Re: [time-nuts] fleabay cesium

2009-05-10 Thread Magnus Danielson

WB6BNQ skrev:


Lets try to put this into perspective !   Using the specs from the OLD hp 5061A
which says it is intrinsically accurate to 1 part in 10^-11 means the following
assuming it is exactly in error by a stable value of 1 x 10^-11 from the agreed
upon central value :

1 x 10^-11 = 10 picoseconds offset


This is when we should have looked at the TDEV charts rather than the 
ADEV charts and include linear terms for the full prediction.


Cheers,
Magnus

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[time-nuts] Help needed: Jupiter-T TU60-D120

2009-05-10 Thread Lasse
I got a Jupiter-T TU60 off eBay and my intentions are (was) to get a 
diciplined oscillator running.
Somehow I expected it to be pretty similar (command wise) to a TU-30 
wich is up and running here, but must have missed the information that

it starts in Motorola Bin??

My TU60 will just say "ff 81 9c 04 01 00 00 00 64 79 00 00 00 00"  at 
power-up (Message ID 1180) once, then nothing.
After installing TAC32 (demo) yesterday I managed (don't ask me how) get 
the uint running, everything looked OK,  I then wanted to put it inot 
Navman Bin mode. This should be safe as according to datasheet as it 
will revert to Motorola commands when cycling the power. After trying 
@@Wb, but nothing from Labmon/WinLabmon, and  now TAC32 cannot get in 
contact with the GPS,
I let the GPS be off power over night but it sill refuses to connect to 
TAC32.


Have I put my Jupiter in a mode that I cannot revert? It still reports 
the MessageID 1180 at power-on.
Or was I just plain lucky once to somhow fool TAC32 to get the Jupiter 
to run?


Any hints or comments are most welcome!

/Lasse


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[time-nuts] GPS->audio interface

2009-05-10 Thread Lux, James P
I'm looking for a way to take GPS time and generate a signal that can be 
recorded on the audio track of a video recording to time stamp it. This is so 
it can be aligned with other data that's collected with GPS based time.  It 
needs to be portable/small (i.e. Something you could attach to a small 
camcorder, or such).

Seems that a GPS->IRIG B interface would work, but I was wondering if someone 
has done this already (e.g. Someone must have made a IRIG encoder in a PIC or 
similar)..

Another alternate is if something like a iPhone records accurate time with the 
video stream. (another of the data sources is an iPhone recording something 
else)

I think the basic requirement is accuracy to some few milliseconds (e.g. Frame 
rate of the video)..

(It's for a high school science project, where they want to record various 
things, and line them up.. I think they could deal with looking at the 
timestamps over many frames to do interpolation)

Anyway, cheap and cheerful consumer gear is what is sought. (so no suggestions 
of synthesizing SMPTE from the output of my Z3801 and feeding it to a RED 
camera.. We're talking AIPtek and iPhone here..)

Jim Lux
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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Magnus Danielson

Lux, James P skrev:

I'm looking for a way to take GPS time and generate a signal that can
be recorded on the audio track of a video recording to time stamp it.
This is so it can be aligned with other data that's collected with GPS
based time.  It needs to be portable/small (i.e. Something you could
attach to a small camcorder, or such).


Traditionally SMPTE 12M LTC is being used for this purpose. For most 
cases it is only known as LTC but SMPTE/EBU time code is among other 
names fairly common name.



Seems that a GPS->IRIG B interface would work, but I was wondering if
someone has done this already (e.g. Someone must have made a IRIG
encoder in a PIC or similar)..


I actually have a GPS with IRIG-B output in about the same size of a 
Thunderbolt. If you have your own encoder in the form of a PIC/AVR then 
maybe producing SMPTE LTC should be better or at least considered as an 
alternative output.



Another alternate is if something like a iPhone records accurate time
with the video stream. (another of the data sources is an iPhone
recording something else)

I think the basic requirement is accuracy to some few milliseconds
(e.g. Frame rate of the video)..


SMPTE LTC encodes the frame numbers.


(It's for a high school science project, where they want to record
various things, and line them up.. I think they could deal with
looking at the timestamps over many frames to do interpolation)


SMPTE LTC should be preferred in that case, as it is something that 
editing equipment understands.



Anyway, cheap and cheerful consumer gear is what is sought. (so no
suggestions of synthesizing SMPTE from the output of my Z3801 and
feeding it to a RED camera.. We're talking AIPtek and iPhone here..)


