Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-10-20 Thread Jim Lux
On 8/21/12 9:53 AM, Sarah White wrote: Wow. Okay. The user manual actual considers this cable delay to be worth mention? I can see why the trimble thunderbolt is a favorite among time nuts <3 I'm sold. Cable time offset is in basically all GPSes. An awful lot of GPS receivers (for timing)

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-21 Thread Hal Murray
kuze...@gmail.com said: > ... I would presume that the fixed location used for above calculations > would be relative to the position of the antenna? A side effect of figuring out where you are is figuring out when you are there. There are 4 unknowns: X, Y, Z, T, so you need 4 equations. You g

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-21 Thread Sarah White
Wow. Okay. The user manual actual considers this cable delay to be worth mention? I can see why the trimble thunderbolt is a favorite among time nuts <3 I'm sold. On 8/21/2012 12:48 PM, Chris Albertson wrote: > On Tue, Aug 21, 2012 at 9:35 AM, Sarah White wrote: > >> Thanks Chris. >> >> I alwa

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-21 Thread Chris Albertson
On Tue, Aug 21, 2012 at 9:35 AM, Sarah White wrote: > Thanks Chris. > > I always appreciate clear explanations. I'm assuming that the "fixed > location" requirement is important to note for purposes of compensating > for any dopler shift, as well as the distance the signal must first > travel bef

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-21 Thread Michael Tharp
On 08/21/2012 12:35 PM, Sarah White wrote: Thanks Chris. I always appreciate clear explanations. I'm assuming that the "fixed location" requirement is important to note for purposes of compensating for any dopler shift, as well as the distance the signal must first travel before being decoded.

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-21 Thread Sarah White
Thanks Chris. I always appreciate clear explanations. I'm assuming that the "fixed location" requirement is important to note for purposes of compensating for any dopler shift, as well as the distance the signal must first travel before being decoded. ... I would presume that the fixed location u

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-20 Thread Chris Albertson
On Mon, Aug 20, 2012 at 3:10 PM, Sarah White wrote: > > I really like that the thunderbolt can (assuming the initial location > has been uploaded, or the default "site survey" has been completed) > still keep accurate time / discipline based on a single satellite lock > (before falling back on th

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-20 Thread Michael Blazer
Just order one from RJB1998 (http://www.ebay.com/itm/120969870669?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649) Friday and it's here today. $169 with free shipping. He included a power cable (6 pin to leads) and a TNC-F cable. Mike Blazer On 8/20/2012 4:07 PM, cfo wrote: On Sun, 19 Aug

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-20 Thread Hal Murray
kuze...@gmail.com said: > ... Is that a common feature? Know of any good ones other than the trible > thunderbolt? It's standard in GPSDOs. It requires special firmware in the GPS unit. -- These are my opinions. I hate spam. ___ time-nuts mail

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-20 Thread Sarah White
CFO: oooh, really. So 10mhz reference is pretty standard for a GPS disciplined frequency standard. Thanks. I really like that the thunderbolt can (assuming the initial location has been uploaded, or the default "site survey" has been completed) still keep accurate time / discipline based on a si

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-20 Thread cfo
On Sun, 19 Aug 2012 15:29:22 -0400, Sarah White wrote: > oh wow, thanks. I'll try that. > > Also, I figured out that typing in "trimble thunderbolt" instead of > "thunderbolt gps" gives me zero hits for phone... but fewer hits for the > GPSDO too :( > Try to search on : 10mhz gps You should s

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Didier Juges
Another option is a "low end" laptop. I use a Dell D400 laptop, with a 1.8GHz Pentium M and it draws about 20W from A/C with the display blanked, which is the way an NTP server will be most of the time. The power brick rating assumes running the laptop AND charging the battery at the same time

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Sarah White
RS232 port (Stan, W1LE) >3. Re: L1 GPS timing signal(s) into local time on computer(s) > (KD0GLS) >4. Embedded NTP servers? (Michael Tharp) >5. Re: Modern motherboard with RS232 port (Chris Albertson) > > > ------------------------

Re: [time-nuts] : L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Willy Willemse
ed NTP servers? (Michael Tharp) 5. Re: Modern motherboard with RS232 port (Chris Albertson) -- Message: 1 Date: Sun, 19 Aug 2012 10:41:39 -0400 From: Sarah White To: time-nuts@febo.com Subject: Re: [time-nuts] L1 GPS timing signal(

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Chris Albertson
On Sat, Aug 18, 2012 at 10:23 PM, wrote: > If you are using a desktop, I'd suggest putting in a serial card. The > Netmos chip based cards work on windows and linux, though your should do an > internet search on the particular card before you buy. > > I have the prolific based converter. It didn'

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread KD0GLS
In my experience (which is admittedly less than that of many others here) the time reported is that of the PPS pulse that just happened, and the documentation usually bears that out. There's a real-time clock running inside the receiver that is synchronized to the PPS. At the top of the second,

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Sarah White
Ken: >From what I've read, most GPS modules which output PPS, the NMEA sentence has the timestamp of the next, upcoming pulse. Regardless of how the NMEA or other time data is, the PPS itself is only a guarantee "this is the boundary for a second" and NTP documentation typically recommends a secon

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Bill Dailey
The time when the names sentence was sent is the time in the sentence.. The pps signals every second..they are independent. Tat is the very nature of the problem with the nmea sentence..latency associated with the message itself. Sent from my iPad On Aug 19, 2012, at 6:11 AM, Ken Duffill wrot

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Ken Duffill
Just one further question. When the pps input triggers, so my linux box knows a second has just ticked; is the time of that second the one the NMEA sentence has just sent, or will send next? Or to put it another way, when I receive an NMEA sentence is this the current time (as was when the s

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-19 Thread Bill Dailey
I will jump in a bit. I, and many have been right where you are. You are correct...USB is a no go for accurate time. Same on windows. So you need a Linux box with serial port. Anything from a Beaglebone, pandabox...or pc will work. You certainly need a gps with a pulse per second output (m

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-18 Thread Hal Murray
kuze...@gmail.com said: > this is a no-name cheapo SIRF module > 1) I need a computer with a serial port. The curent GPS module I'm using is > INTERNALLY RS232 --> USB converter, and recognized by my windows 7 computer > as: "Prolific USB-to-Serial Comm Port (COM3)" ... the latency and jitter is

Re: [time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-18 Thread lists
sion of precise time and frequency measurement Subject: [time-nuts] L1 GPS timing signal(s) into local time on computer(s) Hi, this is my first post. First off. Windows 7 USB connection to the GPS (no serial ports / modern computer) and I'm pretty sure that is my main problem. Past f

[time-nuts] L1 GPS timing signal(s) into local time on computer(s)

2012-08-18 Thread Sarah White
Hi, this is my first post. First off. Windows 7 USB connection to the GPS (no serial ports / modern computer) and I'm pretty sure that is my main problem. Past few months, I've been trying to figure out my timing issues. Lots of reading & trying to figure out how to best configure everything. I'm