large to search to make > all of those > bits line up so one can talk, or to even have the phone ring. > Thanks for any > help in making me understand this small dilemma. Regards - Mike > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