Locking the camera with a black burst GENLOCK signal with VITC does need 
to be done, but the LTC may very well be practical for the purpose.


BTW. Cameras lacking GENLOCK is highly annoying, especially when they 
have el cheapo crystals... el cheapo crystals is fine, as long as they 
lock up to a GENLOCK when needed.


Cheers,
Magnus

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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Lux, James P



On 5/10/09 11:21 AM, "Magnus Danielson"  wrote:

> Lux, James P skrev:
>> I'm looking for a way to take GPS time and generate a signal that can
>> be recorded on the audio track of a video recording to time stamp it.
>> This is so it can be aligned with other data that's collected with GPS
>> based time.  It needs to be portable/small (i.e. Something you could
>> attach to a small camcorder, or such).
> 
> Traditionally SMPTE 12M LTC is being used for this purpose. For most
> cases it is only known as LTC but SMPTE/EBU time code is among other
> names fairly common name.
> 
Yes.. But most consumer recorders (e.g. The cheap AIPtek) don't do timecode
(or genlock, or other useful stuff)..

So what they're really looking for is someway to time align after the fact.

> I actually have a GPS with IRIG-B output in about the same size of a
> Thunderbolt.

Is that an off the shelf, not hideously expensive, widget?  (There are other
applications...)
> 
>> Another alternate is if something like a iPhone records accurate time
>> with the video stream. (another of the data sources is an iPhone
>> recording something else)
>> 
>> I think the basic requirement is accuracy to some few milliseconds
>> (e.g. Frame rate of the video)..
> 
> SMPTE LTC encodes the frame numbers.
> 
>> (It's for a high school science project, where they want to record
>> various things, and line them up.. I think they could deal with
>> looking at the timestamps over many frames to do interpolation)
> 
> SMPTE LTC should be preferred in that case, as it is something that
> editing equipment understands.

I don't think "real" editing gear is in the cards.  Probably more like
iMovie or something on a PC.

As a model for what they're trying to do, say you were going to measure the
acceleration due to gravity by videotaping a falling object against a scale
in the background. Except that the motion is more complex.. Maybe imagine
putting an accelerometer in the "payload" of a trebuchet... And you want to
time align the position of the trebuchet components (from the video) with
the forces on the payload. That's not what they're doing, but now that I
describe it, that WOULD be a cool science project.  And get away from the
"here, I built a trebuchet and launched a projectile X meters" which is kind
of tired.  (get one of those analog devices 3 axis accelerometers, hook it
to a suitable datalogger..)


> 
>> Anyway, cheap and cheerful consumer gear is what is sought. (so no
>> suggestions of synthesizing SMPTE from the output of my Z3801 and
>> feeding it to a RED camera.. We're talking AIPtek and iPhone here..)
> 
> Locking the camera with a black burst GENLOCK signal with VITC does need
> to be done, but the LTC may very well be practical for the purpose.
> 
> BTW. Cameras lacking GENLOCK is highly annoying, especially when they
> have el cheapo crystals... el cheapo crystals is fine, as long as they
> lock up to a GENLOCK when needed.


That pretty well describes just about everything they'll have available.


> 
> Cheers,
> Magnus
> 
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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Hal Murray

> As a model for what they're trying to do, say you were going to
> measure the acceleration due to gravity by videotaping a falling
> object against a scale in the background. Except that the motion is
> more complex.. Maybe imagine putting an accelerometer in the "payload"
> of a trebuchet... And you want to time align the position of the
> trebuchet components (from the video) with the forces on the payload.
> That's not what they're doing, but now that I describe it, that WOULD
> be a cool science project.  And get away from the "here, I built a
> trebuchet and launched a projectile X meters" which is kind of tired.
> (get one of those analog devices 3 axis accelerometers, hook it to a
> suitable datalogger..) 

For something like that, you could:
  start the camera
  start the recorder in the payload
  whack the payload with a stick to inject a calibration marker
(the stick has to be visible in the camera)
  maybe re-aim the camera
  launch the payload...

 

-- 
These are my opinions, not necessarily my employer's.  I hate spam.




