: Thursday, February 02, 2012 11:56 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Building a GPSDO trouble using Jupiter-T
This thread got started when someone asked if an analog PLL would work
for building a GSPDO. For that you do need timing pulses much faster
: Tom Van Baak
Sent: Thursday, February 02, 2012 11:56 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Building a GPSDO trouble using Jupiter-T
This thread got started when someone asked if an analog PLL would work
for building a GSPDO. For that you do need
Danielson mag...@rubidium.dyndns.org
Sender: time-nuts-boun...@febo.com
Date: Tue, 31 Jan 2012 20:50:39
To: time-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Building a GPSDO trouble using Jupiter-T
On 31/01/12 03:17
On Thu, Feb 2, 2012 at 6:42 AM, shali...@gmail.com wrote:
Magnus,
How do they compare in price to the receivers we normally use for timing?
Do you see any advantage for a timing receiver to fix faster than once per
second?
This thread got started when someone asked if an analog PLL would
Hence the need for a 100PPS from a Motorola, the 800Hz from a uBlox, the
10KHz from the Jupiter T, the 10MHz from the CW12 (the WI version, recently
developed thanks to the time-nuts list).
Anyway I still think that an analog GPSDO 1PPS based can be done. Maybe not
the best accuracy can be
Remarkably, the simplest and still one of the best GPSDO I've tested was the
10 kHz Jupiter and analog PLL-based standard by James Miller. It performed
superbly. It's the 4th GPSDO at: http://www.leapsecond.com/pages/gpsdo/
In hindsight, that doesn't seem too surprising.
I'm not a Juniper
Try this link www.serc.iisc.ernet.in/graduation-theses/babu_09.pdf
seems interesting
On Wed, Feb 1, 2012 at 1:44 AM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On 01/02/12 01:29, Chris Albertson wrote:
On Mon, Jan 30, 2012 at 6:17 PM, Didier Jugesshali...@gmail.com wrote:
You have
On Tue, 31 Jan 2012 16:29:07 -0800
Chris Albertson albertson.ch...@gmail.com wrote:
I'm pretty sure those GPS recievers that send out more frequent data,
at say 2Hz or 5Hz are just interpolating. It is not more accurate.
The GPS sats only send a frame once over 6 seconds.
As Magnus already
] Building a GPSDO trouble using Jupiter-T
On Mon, Jan 30, 2012 at 6:17 PM, Didier Juges shali...@gmail.com wrote:
You have to spend good money to get a GPS receiver capable of calculating
it's time and/or position more than once per second. I am not aware of that
being done for timing applications
On Tue, 31 Jan 2012 16:29:07 -0800
Chris Albertson albertson.ch...@gmail.com wrote:
I'm pretty sure those GPS recievers that send out more frequent data,
at say 2Hz or 5Hz are just interpolating. It is not more accurate.
The GPS sats only send a frame once over 6 seconds.
As Magnus
In your opinion, is it possible for a GPS receiver to align the PPS pulse
on multiple of the C/A code repetition rate because of (for example) badly
received satellite signals? Maybe this can happen, after the initial
acquisition, on the following updates.
On Wed, Feb 1, 2012 at 10:47 AM,
Kinali
Sent: Wednesday, February 01, 2012 4:14 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Building a GPSDO trouble using Jupiter-T
On Tue, 31 Jan 2012 16:29:07 -0800
Chris Albertson albertson.ch...@gmail.com wrote:
I'm pretty sure those GPS recievers
On 01/02/12 12:35, Azelio Boriani wrote:
In your opinion, is it possible for a GPS receiver to align the PPS pulse
on multiple of the C/A code repetition rate because of (for example) badly
received satellite signals? Maybe this can happen, after the initial
acquisition, on the following
On Wed, Feb 1, 2012 at 1:29 AM, Tom Van Baak t...@leapsecond.com wrote:
Most of the high-end GPS receivers offer faster rates than 1 Hz.
This is required for RTK work, for example. It is not interpolation.
It is hard and accurate and wonderful and expensive.
My comments were about the GPS
On 01/02/12 21:32, Chris Albertson wrote:
On Wed, Feb 1, 2012 at 1:29 AM, Tom Van Baakt...@leapsecond.com wrote:
Most of the high-end GPS receivers offer faster rates than 1 Hz.
This is required for RTK work, for example. It is not interpolation.
