The new Garmin Etrex series has GPS and Glonass. /Björn
Hello,
Wednesday, October 19, 2011, 1:21:31, Tom Van Baak wrote:
T So the antenna and receiver architecture is more complicated. Have you
seen any
T portable car navigation or cell phones with GLONASS?
Smartphone with both nav
Warren,
This will be fun. Are these standard TBolts or ones with external
oscillator (Rb)?
I won't address the issue of noise measurement in this email.
The first question is how long did you collect data among the sites?
The standard GPS Common View that the timing labs do is based
on 13
Le 19/10/2011 07:03, Yuri Ostry a écrit :
Hello,
Wednesday, October 19, 2011, 1:21:31, Tom Van Baak wrote:
T So the antenna and receiver architecture is more complicated. Have you seen
any
T portable car navigation or cell phones with GLONASS?
Smartphone with both nav systems (sorry,
Actually no, it doesn't have to be the software. In my day job, I work
for a company that makes terminal servers (networked serial
concentrators) and have seen many times where USB/serial converters do
not behave properly. I would bet that choosing a different USB/serial
dongle would fix the
Tim,
you may EZGPIB give a try, download from
http://www.ulrich-bangert.de/html/downloads.html
Regards
Ulrich
-Ursprungliche Nachricht-
Von: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Tim Tuck
Gesendet: Dienstag, 18. Oktober 2011 13:36
An:
Thanks Guys, Gives me lots to consider and go over.
Not going to be quite as easy as I hoped. Then if it was easy it would not
be Nut-fun.
Lots to learn, which I do best with experiments.
Sounds like using times much longer than 1 Hr is the way others do it, But
then they have different
Ed
I think I have confused things by doing two completely different things.
One is how best to make a better Tbolt GPSDO,
the other is how use a Tbolt to make a remote OSC tester.
To do the first, the osc needs to be disciplined slowly,
to do the second, best to do it using the disable mode
David,
I'm in a similar position to you regarding GPS aerials, may I ask where
you obtained your 'better puck'?
John H.
John,
I'm currently trying this unit from londoncolour:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItemitem=250687616146
and it produces a consistently higher total
Hello,
Wednesday, October 19, 2011, 10:04:06, Mike Cook wrote:
m and on the bay of course. see for example 150659387614, again a Russian
m product which even flags the sats with the national flag. Navigation
m only, but a nut might want to poke probes into it.
Russian design based on one of
BTW, Looks like iPhone 4s is also GLONASS-capable.
http://9to5mac.com/2011/10/19/apple-appeases-russians-and-improves-gps-with-glonass-support/
--
Björn
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Hi Tom,
I am very eager to see lab reports of low-cost combined
GPS+GLONASS receivers. I bet Said has good info on
the u-blox 4T vs. 5T vs. 6T but now that he's selling to us
instead of sharing with us, you've noticed how quiet he
is about all this.
Sorry, haven't posted as much info as
El 19/10/2011 19:51, b...@lysator.liu.se escribió:
BTW, Looks like iPhone 4s is also GLONASS-capable.
http://9to5mac.com/2011/10/19/apple-appeases-russians-and-improves-gps-with-glonass-support/
And it seems to incorporate a nice multifunction IC
I have two thunderbolts, set up so that I can switch over to the backup unit if
the primary fails.
All is well with that, but what could I do to detect a less obvious failure,
like 9.99 MHz output?
If they disagree, I don't know how to resolve which is correct.
The thunderbolts produce status information and error estimates about how
they are doing. If you are willing to trust that, you can remove the one
that is falling out of tolerance. If you aren't willing to trust that, then
I'm pretty sure you'll need a third frequency standard to compare each
I have two thunderbolts, set up so that I can switch over to the backup unit
if the primary fails. All is well with that, but what could I do to detect a
less obvious failure, like 9.99 MHz output?
If they disagree, I don't know how to resolve which is correct.
Get a 3rd. 2 good guys
As Hal says and as in instrument flying, three independent sources of data
before reaching a conclusion. If one disagrees, throw it out.
A third source is in order. A third TBolt, an LPRO-101 adjusted to and
compared regularly to each TBolt, or another GPSDO of another flavor. Also,
a CS unit
On Wed, Oct 19, 2011 at 12:46 PM, David VanHorn
d.vanh...@elec-solutions.com wrote:
I have two thunderbolts, set up so that I can switch over to the backup
unit if the primary fails.
All is well with that, but what could I do to detect a less obvious
failure, like 9.99 MHz output?
If
Simple way is to use LadyHeather.
From its output, you can tell if either or both are working correctly as
well as how well they are working.
That is assuming of course that there is at least one working GPS satellite
in view at all times.
If not it well tell you that also.
ws
Hi, gang,
Did we just have another GPS epoch rollover? My trusty old Odetics 425
seems to believe the date is March 4th, 1992.
