Re: [time-nuts] Long period variation of GPS PPS timing?

[Jean-Louis Oneto]

Hi,
If your GPS run in fixed position mode, how do you determine the position? 
Could this cycle be an artefact caused by a bad position? 50 mn could be the 
order magnitude of visibility of a satellite?

Just a thought...
HTH,
Regards,
Jean-Louis Oneto
- Original Message - 
From: "David C. Partridge" 
To: "'Discussion of precise time and frequency measurement'" 


Sent: Thursday, July 01, 2010 8:38 PM
Subject: Re: [time-nuts] Long period variation of GPS PPS timing?


Sawtooth variation in pps time - that does sound a bit familiar in 
reference to GPS timing.


e.g.:   but that's over 
a MUCH shorter time scale than you report which seems to a around 3000 
seconds.


So I wouldn't write it off as being unrelated to the GPS quite yet, but I 
admit I can't think of an obvious candidate with this sort of period.


Regards,
David Partridge


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
Behalf Of Paul Nicholson

Sent: 01 July 2010 19:44
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Long period variation of GPS PPS timing?

FYI, some time has elapsed with one soundcard instead of two and the slow 
cycle is still present, same period, and the phase of the slow cycle did 
not make a step change.


Now I must take a careful look at how the centroid is being determined, 
the resampling, RC temperature, etc.
Maybe the 'sawtoothness' of the cycle should be telling me something.  If 
nothing jumps out at me, I'll change the rise/fall time constants of the 
RC network and see if that alters the slow cycle.

--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] Info on MTI osc.

[Luis Cupido]

Tks, Bruce,
Tks, John,

Looks that is it.

(I could not find the info...
must improve my googling skils hi).

Not sure how to decipher the reference but
at least I know it is a 5MHz and know
what kind of performance to expect, in principle.

Many thanks.

Luis Cupido.
ct1dmk.


John Miles wrote:

Looks like the 230 series is still supported by Milliren:
http://www.mti-milliren.com/pdfs/230.pdf

-- john, KE5FX


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on
Behalf Of Luis Cupido
Sent: Thursday, July 01, 2010 4:20 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Info on MTI osc.


Does anyone has data on the
MTI 230-0546-A  OCXO (5MHz).

( If no datasheet, just pinout best guess
may help ).

Many thanks.

Luis Cupido.
ct1dmk.




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Re: [time-nuts] Info on MTI osc.

[John Miles]

Looks like the 230 series is still supported by Milliren:
http://www.mti-milliren.com/pdfs/230.pdf

-- john, KE5FX

> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on
> Behalf Of Luis Cupido
> Sent: Thursday, July 01, 2010 4:20 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] Info on MTI osc.
> 
> 
> Does anyone has data on the
> MTI 230-0546-A  OCXO (5MHz).
> 
> ( If no datasheet, just pinout best guess
> may help ).
> 
> Many thanks.
> 
> Luis Cupido.
> ct1dmk.
> 


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Re: [time-nuts] Info on MTI osc.

[Bruce Griffiths]

Luis Cupido wrote:
MTI 230-0546-A 

Is the pinout similar to the other 230 series OCXOs?:
http://www.mti-milliren.com/pdfs/230.pdf

Bruce


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[time-nuts] Info on MTI osc.

[Luis Cupido]

Does anyone has data on the
MTI 230-0546-A  OCXO (5MHz).

( If no datasheet, just pinout best guess
may help ).

Many thanks.

Luis Cupido.
ct1dmk.


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[time-nuts] GPSDO article

[EWKehren]

There is an interesting article describing the Quartzlock E8000 series of  
GPSDO's in the June 2010 Microwave Journal. It goes into details as to 
method  used. Worth reading.
Bert Kehren
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Re: [time-nuts] Long period variation of GPS PPS timing?

[David C. Partridge]

Sawtooth variation in pps time - that does sound a bit familiar in reference to 
GPS timing.

e.g.:   but that's over a 
MUCH shorter time scale than you report which seems to a around 3000 seconds.

So I wouldn't write it off as being unrelated to the GPS quite yet, but I admit 
I can't think of an obvious candidate with this sort of period.

Regards,
David Partridge


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of Paul Nicholson
Sent: 01 July 2010 19:44
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Long period variation of GPS PPS timing?

FYI, some time has elapsed with one soundcard instead of two and the slow cycle 
is still present, same period, and the phase of the slow cycle did not make a 
step change.