It is hard and accurate and wonderful and
If you do not limit yourself to NMEA you can get L1/L2 C/A and P-code and
both code and carrier phase in rates higher than 1 Hz. I have such
receivers, and you can get them as modules.
NMEA was designed for boat navagation and works well for that. I
don't need NMEA for timing. What can I
On 02/02/12 00:17, Chris Albertson wrote:
If you do not limit yourself to NMEA you can get L1/L2 C/A and P-code and
both code and carrier phase in rates higher than 1 Hz. I have such
receivers, and you can get them as modules.
NMEA was designed for boat navagation and works well for that. I
OK, will check the uBlox datasheet, until now I was assuming that the uBlox
series was capable of more than 1 fix per second in navigation and in
timing.
On Tue, Jan 31, 2012 at 3:17 AM, Didier Juges shali...@gmail.com wrote:
You have to spend good money to get a GPS receiver capable of
On Tue, 31 Jan 2012 10:26:15 +0100
Azelio Boriani azelio.bori...@screen.it wrote:
On Tue, Jan 31, 2012 at 3:17 AM, Didier Juges shali...@gmail.com wrote:
You have to spend good money to get a GPS receiver capable of calculating
it's time and/or position more than once per second. I am not
On 31/01/12 03:17, Didier Juges wrote:
You have to spend good money to get a GPS receiver capable of calculating
it's time and/or position more than once per second. I am not aware of that
being done for timing applications, but it is available for navigation GPS
receivers, such as those used to
On Mon, Jan 30, 2012 at 6:17 PM, Didier Juges shali...@gmail.com wrote:
You have to spend good money to get a GPS receiver capable of calculating
it's time and/or position more than once per second. I am not aware of that
being done for timing applications, but it is available for navigation
On 01/02/12 01:29, Chris Albertson wrote:
On Mon, Jan 30, 2012 at 6:17 PM, Didier Jugesshali...@gmail.com wrote:
You have to spend good money to get a GPS receiver capable of calculating
it's time and/or position more than once per second. I am not aware of that
being done for timing
Timing GPS receivers usually have the sawtooth correction message and I saw
an application of a delay line to correct the PPS before using it. Of
course if you time the PPSes difference with a time-to-digital you don't
need to correct the incoming hardware PPS by a delay line, but to implement
an
What about the phase jerk (details given in the datasheet) applied to
the 10KHz burst once per second?
Bruce
Azelio Boriani wrote:
Timing GPS receivers usually have the sawtooth correction message and I saw
an application of a delay line to correct the PPS before using it. Of
course if you
On Sun, 29 Jan 2012 00:50:35 -0600
Ray Xu rayxu...@gmail.com wrote:
For those who have experience using the Jupiter T GPS:
I have bought this
http://www.ebay.com/itm/Navman-jupiter-T-Tu60-GPS-Kit-1pps-10khz-GPS-Module-/260790984470
Ouch... For that price you get already a new LEA-6T, which is
Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm
a PPS-type discplining fan but I thought it was a continuous 10KHz.
On Mon, Jan 30, 2012 at 10:33 AM, Attila Kinali att...@kinali.ch wrote:
On Sun, 29 Jan 2012 00:50:35 -0600
Ray Xu rayxu...@gmail.com wrote:
For
On Mon, 30 Jan 2012 11:03:36 +0100
Azelio Boriani azelio.bori...@screen.it wrote:
Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm
a PPS-type discplining fan but I thought it was a continuous 10KHz.
No, the 10kHz signal is running continously. But the controller will
The 10kHz is continuous but its phase jerked on the second.
The new phase is held until the next jerk.
Bruce
Azelio Boriani wrote:
Ah, is it a burst of 10KHz once a second? I don't have a Jupiter-T and I'm
a PPS-type discplining fan but I thought it was a continuous 10KHz.
On Mon, Jan 30,
OK, now I know and wonder if other GPS receivers that have frequency
outputs behave in this manner. For example the Motorola 100PPS output, the
uBlox 800Hz, the Navsync variable frequency output and so on. It is
possible to compute solutions from GPS satellite at greater than 1 second
rate so the
The 100PPS output from Motorola receivers is phase jerked every second
in the same fashion.
Bruce
Azelio Boriani wrote:
OK, now I know and wonder if other GPS receivers that have frequency
outputs behave in this manner. For example the Motorola 100PPS output, the
uBlox 800Hz, the Navsync
On Mon, 30 Jan 2012 11:31:58 +0100
Azelio Boriani azelio.bori...@screen.it wrote:
OK, now I know and wonder if other GPS receivers that have frequency
outputs behave in this manner. For example the Motorola 100PPS output, the
uBlox 800Hz, the Navsync variable frequency output and so on. It is
Where can you get a LEA-6T for $ 65?
