Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[David Kirkby]

On 20 February 2013 00:58, Paul Cianciolo  wrote:

> The purpose of this apparatus is to print a rolling chart on the screen of a 
> computer of heart BPM and then try different technicues of meditaion  and 
> calming technicues to lower my heart rate for short periods of time.

Just a warning, from someone with a Ph.D. in Medical Physics. Unless
you REALLY know what you are doing, all this should be battery
powered. I don't claim to be an expert on the rules, but using typical
commerical power supplies driven from the main is not acceptable for
medical applications.

Dave.
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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Hendrik Dietrich]

Good morning Paul,

First: I almost spilled my coffe as you bear a similar last name as a
guy at a national research lab who does exactly such things :)

Even when it makes your ECG preamplifier free for other things, I advise
you to use another sensor and put a lot of decoding and interpretation
to your brain.

ECG is not easy from a safety standpoint, as it connects to the body
immediately. The Signal is quite complex as it is composed of not a
single but a "burst" of waves during excitation and contains a lot of
moving and electrode artifacts, I wouldn't try to count BPM except AD
conversion and doing a lot of filtering and preprocessing in software.

I would use photoplethysmography instead of ECG, means you shine a
little light from a LED thru your finger or ear to a photodiode.
Actually a optocoupler with a bit of you inbetween !
The light at the photodiode will fade up and down with the local
relative blood pressure in the tissue between the emitter and receiver,
and so does the photodiode current. The resulting signal contains way
less movement artifacts and less high-frequency parts.

to record it on a PC i would say generate a audible AM-modulated tone
with the photodiode current (amplified by an TIA) as modulation, when
you feed that to the soundcard you can record with audacity and you will
see the envelope on screen where you can count the (single) peaks per
minute. For a more immediate result without PC, hook the TIA output to a
V/F converter in the audible range and hook it up to a speaker, its
easier to listen to the pitch changing.

At work I am hooked up to heart-signal-analysing thingies quite often
and i can tell you that it is easy to change heart-rate and relative
blood pressure by will in a certain range. I made it a obligatory task
to students, visitors and new co-workers to prove that they have a
heartbeat ! :)

Best regards

Hendrik

P.S.1.: My first post at the time-nuts
P.S.2.: Don't let the FDA see anything :)



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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Tom Van Baak (Lab)]

On Feb 19, 2013, at 5:38 PM, Hal Murray  wrote:

> 
> pa...@snet.net said:
>> The actual electrodes instrumentation amp is pretty much working fine  so no
>> worries there.
> 
>> My first tthought was a frequency to voltage IC like the LM2907 or the 2917
>> but I get the impresiion from the data sheets that these chips will not work
>> at these very low 1 Hz applications,
> 
> If you have clean pulses, connect them up to the PPS input on a PC serial 
> port.  The rest is software.
> 

Windows PC-based time stamping counter: http://leapsecond.com/tools/pctsc.c
But I'd opto-isolate a PC serial port before I put it too close to my heart.

/tvb
Sent from my iPad/mini
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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Jim Lux]

On 2/19/13 4:58 PM, Paul Cianciolo wrote:

Hello Folks,

I am working on a project intended to convert an analog ECG signal to
a voltage proportional the heart rate, The actual electrodes
instrumentation amp is pretty much working fine  so no worries
there.

The problem is, and here is where the relationship to time nut comes
in. The signal output from the instrumentation amplifiers will be at
a rate of approx 60 BPM or pulses, up to perhaps 90 BPM.



Interestingly, I've been doing the opposite... given a rate, generate a 
realistic pattern of beats.



The purpose of this apparatus is to print a rolling chart on the
screen of a computer of heart BPM and then try different technicues
of meditaion  and calming technicues to lower my heart rate for short
periods of time.

My first tthought was a frequency to voltage IC like the LM2907 or
the 2917 but I get the impresiion from the data sheets that these
chips will not work at these very low  1 Hz applications,

Then I thought maybe one of the frequecy counters could be configured
as a rate meter and output a proportional voltage I need. No luck
here either. Te latter components seem tobe somewhat time relatedand
that is why I posted here.\\


A small microprocessor is your friend. Run your signal into an Arduino, 
PIC, teensy (my current favorite) or whatever..


That way it can set the threshold dynamically, count time between zero 
crossings, integrate over several beats, ignore skipped or extra beats, etc.


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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[David]

The most straightforward method these days would be a small
microcontroller implementing a pulse width modulation digital to
analog converter.

The analog route is pretty easy though.  A traditional charge or
current pump can operate down to 30 Hz but will have an output ripple
versus settling time trade off.  That can be solved with a sample and
hold.

Charge balancing frequency to voltage converter on page 11:

http://cds.linear.com/docs/en/application-note/an03f.pdf

Current pump frequency to voltage converter with sample and hold
inside the feedback loop on page 4:

http://www.ti.com/lit/an/sbva005/sbva005.pdf

Given the low frequencies involved, a resetable ramp generator with
sample and hold would work great.  The fixed reset time would be so
short compared to the minimum input period that accuracy would not
significantly suffer.