Now I must take a careful look at how the centroid is being determined, the 
resampling, RC temperature, etc.
Maybe the 'sawtoothness' of the cycle should be telling me something.  If 
nothing jumps out at me, I'll change the rise/fall time constants of the RC 
network and see if that alters the slow cycle.
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Joseph M Gwinn]

time-nuts-boun...@febo.com wrote on 07/01/2010 02:01:25 PM:

> From:
> 
> Paul Nicholson 
> 
> To:
> 
> Discussion of precise time and frequency measurement 

> 
> Date:
> 
> 07/01/2010 02:02 PM
> 
> Subject:
> 
> Re: [time-nuts] Long period variation of GPS PPS timing?
> 
> Sent by:
> 
> time-nuts-boun...@febo.com
> 
[snip]
> 
> Joe Gwinn wrote:
>  > The centroid of pulses triggered by the leading edge of the
>  > 1PPS pulse will vary with the width of the pulses.
> 
> I see.  It is a passive network but unprotected from temperature
> changes.  It is shut in a box with 2 PCs and a bunch of other
> stuff.  Various fans on and off. Temperature varies 26-30C in
> the box.   I need to look at temperature, but gut feeling tells
> me the cycle is a little too regular and is some subtle software
> defect, aliasing or something.   I must plot soundcard drift
> rate against the slow cycle, etc.   I can tackle this with
> confidence now that I know it is not a GPS limitation.  Thanks
> for that.

If the room temperature varies (due to the cycling of the heating system), 
the temperatures within the box will vary more or less in parallel. 

PC power dissipation varies with computational load, so periodic 
processing can cause periodic temperature variation.

The quickest way to tell is to log temperature while logging PPS timing, 
and see if they correlate.  The temperature measurement need not be all 
that accurate, so long as the sensor is stable and has good resolution.

Joe Gwinn

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Re: [time-nuts] PICTIC II PCB group buy

[John Green]

Add me to the list.
Thanks
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Re: [time-nuts] Long period variation of GPS PPS timing?

[Paul Nicholson]

FYI, some time has elapsed with one soundcard instead
of two and the slow cycle is still present, same period,
and the phase of the slow cycle did not make a step
change.

Now I must take a careful look at how the centroid is
being determined, the resampling, RC temperature, etc.
Maybe the 'sawtoothness' of the cycle should be telling
me something.  If nothing jumps out at me, I'll change
the rise/fall time constants of the RC network and see
if that alters the slow cycle.
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Paul Nicholson]

Matthew Kaufman wrote:
> What is the soundcard sample rate? This feels like an artifact
> of sample phase vs. pulse phase to me.

There are actually two soundcards, running at

 192003.8285 and
 192002.1638

samples/sec, varying a little.  They are on different computers.
One takes an East/West signal, the other a North/South signal.
Each is timed and resampled to 192000.0 based on the PPS supplied
to both soundcards.  The two timestamped data streams are then
brought together for bearing and phase extraction.

The plotted phase is actually the mean (weighted by signal
strength) of the phases separately determined for each signal.

Tests with a signal generator show that the signals are being
correctly resampled, only a small and fairly constant phase
error between the two signals.

Perhaps there is some subtle aliasing between the two signals
and/or soundcards. I have altered things now to only look at the
signal from one antenna, one soundcard.  Will know in an hour
or so if this has made a difference to the slow cycle.

Joe Gwinn wrote:
> The centroid of pulses triggered by the leading edge of the
> 1PPS pulse will vary with the width of the pulses.

I see.  It is a passive network but unprotected from temperature
changes.  It is shut in a box with 2 PCs and a bunch of other
stuff.  Various fans on and off. Temperature varies 26-30C in
the box.   I need to look at temperature, but gut feeling tells
me the cycle is a little too regular and is some subtle software
defect, aliasing or something.   I must plot soundcard drift
rate against the slow cycle, etc.   I can tackle this with
confidence now that I know it is not a GPS limitation.  Thanks
for that.
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] Pictic II PCB group buy board cost $8

[Jim Robbins]

Hi Stan,

I'm also interested in the PICTIC II group buy.  Many thanks.

Jim Robbins
N1JR
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[time-nuts] Pictic II PCB group buy board cost $8

[Stanley Reynolds]

I expect the board cost to be $8 each + shipping.

Will email everyone I receive a request from in a few days and then post here 
for any lost emails / last call.