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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Brooke Clarke

Hi James:

You might want to get a KIWI-OSD, Video overlay of GPS precision time 
stamp.  It adds HH:MM:SS   FF at the bottom of the image and 
so can be seen in every field.  They have also developed a way to 
calibrate the camera shutter in relation to the frame time by using a 
number of LEDs.  The main use if for star occulation timing.

http://www.geocities.com/kiwi_36_nz/kiwi_osd/kiwi_osd.htm

Have Fun,

Brooke Clarke
http://www.prc68.com



Lux, James P wrote:

I'm looking for a way to take GPS time and generate a signal that can be 
recorded on the audio track of a video recording to time stamp it. This is so 
it can be aligned with other data that's collected with GPS based time.  It 
needs to be portable/small (i.e. Something you could attach to a small 
camcorder, or such).

Seems that a GPS->IRIG B interface would work, but I was wondering if someone 
has done this already (e.g. Someone must have made a IRIG encoder in a PIC or 
similar)..

Another alternate is if something like a iPhone records accurate time with the 
video stream. (another of the data sources is an iPhone recording something 
else)

I think the basic requirement is accuracy to some few milliseconds (e.g. Frame 
rate of the video)..

(It's for a high school science project, where they want to record various 
things, and line them up.. I think they could deal with looking at the 
timestamps over many frames to do interpolation)

Anyway, cheap and cheerful consumer gear is what is sought. (so no suggestions 
of synthesizing SMPTE from the output of my Z3801 and feeding it to a RED 
camera.. We're talking AIPtek and iPhone here..)

Jim Lux
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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Magnus Danielson

Lux, James P skrev:



On 5/10/09 11:21 AM, "Magnus Danielson"  wrote:


Lux, James P skrev:

I'm looking for a way to take GPS time and generate a signal that can
be recorded on the audio track of a video recording to time stamp it.
This is so it can be aligned with other data that's collected with GPS
based time.  It needs to be portable/small (i.e. Something you could
attach to a small camcorder, or such).

Traditionally SMPTE 12M LTC is being used for this purpose. For most
cases it is only known as LTC but SMPTE/EBU time code is among other
names fairly common name.


Yes.. But most consumer recorders (e.g. The cheap AIPtek) don't do timecode
(or genlock, or other useful stuff)..


They should be hackable thought.


So what they're really looking for is someway to time align after the fact.


This does not prohibit you from just recording the LTC onto the 
soundtrack anyway.



I actually have a GPS with IRIG-B output in about the same size of a
Thunderbolt.


Is that an off the shelf, not hideously expensive, widget?  (There are other
applications...)


I bought one of those Brandywine GPS4 devices as announced available on 
the list not too long ago. Not hideously expensive IMHO.



Another alternate is if something like a iPhone records accurate time
with the video stream. (another of the data sources is an iPhone
recording something else)

I think the basic requirement is accuracy to some few milliseconds
(e.g. Frame rate of the video)..

SMPTE LTC encodes the frame numbers.


(It's for a high school science project, where they want to record
various things, and line them up.. I think they could deal with
looking at the timestamps over many frames to do interpolation)

SMPTE LTC should be preferred in that case, as it is something that
editing equipment understands.


I don't think "real" editing gear is in the cards.  Probably more like
iMovie or something on a PC.


There should be editing gear that chews LTC over audio-interface. We did 
frame-grabbing tricks with a cheap video-recorder, LTC on audio track 
and an SGI Indy back in the days... and a remote hacked with CMOS 
switches steered by a DTMF decoder so the Indy played DTMF tone-pairs on 
the port, real-time decoded LTC and frame-grabbed 10 frames at the time, 
rewinded, played again etc. Some of the cheap/free programmes would be 
able to decode LTC and tag the pictures accordingly.



As a model for what they're trying to do, say you were going to measure the
acceleration due to gravity by videotaping a falling object against a scale
in the background. Except that the motion is more complex.. Maybe imagine
putting an accelerometer in the "payload" of a trebuchet... And you want to
time align the position of the trebuchet components (from the video) with
the forces on the payload. That's not what they're doing, but now that I
describe it, that WOULD be a cool science project.  And get away from the
"here, I built a trebuchet and launched a projectile X meters" which is kind
of tired.  (get one of those analog devices 3 axis accelerometers, hook it
to a suitable datalogger..)


In that case you want the line-frequency locked or traceable by other 
means. You have more use for the frequency aspect than time-notation 
actually, which is more handy for a matter logging which event. Still, 
LTC should be easier to get locked to the phase attached to the frames, 
as the infrastructure is expected to be there for some apps, but the 
IRIG-B support is not expected to be there.