Bert Kehren
In a message dated 1/30/2012 5:34:56 A.M. Eastern Standard Time,
bruce.griffi...@xtra.co.nz writes:
The 100PPS output from Motorola receivers is phase jerked every second
in the same fashion.
Bruce
Azelio Boriani wrote:
OK, now I know
OK, so it is a common practice.
On Mon, Jan 30, 2012 at 11:43 AM, ewkeh...@aol.com wrote:
Where can you get a LEA-6T for $ 65?
Bert Kehren
In a message dated 1/30/2012 5:34:56 A.M. Eastern Standard Time,
bruce.griffi...@xtra.co.nz writes:
The 100PPS output from Motorola receivers is
On Mon, 30 Jan 2012 05:43:18 -0500 (EST)
ewkeh...@aol.com wrote:
Where can you get a LEA-6T for $ 65?
Send a mail to u-blox sales. Single pieces in the online shop are...
Well, expensive. But if you buy them from sales as engineering samples,
you get quite a lot cheaper.
Sorry, cannot give
Maybe we should consider a group buy. With all the FE 5680A purchases it
would make sense to combine them with a good GPS receiver and a digital loop.
Since there a uP's out there that have timing functions that will be a low
cost simple solution with only a few external components. A $ 2
Hi
The GPS ops signal (or 10 KHz signal) you will be trying to track will be
moving by 10's or 100's of ns per second. 10 ns per second is 10 ppb. 10 ppb at
10 GHz is 100 Hz. You need to smooth this out or your LO will be moving all
over the place.
Bob
On Jan 29, 2012, at 10:20 PM, Ray Xu
Hi
My guess is that they don't want to handle the support the LEA-6T requires on a
large scale basis. That's not to say that it's a flaky part, only that there
are a lot of cute little things in there to ask questions about …
Bob
On Jan 30, 2012, at 6:40 AM, Attila Kinali wrote:
On Mon, 30
On Sun, Jan 29, 2012 at 7:20 PM, Ray Xu rayxu...@gmail.com wrote:
Hi Chris
Thanks for your helpful input.
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did you mean that the PLL loop filter
must have a time constant of 20 minutes
On Mon, 30 Jan 2012 07:37:41 -0500 (EST)
ewkeh...@aol.com wrote:
Maybe we should consider a group buy. With all the FE 5680A purchases it
would make sense to combine them with a good GPS receiver and a digital loop.
Since there a uP's out there that have timing functions that will be a low
I take 2
Bert Kehren
In a message dated 1/30/2012 11:52:07 A.M. Eastern Standard Time,
att...@kinali.ch writes:
On Mon, 30 Jan 2012 07:37:41 -0500 (EST)
ewkeh...@aol.com wrote:
Maybe we should consider a group buy. With all the FE 5680A purchases it
would make sense to combine them
With a Rb we are talking loop time in excess of 20 minutes. Any thing other
than digital is out of reach. To day I should get my second Rb and I will
put it on aging test. The present one is better than 2 E-12 per month! I am
still hoping some one else will do an independent test. Key is
On Mon, Jan 30, 2012 at 5:16 AM, Bob Camp li...@rtty.us wrote:
Hi
The GPS ops signal (or 10 KHz signal) you will be trying to track will be
moving by 10's or 100's of ns per second. 10 ns per second is 10 ppb. 10 ppb
at 10 GHz is 100 Hz. You need to smooth this out or your LO will be
Using a $ 2 G/A (socket included) and a $ 2 PIC, four will fit on a mini
board and there are 3 boards to the order that is $ 5.17 per board. Board
is laid out, waiting for uP pin assignment and will be able to deliver in a
week board and G/A.
Bert Kehren
In a message dated 1/30/2012
On Mon, Jan 30, 2012 at 9:16 AM, ewkeh...@aol.com wrote:
With a Rb we are talking loop time in excess of 20 minutes. Any thing other
than digital is out of reach. To day I should get my second Rb and I will
put it on aging test.