Stanley

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Joseph M Gwinn]

time-nuts-boun...@febo.com wrote on 07/01/2010 12:06:54 PM:

> From:
> 
> Paul Nicholson 
> 
> To:
> 
> Discussion of precise time and frequency measurement 

> 
> Date:
> 
> 07/01/2010 12:08 PM
> 
> Subject:
> 
> Re: [time-nuts] Long period variation of GPS PPS timing?
> 
> Sent by:
> 
> time-nuts-boun...@febo.com
> 
> Thanks all for the various replies, on and off list.
> 
> John WA4WDL wrote:
>  > Perhaps you should use only the leading edges for the
>  > pulse-to-pulse interval measurement.
> 
> Yes, I'm just using the leading edge, turning it into a pulse
> using a couple of RC networks, slowing the rise and fall enough
> to give a nice shape for accurate locating of the centroid.

The centroid of pulses triggered by the leading edge of the 1PPS pulse 
will vary with the width of the pulses.  If you are using a non-precision 
pulse generator, many things can affect the apparent locations of the 1PPS 
pulses.  Like changes in temperature and/or supply voltage.

Joe Gwinn

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Matthew Kaufman]

What is the soundcard sample rate? This feels like an artifact of  
sample phase vs. pulse phase to me.


Matthew Kaufman

(Sent from my iPhone)

On Jul 1, 2010, at 9:06 AM, Paul Nicholson  wrote:


Thanks all for the various replies, on and off list.

John WA4WDL wrote:
> Perhaps you should use only the leading edges for the
> pulse-to-pulse interval measurement.

Yes, I'm just using the leading edge, turning it into a pulse
using a couple of RC networks, slowing the rise and fall enough
to give a nice shape for accurate locating of the centroid.

Antonio CT1TE wrote:
> I can send you the yesterday record of my GPS TBolt #2 against
> DCF77, which apparently doesn't show any periodic phase
> variation.

Thanks for the offer.  Hold on that, I'll assume for now that
this slow cycle is not ionospheric.

Rob Kimberley wrote:
> I'm assuming your location is fixed, and you are tracking
> sufficient SVs,

Fixed.  Maybe I can relocate the GPS antenna for a better view of
the sky.

Peter Vince wrote:
> I don't believe that cyclic variability is GPS - I've not
> noticed such a thing on any of the systems I monitor.

Thanks, that's very helpful.  Knowing that this is not normal
behaviour for GPS timing means that I can set about tracking down
a system fault.

There are a few things I can think of to check.  The cycle must
correlate with something - soundcard rate, temperature, CPU clock,
etc.  It is pretty consistent, here is a bit more of MSF 60kHz
and also DCF at 77.5kHz,

http://abelian.org/vlf/live/pp100701msfc.png
http://abelian.org/vlf/live/pp100701dcfc.png

Thanks again, I'll report back when I find the problem.
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] Long period variation of GPS PPS timing?

[J. Forster]

Is the environment heated or have AC? With a period of about 40 minutes
I'd look for something thermal.

FWIW,

-John




> Hi
>
> What kind of caps are you using in the network? Some of the stuff you get
> these days has really awful TC.
>
> I'd put a heat gun on your R/C networks and see what happens...
>
> Bob
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
> Behalf Of Paul Nicholson
> Sent: Thursday, July 01, 2010 12:07 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Long period variation of GPS PPS timing?
>
> Thanks all for the various replies, on and off list.
>
> John WA4WDL wrote:
>  > Perhaps you should use only the leading edges for the
>  > pulse-to-pulse interval measurement.
>
> Yes, I'm just using the leading edge, turning it into a pulse
> using a couple of RC networks, slowing the rise and fall enough
> to give a nice shape for accurate locating of the centroid.
>
> Antonio CT1TE wrote:
>  > I can send you the yesterday record of my GPS TBolt #2 against
>  > DCF77, which apparently doesn't show any periodic phase
>  > variation.
>
> Thanks for the offer.  Hold on that, I'll assume for now that
> this slow cycle is not ionospheric.
>
> Rob Kimberley wrote:
>  > I'm assuming your location is fixed, and you are tracking
>  > sufficient SVs,
>
> Fixed.  Maybe I can relocate the GPS antenna for a better view of
> the sky.
>
> Peter Vince wrote:
>  > I don't believe that cyclic variability is GPS - I've not
>  > noticed such a thing on any of the systems I monitor.
>
> Thanks, that's very helpful.  Knowing that this is not normal
> behaviour for GPS timing means that I can set about tracking down
> a system fault.
>
> There are a few things I can think of to check.  The cycle must
> correlate with something - soundcard rate, temperature, CPU clock,
> etc.  It is pretty consistent, here is a bit more of MSF 60kHz
> and also DCF at 77.5kHz,
>
>   http://abelian.org/vlf/live/pp100701msfc.png
>   http://abelian.org/vlf/live/pp100701dcfc.png
>
> Thanks again, I'll report back when I find the problem.
> --
> Paul Nicholson
> http://abelian.org
> --
>
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>
>
>
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Re: [time-nuts] Long period variation of GPS PPS timing?