If you do not hack the camera to accept a reference signal (hacking the 
crystal oscillator may be all you need to do), after the fact frequency 
calibration can be done with either IRIG-B, LTC or just a 1 kHz sine.



Anyway, cheap and cheerful consumer gear is what is sought. (so no
suggestions of synthesizing SMPTE from the output of my Z3801 and
feeding it to a RED camera.. We're talking AIPtek and iPhone here..)

Locking the camera with a black burst GENLOCK signal with VITC does need
to be done, but the LTC may very well be practical for the purpose.

BTW. Cameras lacking GENLOCK is highly annoying, especially when they
have el cheapo crystals... el cheapo crystals is fine, as long as they
lock up to a GENLOCK when needed.



That pretty well describes just about everything they'll have available.


Well, the two initial strategies is to either hack the cameras and 
replace the XO with a VCXO which locks to a 10 Mhz. Usually it is 27 MHz 
 and relationship to 10 MHz is fairly trivial. After the fact 
synchronisation using a 1 kHz signal (such as given by TADD-2, tvb 
PIC-div or something) into the audio signal would also do, if only the 
audio sample rate and the video rate is locked in the el cheapo camera, 
which one can hope for at least.


Cheers,
Magnus

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[time-nuts] GPS L5 received, according to Javad

2009-05-10 Thread Poul-Henning Kamp

http://www.javad.com/jgnss/javad/news/pr20090424.html

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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Re: [time-nuts] GPS L5 received, according to Javad

2009-05-10 Thread Brooke Clarke

Hi Poul:

That should allow better determination of the propagation path length 
when combined with the L1 C/A signal.
Next year when L1CS, L1CM, L1CL, L2CS, L2CM and L2CL signals are added 
it's going to really get interesting.


Does Javad make a timing receiver?

Have Fun,

Brooke Clarke
http://www.prc68.com



Poul-Henning Kamp wrote:

http://www.javad.com/jgnss/javad/news/pr20090424.html

  


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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Bruce Griffiths
Brooke

The KIWI-OSD is no longer available.
However some circuit detail is available at:
http://spiff.rit.edu/richmond/ritobs/kiwi/kiwi.html

It really should be reworked to use a more reliable time source such as
a GPS timing receiver.

Bruce

Brooke Clarke wrote:
> Hi James:
>
> You might want to get a KIWI-OSD, Video overlay of GPS precision time
> stamp.  It adds HH:MM:SS   FF at the bottom of the image
> and so can be seen in every field.  They have also developed a way to
> calibrate the camera shutter in relation to the frame time by using a
> number of LEDs.  The main use if for star occulation timing.
> http://www.geocities.com/kiwi_36_nz/kiwi_osd/kiwi_osd.htm
>
> Have Fun,
>
> Brooke Clarke
> http://www.prc68.com
>
>
>
> Lux, James P wrote:
>> I'm looking for a way to take GPS time and generate a signal that can
>> be recorded on the audio track of a video recording to time stamp it.
>> This is so it can be aligned with other data that's collected with
>> GPS based time.  It needs to be portable/small (i.e. Something you
>> could attach to a small camcorder, or such).
>>
>> Seems that a GPS->IRIG B interface would work, but I was wondering if
>> someone has done this already (e.g. Someone must have made a IRIG
>> encoder in a PIC or similar)..
>>
>> Another alternate is if something like a iPhone records accurate time
>> with the video stream. (another of the data sources is an iPhone
>> recording something else)
>>
>> I think the basic requirement is accuracy to some few milliseconds
>> (e.g. Frame rate of the video)..
>>
>> (It's for a high school science project, where they want to record
>> various things, and line them up.. I think they could deal with
>> looking at the timestamps over many frames to do interpolation)
>>
>> Anyway, cheap and cheerful consumer gear is what is sought. (so no
>> suggestions of synthesizing SMPTE from the output of my Z3801 and
>> feeding it to a RED camera.. We're talking AIPtek and iPhone here..)
>>
>> Jim Lux
>> ___
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>
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Re: [time-nuts] GPS L5 received, according to Javad

2009-05-10 Thread bg
Hi Brooke,

> Hi Poul:
>
> That should allow better determination of the propagation path length
> when combined with the L1 C/A signal.
> Next year when L1CS, L1CM, L1CL, L2CS, L2CM and L2CL signals are added
> it's going to really get interesting.
>
> Does Javad make a timing receiver?