My guess about why you don't see aging or so little of it is
What they do does not make any difference to us, what is important how
often we have to change the tuning word to meet our requirements, and if we
dither it will be an addition or subtraction from the center value. With out
dither it would be 4 times a month on my unit. That will allow a
So would I
Don Latham
ewkeh...@aol.com
I take 2
Bert Kehren
In a message dated 1/30/2012 11:52:07 A.M. Eastern Standard Time,
att...@kinali.ch writes:
On Mon, 30 Jan 2012 07:37:41 -0500 (EST)
ewkeh...@aol.com wrote:
Maybe we should consider a group buy. With all the FE 5680A
I would buy some. I´m in Brazil, but I can pay with Paypal...
Daniel
-
I could handle such a group buy. How many people would be interested?
The price breaks u-blox has are IIRC 1-50, 50-100,... Attila Kinali
-- Why does it take years to find the answers to the questions
Hi
Aging tends to be bidirectional ( equal probability positive or negative
within a group of Rb's ). That would make it tough to pre-estimate.
Bob
On Jan 30, 2012, at 1:40 PM, Chris Albertson albertson.ch...@gmail.com wrote:
On Mon, Jan 30, 2012 at 9:16 AM, ewkeh...@aol.com wrote:
You have to spend good money to get a GPS receiver capable of calculating
it's time and/or position more than once per second. I am not aware of that
being done for timing applications, but it is available for navigation GPS
receivers, such as those used to track race cars (for a race car, one
, but charge $5.00 handling for under $20 - 1 is $8.95, 2 is
$12.90, etc
Let me know if I can help in any way.
73,
Tom WB6UZZ
--- On Sat, 1/28/12, Ray Xu rayxu...@gmail.com wrote:
From: Ray Xu rayxu...@gmail.com
Subject: [time-nuts] Building a GPSDO trouble using Jupiter-T
To: time
:
From: Ray Xu rayxu...@gmail.com
Subject: [time-nuts] Building a GPSDO trouble using Jupiter-T
To: time-nuts@febo.com
Date: Saturday, January 28, 2012, 10:50 PM
Hi guys
I'm planning to build a GPSDO to use as a frequency ref for my GHz
ventures.
I've done research in what other people
On Sat, Jan 28, 2012 at 10:50 PM, Ray Xu rayxu...@gmail.com wrote:
Also, what is the advantage of using a OCXO instead of a VCXO in terms of
short-term accuracy? If the PLL time constant is only a few seconds, then
a crystal shouldn't deviate in frequency by too much within a few seconds,
Hi Chris
Thanks for your helpful input.
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did you mean that the PLL loop filter
must have a time constant of 20 minutes to several hours? To me, the
latter seems really unpractical for
for.
http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm
Rgds Ernie.
-Original Message-
From: Ray Xu rayxu...@gmail.com
To: time-nuts time-nuts@febo.com
Sent: Sun, Jan 29, 2012 7:51 am
Subject: [time-nuts] Building a GPSDO trouble using Jupiter-T
Hi guys
I'm
Don't confuse the PLL loop time constant with the time constant of
the analog or digital filter.
They are not the same.
Bruce
Ray Xu wrote:
Hi Chris
Thanks for your helpful input.
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did
What do you mean by average? Do you mean that the GPS and PLL must be
kept on for 20 minutes to hours, or did you mean that the PLL loop filter
must have a time constant of 20 minutes to several hours?
You have to compare the characteristics of the oscillator with the
characteristics of
The sawtooth error in the PPS output and how they were able to correct
it externally was interesting. I have seen that kind of problem
before in DDS and other applications.
I wonder what other GPS receivers provide either PPS outputs without
sawtooth noise or a correction message.
On Sun, 29
Hi guys
I'm planning to build a GPSDO to use as a frequency ref for my GHz ventures.
I've done research in what other people have built - but I have no
experience working with long-term precision/stability products (nor do I
have the equipment to do so -- I think).
I'm using the Jupiter T (the
: [time-nuts] Building a GPSDO trouble using Jupiter-T
Hi guys
I'm planning to build a GPSDO to use as a frequency ref for my GHz ventures.
I've done research in what other people have built - but I have no
xperience working with long-term precision/stability products (nor do I
ave the equipment to do
:
From: Ray Xu rayxu...@gmail.com
Subject: [time-nuts] Building a GPSDO trouble using Jupiter-T
To: time-nuts@febo.com
Date: Saturday, January 28, 2012, 10:50 PM
Hi guys
I'm planning to build a GPSDO to use as a frequency ref for my GHz ventures.
I've done research in what other people have built
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