[Paul Nicholson]

Bob Camp wrote:
> I'd put a heat gun on your R/C networks and see what happens...

Yes, good point.  The RCs must have a temperature coefficient,
maybe not something I can neglect, I'd better look at that.

In fact, now that I know it's not inherent to GPS, I have quite
a long list of things to eliminate.

Will get busy... thanks again.
--
Paul Nicholson
http://abelian.org/
--



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Re: [time-nuts] PICTIC II PCB group buy

[EWKehren]

Stanly
 I have shipped in the last couple of month boards to NZ and Germany.  No 
problem, but you have to make sure for Europe no lead, is an option with  
Expr. PCB, may want to include a copy of the invoice that clearly shows no 
lead.  An old cut up padded envelop in a regular envelop with customs 
declaration does  the trick. Italy may still be a problem. The reason I use a 
regular 
envelope on  the outside I do not want it look comercial.
Bert
 
 
In a message dated 7/1/2010 12:13:29 P.M. Eastern Daylight Time,  
stanley_reyno...@yahoo.com writes:

Am  01.07.2010 16:44, schrieb Stanley Reynolds:

> OK, email me off list  the number of boards and address so I can 
calculate 
> postage and I  will order them.

The price would be at my cost and actual shipping, no  packaging or 
processing 
charges added by me. Not sure of price till I have  the number of boards 
but hope 

as a group we will get a better price.  This would also allow us to order 
just 1 
if that is the need. I can take  papal but that has their cost as well. I 
would 
not expect money till I've  received the boards and I'm ready to ship. 

ebay fee 2.9% + $0.30 USD,  outside USA 3.9% + $0.30 USD  + currency 
conversion 
fee ( not shown  on papal site with my first look for it )

I will ship to any country  for which it is possible from the post office. 
If a 
lot of paper work is  required for your country then guess we need a 
export/import broker as  this is my first experience with  this.

Stanley

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[time-nuts] PICTIC II PCB group buy

[Stanley Reynolds]

Am 01.07.2010 16:44, schrieb Stanley Reynolds:

> OK, email me off list the number of boards and address so I can calculate 
> postage and I will order them.

The price would be at my cost and actual shipping, no packaging or processing 
charges added by me. Not sure of price till I have the number of boards but 
hope 

as a group we will get a better price. This would also allow us to order just 1 
if that is the need. I can take papal but that has their cost as well. I would 
not expect money till I've received the boards and I'm ready to ship. 

ebay fee 2.9% + $0.30 USD, outside USA 3.9% + $0.30 USD  + currency conversion 
fee ( not shown on papal site with my first look for it )

I will ship to any country for which it is possible from the post office. If a 
lot of paper work is required for your country then guess we need a 
export/import broker as this is my first experience with this.

Stanley

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Bob Camp]

Hi

What kind of caps are you using in the network? Some of the stuff you get
these days has really awful TC. 

I'd put a heat gun on your R/C networks and see what happens...

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Paul Nicholson
Sent: Thursday, July 01, 2010 12:07 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Long period variation of GPS PPS timing?

Thanks all for the various replies, on and off list.

John WA4WDL wrote:
 > Perhaps you should use only the leading edges for the
 > pulse-to-pulse interval measurement.

Yes, I'm just using the leading edge, turning it into a pulse
using a couple of RC networks, slowing the rise and fall enough
to give a nice shape for accurate locating of the centroid.

Antonio CT1TE wrote:
 > I can send you the yesterday record of my GPS TBolt #2 against
 > DCF77, which apparently doesn't show any periodic phase
 > variation.

Thanks for the offer.  Hold on that, I'll assume for now that
this slow cycle is not ionospheric.