I could probably correct it in firmware, if I looked hard and long
enough, but the ToD is still correct and the frequency standard is
staying nicely
Not for another eight years or so
Connected by DROID on Verizon Wireless
-Original message-
From: Bruce Lane kyr...@bluefeathertech.com
To: time-nuts@febo.com
Sent: Wed, Oct 19, 2011 21:19:01 GMT+00:00
Subject: [time-nuts] Epoch rollover?
Hi, gang,
Did we just have another
The last rollover was in August 1999, just before Y2K, and the next
rollover will be in April 2019.
From: Bruce Lane kyr...@bluefeathertech.com
This is the famous man who has two watches does not know what time it is
problem.
Lucent solved it for telecom with the RFTGm (Reference Frequency and Timing
Generator) equipment, consisting of GPS disciplined OXO and Rubidium
oscillator modules that continuously checked each other via 1 PPS and
signature database 6558 (20111019) __
The message was checked by ESET Smart Security.
http://www.eset.com
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Out of curiosity, what would be the consequences of a steadily increasing
phase error? Would it offend your sense of perfection or would it have real
consequences?
Phase error wouldn't bug me. My worst fear is that the 10.00 MHz standard
might be 10.02 MHz.
I need to implement
On 10/19/2011 11:18 PM, Bruce Lane wrote:
Hi, gang,
Did we just have another GPS epoch rollover? My trusty old Odetics 425
seems to believe the date is March 4th, 1992.
Units can have their internal shifted rollovers. This is well
illustrated using a GPS date calculator:
On 10/20/2011 12:18 AM, David VanHorn wrote:
Out of curiosity, what would be the consequences of a steadily increasing
phase error? Would it offend your sense of perfection or would it have real
consequences?
Phase error wouldn't bug me. My worst fear is that the 10.00 MHz standard
Steadily increasing phase error is to let there be a frequency error.
Frequency is the derivate of phase, so it comes with the territory.
So a 200 ns per second phase drift would provide a frequency error of 2
Hz on your 10 MHz. Can't have one without the other.
I understand, I'm just saying
On 19 Oct, 2011, at 14:18 , Bruce Lane wrote:
Did we just have another GPS epoch rollover? My trusty old Odetics 425
seems to believe the date is March 4th, 1992.
I could probably correct it in firmware, if I looked hard and long
enough, but the ToD is still correct and the
On 10/20/2011 12:57 AM, David VanHorn wrote:
Steadily increasing phase error is to let there be a frequency error.
Frequency is the derivate of phase, so it comes with the territory.
So a 200 ns per second phase drift would provide a frequency error of 2
Hz on your 10 MHz. Can't have one
Seems to me that 200 ns is 720 degrees of phase error, which is a lot.
A person handy with logic circuits could build a simple phase detector
with a flip-flop and an RC filter with a tenth second time constant.
An analog circuit could detect 360 degree rollover and set off alarm
bells. Note that
I believe that the Thunderbolt firmware would catch such a thing.There is
quite a bit of error checking and TRAIM (time receiver autonomous integrity
monitoring) done.
If the osc was off in freq, the firmware would try to use the EFC voltage to
slew it back into agreement with the GPS
I do assume this is because of the 1024 week cycle? if so would it be
possible to tell the GPS what cycle it should be?
Would the 10MHz out still be accurate?
BR. Thomas.
2011/10/20 Mark Sims hol...@hotmail.com:
On July 30, 2017 all our Thunderbolts turn into back-dated pumpkins...
Maybe this is too simple
LadyHeather is always checking the Tbolt's Internal Osc value against the
GPS.
By watching it's plot outputs you can tell if the Tbolt is on freq.
(compared to the GPS)
If no plot outputs, then something is broken, at that point is does not
matter what, can assume it
Can anyone tell me the transmission frequencies used for GPS?
Wikipedia says 1.57542 GHz (L1 signal) and 1.2276 GHz (L2 signal), but
I'm confused about what the L2 signal is. Is this only of use to the
military since the data is encrypted, or can consumer based GPS
systems use this frequency?
My
Hi David:
Here's a table listing all of them I know about and their harmonic numbers.
http://www.prc68.com/I/DAGR.shtml#GPSs
also see
http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by_GPS
The signals are all circular polarization, but the handedness would be
difficult to describe.
On Wed, Oct 19, 2011 at 6:25 PM, David Kirkby david.kir...@onetel.net wrote:
My reason for wanting to know is so I can design an antenna for GPS,
Are you trying to build something you can't buy or is this just to see
if you can. The timing antana you can buy on eBay use a helix
antenna in a
My reason for wanting to know is so I can design an antenna for GPS, but it
wont be used for military purposes, so I've no idea whether I need to worry
about the performance at the lower frequency or not.
Look at the specs for your receiver. If it doesn't use L2 there is no reason
for the
On 20 October 2011 03:10, Hal Murray hmur...@megapathdsl.net wrote:
My reason for wanting to know is so I can design an antenna for GPS, but it
wont be used for military purposes, so I've no idea whether I need to worry
about the performance at the lower frequency or not.
Look at the specs
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