Yes. You pay about $600 extra for the Frequency Input option.

   http://www.javad.com/cgi-bin/jgnss/cgi?Action=Buy&ProductID=663

--

   Björn


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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Lux, James P



On 5/10/09 12:10 PM, "Hal Murray"  wrote:

> 
> 
>> As a model for what they're trying to do, say you were going to
>> measure the acceleration due to gravity by videotaping a falling
>> object against a scale in the background. Except that the motion is
>> more complex.. Maybe imagine putting an accelerometer in the "payload"
>> of a trebuchet... And you want to time align the position of the
>> trebuchet components (from the video) with the forces on the payload.
>> That's not what they're doing, but now that I describe it, that WOULD
>> be a cool science project.  And get away from the "here, I built a
>> trebuchet and launched a projectile X meters" which is kind of tired.
>> (get one of those analog devices 3 axis accelerometers, hook it to a
>> suitable datalogger..)
> 
> For something like that, you could:
>   start the camera
>   start the recorder in the payload
>   whack the payload with a stick to inject a calibration marker
> (the stick has to be visible in the camera)
>   maybe re-aim the camera
>   launch the payload...
> 
> 
> 
Yes.. This is called a "slate" or "clapper board" in the movie trade.


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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Lux, James P



On 5/10/09 12:15 PM, "Brooke Clarke"  wrote:

> Hi James:
> 
> You might want to get a KIWI-OSD, Video overlay of GPS precision time
> stamp.  It adds HH:MM:SS   FF at the bottom of the image and
> so can be seen in every field.  They have also developed a way to
> calibrate the camera shutter in relation to the frame time by using a
> number of LEDs.  The main use if for star occulation timing.
> http://www.geocities.com/kiwi_36_nz/kiwi_osd/kiwi_osd.htm
> 
> Have Fun,
> 
> Brooke Clarke

Yes, but that requires getting access to the video stream, which isn't easy
in a "camcorder" environment.  Separate video recorders actually cost more
than camcorders.


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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Magnus Danielson

Lux, James P skrev:



On 5/10/09 12:15 PM, "Brooke Clarke"  wrote:


Hi James:

You might want to get a KIWI-OSD, Video overlay of GPS precision time
stamp.  It adds HH:MM:SS   FF at the bottom of the image and
so can be seen in every field.  They have also developed a way to
calibrate the camera shutter in relation to the frame time by using a
number of LEDs.  The main use if for star occulation timing.
http://www.geocities.com/kiwi_36_nz/kiwi_osd/kiwi_osd.htm

Have Fun,

Brooke Clarke


Yes, but that requires getting access to the video stream, which isn't easy
in a "camcorder" environment.  Separate video recorders actually cost more
than camcorders.


What precision of anything do you need?

Expect 50-100 ppm oscillators in there.

Recorded material is compressed. Consider how that affects your readout.
Recorded material is said progressive/interlaced. This may not reflect 
how the CCD is snapshot and readout. You may not have the expected 1125 
or 750 lines per frame, and exactly what frame rate do you have?


Cheers,
Magnus

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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Neville Michie

Hi,
 low tech solution may be to produce second pips of audio with long  
one minute pips,
a bit like WWV, and inject them into the mic plug (in parallel to the  
mic) or use a small speaker.
That together with a clap-board start should enable any frame to be  
timed.

cheers, Neville Michie


On 11/05/2009, at 3:48 AM, Lux, James P wrote:

I'm looking for a way to take GPS time and generate a signal that  
can be recorded on the audio track of a video recording to time  
stamp it. This is so it can be aligned with other data that's  
collected with GPS based time.  It needs to be portable/small (i.e.  
Something you could attach to a small camcorder, or such).


Seems that a GPS->IRIG B interface would work, but I was wondering  
if someone has done this already (e.g. Someone must have made a  
IRIG encoder in a PIC or similar)..


Another alternate is if something like a iPhone records accurate  
time with the video stream. (another of the data sources is an  
iPhone recording something else)


I think the basic requirement is accuracy to some few milliseconds  
(e.g. Frame rate of the video)..


(It's for a high school science project, where they want to record  
various things, and line them up.. I think they could deal with  
looking at the timestamps over many frames to do interpolation)


Anyway, cheap and cheerful consumer gear is what is sought. (so no  
suggestions of synthesizing SMPTE from the output of my Z3801 and  
feeding it to a RED camera.. We're talking AIPtek and iPhone here..)