Rob Kimberley wrote:
 > I'm assuming your location is fixed, and you are tracking
 > sufficient SVs,

Fixed.  Maybe I can relocate the GPS antenna for a better view of
the sky.

Peter Vince wrote:
 > I don't believe that cyclic variability is GPS - I've not
 > noticed such a thing on any of the systems I monitor.

Thanks, that's very helpful.  Knowing that this is not normal
behaviour for GPS timing means that I can set about tracking down
a system fault.

There are a few things I can think of to check.  The cycle must
correlate with something - soundcard rate, temperature, CPU clock,
etc.  It is pretty consistent, here is a bit more of MSF 60kHz
and also DCF at 77.5kHz,

  http://abelian.org/vlf/live/pp100701msfc.png
  http://abelian.org/vlf/live/pp100701dcfc.png

Thanks again, I'll report back when I find the problem.
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Paul Nicholson]

Thanks all for the various replies, on and off list.

John WA4WDL wrote:
> Perhaps you should use only the leading edges for the
> pulse-to-pulse interval measurement.

Yes, I'm just using the leading edge, turning it into a pulse
using a couple of RC networks, slowing the rise and fall enough
to give a nice shape for accurate locating of the centroid.

Antonio CT1TE wrote:
> I can send you the yesterday record of my GPS TBolt #2 against
> DCF77, which apparently doesn't show any periodic phase
> variation.

Thanks for the offer.  Hold on that, I'll assume for now that
this slow cycle is not ionospheric.

Rob Kimberley wrote:
> I'm assuming your location is fixed, and you are tracking
> sufficient SVs,

Fixed.  Maybe I can relocate the GPS antenna for a better view of
the sky.

Peter Vince wrote:
> I don't believe that cyclic variability is GPS - I've not
> noticed such a thing on any of the systems I monitor.

Thanks, that's very helpful.  Knowing that this is not normal
behaviour for GPS timing means that I can set about tracking down
a system fault.

There are a few things I can think of to check.  The cycle must
correlate with something - soundcard rate, temperature, CPU clock,
etc.  It is pretty consistent, here is a bit more of MSF 60kHz
and also DCF at 77.5kHz,

 http://abelian.org/vlf/live/pp100701msfc.png
 http://abelian.org/vlf/live/pp100701dcfc.png

Thanks again, I'll report back when I find the problem.
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] PICTIC II

[Reeves Paul]

And here is a request for yet another, to keep the price down :-)

regards,
paulg8gja

-Original Message-
From: Stanley Reynolds [mailto:stanley_reyno...@yahoo.com]
Sent: 01 July 2010 16:42
To: time-nuts@febo.com
Subject: Re: [time-nuts] PICTIC II


The price would be at my cost and actual shipping, no packaging or
processing 
charges added by me. Not sure of price till I have the number of boards but
hope 
as a group we will get a better price. This would also allow us to order
just 1 
if that is the need. I can take paypal but that has their cost as well. I
would 
not expect money till I've received the boards and I'm ready to ship. 


Stanley

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Re: [time-nuts] PICTIC II

[Bob Bownes]

I'd like one.

On Thu, Jul 1, 2010 at 11:41 AM, Stanley Reynolds
 wrote:
> The price would be at my cost and actual shipping, no packaging or processing
> charges added by me. Not sure of price till I have the number of boards but 
> hope
> as a group we will get a better price. This would also allow us to order just 
> 1
> if that is the need. I can take paypal but that has their cost as well. I 
> would
> not expect money till I've received the boards and I'm ready to ship.
>
>
> Stanley
>
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>

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Rob Kimberley]

Interesting. 

The period of variation is approx. 50 minutes. Trying to think what that may
be related to. 

Would like to see the results taking the leading edge of the 1PPS also. I'm
assuming your location is fixed, and you are tracking sufficient SVs, as
I've seen something similar when moving.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of jmfranke
Sent: 01 July 2010 2:51 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Long period variation of GPS PPS timing?

I am not sure about the Garmin GPS16, but all of the GPS receivers I use do
not rigidly define the falling edge of the 1PPS signal.  Perhaps you should
use only the leading edges for the pulse-to-pulse interval measurement.

John  WA4WDL

--
From: "Paul Nicholson" 
Sent: Thursday, July 01, 2010 6:15 AM
To: 
Subject: [time-nuts] Long period variation of GPS PPS timing?

> I am using the PPS from a Garmin GPS16 to timestamp a VLF signal 
> received directly via a PC soundcard.  Signal into one channel, PPS 
> into the other.
>
> Using pulse centroid timing, I'm seeing about 0.5uS jitter of the 
> pulse-to-pulse interval, and an exponential moving average with time 
> constant 100 seconds is applied to smooth this out.
>
> What I have left is a slow cyclic variation of the signal 
> timestamping.
>
> It shows up when I measure the phase of an off-air signal, eg here is 
> MSF 60kHz from Anthorn.
>
>  http://abelian.org/vlf/live/pp100701msfb.png
>
> The same variation appears (in unison) on other off-air timing 
> signals, eg DCF and HBG both show the same cycle, so I guess this is 
> variation of the GPS PPS itself, not the VLF signal phase.
>
> The period is about 3000 seconds and the amplitude corresponds to 
> about +/- 1.4uS.
>
> Having no prior experience of using GPS PPS timing, I was expecting 
> some pulse-to-pulse jitter, but this slow variation has caught me by 
> surprise.  Question: is this typical of GPS timing signals, or have I 
> got a problem in my software?
> --
> Paul Nicholson
> http://abelian.org
> --
>
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


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Re: [time-nuts] PICTIC II

[Stanley Reynolds]

The price would be at my cost and actual shipping, no packaging or processing 
charges added by me. Not sure of price till I have the number of boards but 
hope 
as a group we will get a better price. This would also allow us to order just 1 
if that is the need. I can take paypal but that has their cost as well. I would 
not expect money till I've received the boards and I'm ready to ship. 


Stanley

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Re: [time-nuts] PICTIC II

[Stanley Reynolds]

OK, email me off list the number of boards and address so I can calculate 
postage and I will order them.

Stanley



- Original Message 
From: Steve Rooke 
To: Discussion of precise time and frequency measurement 
Sent: Thu, July 1, 2010 8:34:57 AM
Subject: Re: [time-nuts] PICTIC II

Me too!

On 2 July 2010 00:50, Jeroen Bastemeijer  wrote:
> Dear Richard, and other Time-Nuts,
>
> Congratulations! Looks like a very nice design!
>
> One remark and one question:
>
> * Remark: For those running a non-windows-OS, use Virtualbox (for exampe the
> free version from Oracle). This works perfect and allows e.g. Linux users to
> run windows applications, like ExpressPCB.
>
> * Question: Is there someone in the US willing to organize a group-buy of
> PCBs? When people from outside the US want to order ExpressPCB boards they
> have to pay about the double prices and taxes will be added This would
> make 17USD board (3 for 51USD as metioned by Richard) cost around 60 USD per
> board(!) (including shipping overseas, taxes and duties).
>
> This project looks very nice for doing some experiments. I had a fun time
> playing with the simple Pictic, looking forward to playing with the Pictic
> II!
>
> Best regards, Jeroen
>
> Richard H McCorkle wrote:
>>
>> Time-Nuts,
>>
>> The PICTIC WIKI page has been updated to include a PDF of the
>> schematic and board layout as requested.
>>
>> Richard
>>
>>
>>
>>>
>>> On 06/28/2010 01:46 AM, Stanley Reynolds wrote:
>>>

 done

 www.n4iqt.com/picticii/circuit.jpg

 www.n4iqt.com/picticii/PICTICII.bmp

 both above as pdf

 www.n4iqt.com/picticii/circuit-pcb.pdf

>>>
>>> Looks like page 2 of the schematic isn't there. The analog interpolator
>>> is there... if the overall schematic is anything like the PICTIC.
>>>
>>> I was unable to open up the schematic, but I may have made a mistake...
>>>
>>> Cheers,
>>> Magnus
>>>
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>>
>>
>>
>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
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>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
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-- 
Steve Rooke - ZL3TUV & G8KVD
The only reason for time is so that everything doesn't happen at once.
- Einstein

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Re: [time-nuts] Long period variation of GPS PPS timing?

[jmfranke]

I am not sure about the Garmin GPS16, but all of the GPS receivers I use do 
not rigidly define the falling edge of the 1PPS signal.  Perhaps you should 
use only the leading edges for the pulse-to-pulse interval measurement.


John  WA4WDL

--
From: "Paul Nicholson" 
Sent: Thursday, July 01, 2010 6:15 AM
To: 
Subject: [time-nuts] Long period variation of GPS PPS timing?


I am using the PPS from a Garmin GPS16 to timestamp a VLF
signal received directly via a PC soundcard.  Signal into one
channel, PPS into the other.