Jim Lux
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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Lux, James P



On 5/10/09 4:26 PM, "Magnus Danielson"  wrote:

> Lux, James P skrev:
>> 
>> 
>> On 5/10/09 12:15 PM, "Brooke Clarke"  wrote:
>> 
>>> Hi James:
>>> 
>>> You might want to get a KIWI-OSD, Video overlay of GPS precision time
>>> stamp.  It adds HH:MM:SS   FF at the bottom of the image and
>>> so can be seen in every field.  They have also developed a way to
>>> calibrate the camera shutter in relation to the frame time by using a
>>> number of LEDs.  The main use if for star occulation timing.
>>> http://www.geocities.com/kiwi_36_nz/kiwi_osd/kiwi_osd.htm
>>> 
>>> Have Fun,
>>> 
>>> Brooke Clarke
>> 
>> Yes, but that requires getting access to the video stream, which isn't easy
>> in a "camcorder" environment.  Separate video recorders actually cost more
>> than camcorders.
> 
> What precision of anything do you need?
> 
> Expect 50-100 ppm oscillators in there.
> 

Yes, but probably fairly good in the short run, and if you were recording
almost any sync signal (e.g. The 1kHz sine) you could calibrate that out.

> 
> 
> 
> Recorded material is compressed. Consider how that affects your readout.
> Recorded material is said progressive/interlaced. This may not reflect
> how the CCD is snapshot and readout. You may not have the expected 1125
> or 750 lines per frame, and exactly what frame rate do you have?

I think that's something they'll need to experiment with...

Jim


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[time-nuts] HP 117A Manual.

2009-05-10 Thread Max Robinson

Hi All.

I now have the HP 117A but I find it has been modified for a 12 volt 
antenna.  Looking inside I find a 3 terminal regulator that could be a 
factory mod except it is on perf board.  Judging by the wires that come out 
of the harness I would say there used to be something in that place.  The 
voltage coming to the regulator is about 33 volts but the seller informs me 
that there is an antenna voltage adjustment.  I suppose the voltage was set 
to minimum to reduce dissipation in the regulator.  I am wondering what went 
where that regulator is now.  Maybe a thermistor to limit the inrush current 
to the antenna?  I am hesitant to just take out the regulator and solder the 
ends of the wires together, excluding the ground of course.  If anyone has a 
manual you have already scanned I would appreciate receiving it.


Regards.

Max.  K 4 O D S.

Email: m...@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com

To subscribe to the fun with tubes group send an email to,
funwithtubes-subscr...@yahoogroups.com

- Original Message - 
From: "Mark Sims" 

To: 
Sent: Saturday, May 02, 2009 7:24 PM
Subject: [time-nuts] Chart recorder consumables (was HP 117 paper)



Don't know what it fits,  but it's cheap  Ebay item 120412680477.  It is 
apparently 6" wide, trac drive.

_
Hotmail® goes with you.
http://windowslive.com/Tutorial/Hotmail/Mobile?ocid=TXT_TAGLM_WL_HM_Tutorial_Mobile1_052009
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Re: [time-nuts] GPS->audio interface

2009-05-10 Thread Dean Weiten
Hi there,

It turns out that the NTP package has a built-in utility called "tg"
which can generate IRIG-B time code.  I'm not familiar with what you are
trying to do.  If you have a computer that is keeping accurate time
(through your GPS clock??), you can generate a nice audio IRIG-B.  It
was developed to allow testing of the NTP IRIG-B **input** function. 
NTP has a bunch of front ends for all kinds of code inputs.

I played with tg from NTP 4.2.2p3 quite extensively some time ago, and
created a version with a bunch more options, including IEEE 1344
extensions, and corrected a couple of bugs etc.  Also, I play a bit with
the timing to allow "tg" to omit or insert strategic single cycles to
correct for the clock error on the audio card.   Plus much more, mostly
to help me test an IRIG-B decoder. 

Oh yes, I also did a bunch of adjustments to the WWV(H) output option
from "tg".  Not many folks care about WWV(H) any more, though :-)

I'm not sure if any of you would be interested in this modified "tg". 
Let me know if you do.  I had submitted it to the NTP gurus some time
ago, and they didn't seem too terribly interested.

Regards,

Dean Weiten.

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