Using pulse centroid timing, I'm seeing about 0.5uS jitter of
the pulse-to-pulse interval, and an exponential moving average
with time constant 100 seconds is applied to smooth this out.

What I have left is a slow cyclic variation of the signal
timestamping.

It shows up when I measure the phase of an off-air signal,
eg here is MSF 60kHz from Anthorn.

 http://abelian.org/vlf/live/pp100701msfb.png

The same variation appears (in unison) on other off-air timing
signals, eg DCF and HBG both show the same cycle, so I guess
this is variation of the GPS PPS itself, not the VLF signal phase.

The period is about 3000 seconds and the amplitude corresponds
to about +/- 1.4uS.

Having no prior experience of using GPS PPS timing, I was
expecting some pulse-to-pulse jitter, but this slow variation
has caught me by surprise.  Question: is this typical of GPS
timing signals, or have I got a problem in my software?
--
Paul Nicholson
http://abelian.org
--

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Re: [time-nuts] PICTIC II

[Steve Rooke]

Me too!

On 2 July 2010 00:50, Jeroen Bastemeijer  wrote:
> Dear Richard, and other Time-Nuts,
>
> Congratulations! Looks like a very nice design!
>
> One remark and one question:
>
> * Remark: For those running a non-windows-OS, use Virtualbox (for exampe the
> free version from Oracle). This works perfect and allows e.g. Linux users to
> run windows applications, like ExpressPCB.
>
> * Question: Is there someone in the US willing to organize a group-buy of
> PCBs? When people from outside the US want to order ExpressPCB boards they
> have to pay about the double prices and taxes will be added This would
> make 17USD board (3 for 51USD as metioned by Richard) cost around 60 USD per
> board(!) (including shipping overseas, taxes and duties).
>
> This project looks very nice for doing some experiments. I had a fun time
> playing with the simple Pictic, looking forward to playing with the Pictic
> II!
>
> Best regards, Jeroen
>
> Richard H McCorkle wrote:
>>
>> Time-Nuts,
>>
>> The PICTIC WIKI page has been updated to include a PDF of the
>> schematic and board layout as requested.
>>
>> Richard
>>
>>
>>
>>>
>>> On 06/28/2010 01:46 AM, Stanley Reynolds wrote:
>>>

 done

 www.n4iqt.com/picticii/circuit.jpg

 www.n4iqt.com/picticii/PICTICII.bmp

 both above as pdf

 www.n4iqt.com/picticii/circuit-pcb.pdf

>>>
>>> Looks like page 2 of the schematic isn't there. The analog interpolator
>>> is there... if the overall schematic is anything like the PICTIC.
>>>
>>> I was unable to open up the schematic, but I may have made a mistake...
>>>
>>> Cheers,
>>> Magnus
>>>
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>>
>>
>>
>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
> ___
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> To unsubscribe, go to
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> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
The only reason for time is so that everything doesn't happen at once.
- Einstein

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Re: [time-nuts] PICTIC II

[EWKehren]

Lets see what Richard says. I have just gone through that with my D/M which 
 is in its second test phase and I did ship boards oversees. May do that 
one  time.
Bert
 
 
In a message dated 7/1/2010 9:13:57 A.M. Eastern Daylight Time,  
j.bastemei...@tudelft.nl writes:

Dear  Richard, and other Time-Nuts,

Congratulations! Looks like a very nice  design!

One remark and one question:

* Remark: For those running  a non-windows-OS, use Virtualbox (for exampe 
the free version from  Oracle). This works perfect and allows e.g. Linux 
users to run windows  applications, like ExpressPCB.

* Question: Is there someone in the US  willing to organize a group-buy 
of PCBs? When people from outside the US  want to order ExpressPCB boards 
they have to pay about the double prices  and taxes will be added 
This would make 17USD board (3 for 51USD as  metioned by Richard) cost 
around 60 USD per board(!) (including shipping  overseas, taxes and duties).

This project looks very nice for doing  some experiments. I had a fun 
time playing with the simple Pictic, looking  forward to playing with the 
Pictic II!

Best regards,  Jeroen

Richard H McCorkle wrote:
> Time-Nuts,
>
> The  PICTIC WIKI page has been updated to include a PDF of the
> schematic  and board layout as requested.
>
>  Richard
>
>
>   
>> On 06/28/2010 01:46  AM, Stanley Reynolds wrote:
>> 
>>>  done
>>>
>>>  www.n4iqt.com/picticii/circuit.jpg
>>>
>>>  www.n4iqt.com/picticii/PICTICII.bmp
>>>
>>> both above  as pdf
>>>
>>>  www.n4iqt.com/picticii/circuit-pcb.pdf
>>> 
>> Looks like page 2 of the schematic isn't there. The  analog interpolator
>> is there... if the overall schematic is  anything like the PICTIC.
>>
>> I was unable to open up the  schematic, but I may have made a mistake...
>>
>>  Cheers,
>> Magnus
>>
>>  ___
>> time-nuts mailing  list -- time-nuts@febo.com
>> To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow  the instructions there.
>>
>>  
>
>
>
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Re: [time-nuts] PICTIC II

[Jeroen Bastemeijer]

Dear Richard, and other Time-Nuts,

Congratulations! Looks like a very nice design!

One remark and one question:

* Remark: For those running a non-windows-OS, use Virtualbox (for exampe 
the free version from Oracle). This works perfect and allows e.g. Linux 
users to run windows applications, like ExpressPCB.


* Question: Is there someone in the US willing to organize a group-buy 
of PCBs? When people from outside the US want to order ExpressPCB boards 
they have to pay about the double prices and taxes will be added 
This would make 17USD board (3 for 51USD as metioned by Richard) cost 
around 60 USD per board(!) (including shipping overseas, taxes and duties).


This project looks very nice for doing some experiments. I had a fun 
time playing with the simple Pictic, looking forward to playing with the 
Pictic II!


Best regards, Jeroen

Richard H McCorkle wrote:

Time-Nuts,

The PICTIC WIKI page has been updated to include a PDF of the
schematic and board layout as requested.

Richard


  

On 06/28/2010 01:46 AM, Stanley Reynolds wrote:


done

www.n4iqt.com/picticii/circuit.jpg

www.n4iqt.com/picticii/PICTICII.bmp

both above as pdf

www.n4iqt.com/picticii/circuit-pcb.pdf
  

Looks like page 2 of the schematic isn't there. The analog interpolator
is there... if the overall schematic is anything like the PICTIC.

I was unable to open up the schematic, but I may have made a mistake...

Cheers,
Magnus

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Re: [time-nuts] Long period variation of GPS PPS timing?

[asmagal]

Hello!

If considered useful, I can send you the yesterday record of my GPS
TBolt #2 against DCF77, which apparently doesn't show any periodic
phase variation. The VLF receiver is a Tracor 599K and the chart
span is 10 uS. If there was such a variation it should be clearly
visible.

Antonio
CT1TE

Quoting Peter Vince :


Hi Paul,

 Others on this list will reply more authoritatively, but I don't
believe that cyclic variability is GPS - I've not noticed such a thing
on any of the systems I monitor.  Can you carefully monitor
temperature and PSU voltage, and maybe find a correlation there?

 Peter

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Re: [time-nuts] Long period variation of GPS PPS timing?

[Peter Vince]

Hi Paul,

 Others on this list will reply more authoritatively, but I don't
believe that cyclic variability is GPS - I've not noticed such a thing
on any of the systems I monitor.  Can you carefully monitor
temperature and PSU voltage, and maybe find a correlation there?

 Peter

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[time-nuts] Long period variation of GPS PPS timing?

[Paul Nicholson]

I am using the PPS from a Garmin GPS16 to timestamp a VLF
signal received directly via a PC soundcard.  Signal into one
channel, PPS into the other.

Using pulse centroid timing, I'm seeing about 0.5uS jitter of
the pulse-to-pulse interval, and an exponential moving average
with time constant 100 seconds is applied to smooth this out.

What I have left is a slow cyclic variation of the signal
timestamping.

It shows up when I measure the phase of an off-air signal,
eg here is MSF 60kHz from Anthorn.

 http://abelian.org/vlf/live/pp100701msfb.png

The same variation appears (in unison) on other off-air timing
signals, eg DCF and HBG both show the same cycle, so I guess
this is variation of the GPS PPS itself, not the VLF signal phase.

The period is about 3000 seconds and the amplitude corresponds
to about +/- 1.4uS.

Having no prior experience of using GPS PPS timing, I was
expecting some pulse-to-pulse jitter, but this slow variation
has caught me by surprise.  Question: is this typical of GPS
timing signals, or have I got a problem in my software?
--
Paul Nicholson
http://abelian.org
--

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