On Tue, 19 Feb 2013 16:58:04 -0800 (PST), Paul Cianciolo
 wrote:

>Hello Folks,
> 
>I am working on a project intended to convert an analog ECG signal to a 
>voltage proportional the heart rate,
>The actual electrodes instrumentation amp is pretty much working fine  so no 
>worries there.
> 
>The problem is, and here is where the relationship to time nut comes in.
>The signal output from the instrumentation amplifiers will be at a rate of 
>approx 60 BPM or pulses, up to perhaps 90 BPM.
> 
>The purpose of this apparatus is to print a rolling chart on the screen of a 
>computer of heart BPM and then try different technicues of meditaion  and 
>calming technicues to lower my heart rate for short periods of time.
> 
>My first tthought was a frequency to voltage IC like the LM2907 or the 2917 
>but I get the impresiion from the data sheets that these chips will not work 
>at these very low  1 Hz applications,
> 
>Then I thought maybe one of the frequecy counters could be configured as a 
>rate meter and output a proportional voltage I need.
>No luck here either. 
>Te latter components seem tobe somewhat time relatedand that is why I posted 
>here.\\
> 
>Thank you for reading this and for any suggestions you folks might offer.
> 
>PaulC
>W1VLF
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Re: [time-nuts] Off topic project sort of heart rate monitor NEEDBEATS PRE MINUTE TO ANALOG VOLTAGE

[Tom Miller]

You can buy it for $8 COTS.

You clean up the QRS waveform with a one-shot then integrate to get rate.



- Original Message - 
From: "Bob Camp" 
To: "Discussion of precise time and frequency measurement" 


Sent: Tuesday, February 19, 2013 8:23 PM
Subject: Re: [time-nuts] Off topic project sort of heart rate monitor 
NEEDBEATS PRE MINUTE TO ANALOG VOLTAGE



Hi

The first layer to the onion is that the ECG signal is a bit complex. 
There's also likely to be a bit of this and that on it.


How about taking the output of the instrument amp into the A/D port on a 
cheap PIC? That would let you do some AGC and dynamic filtering. At even a 
modest sample rate (say 10 KHz) the heart rate could be worked out in 
software. I think I'd run a PWM out and drive an analog meter with it.


The nice thing about keeping it simple is being able to run it off a 9 volt 
battery. That takes care of a *lot* of issues.


Bob

On Feb 19, 2013, at 7:58 PM, Paul Cianciolo  wrote:


Hello Folks,

I am working on a project intended to convert an analog ECG signal to a 
voltage proportional the heart rate,
The actual electrodes instrumentation amp is pretty much working fine  so 
no worries there.


The problem is, and here is where the relationship to time nut comes in.
The signal output from the instrumentation amplifiers will be at a rate of 
approx 60 BPM or pulses, up to perhaps 90 BPM.


The purpose of this apparatus is to print a rolling chart on the screen of 
a computer of heart BPM and then try different technicues of meditaion 
and calming technicues to lower my heart rate for short periods of time.


My first tthought was a frequency to voltage IC like the LM2907 or the 
2917 but I get the impresiion from the data sheets that these chips will 
not work at these very low  1 Hz applications,


Then I thought maybe one of the frequecy counters could be configured as a 
rate meter and output a proportional voltage I need.

No luck here either.
Te latter components seem tobe somewhat time relatedand that is why I 
posted here.\\


Thank you for reading this and for any suggestions you folks might offer.

PaulC
W1VLF









1Hxz
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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Tom Van Baak (lab)]

Paul,

I use a picPET (http://leapsecond.com/pic/) to measure heart rate and 
stability; the original 1PPS...  The idea is simply to time-stamp every beat 
and then convert that raw data to rate or period or moving average rate, etc. 

/tvb (iPhone4) LA

On Feb 19, 2013, at 4:58 PM, Paul Cianciolo  wrote:

> Hello Folks,
>  
> I am working on a project intended to convert an analog ECG signal to a 
> voltage proportional the heart rate,
> The actual electrodes instrumentation amp is pretty much working fine  so no 
> worries there.
>  
> The problem is, and here is where the relationship to time nut comes in.
> The signal output from the instrumentation amplifiers will be at a rate of 
> approx 60 BPM or pulses, up to perhaps 90 BPM.
>  
> The purpose of this apparatus is to print a rolling chart on the screen of a 
> computer of heart BPM and then try different technicues of meditaion  and 
> calming technicues to lower my heart rate for short periods of time.
>  
> My first tthought was a frequency to voltage IC like the LM2907 or the 2917 
> but I get the impresiion from the data sheets that these chips will not work 
> at these very low  1 Hz applications,
>  
> Then I thought maybe one of the frequecy counters could be configured as a 
> rate meter and output a proportional voltage I need.
> No luck here either. 
> Te latter components seem tobe somewhat time relatedand that is why I posted 
> here.\\
>  
> Thank you for reading this and for any suggestions you folks might offer.
>  
> PaulC
> W1VLF
>  
>  
>  
>  
>  
>  
>  
>  
>  
> 1Hxz
> ___
> time-nuts mailing list -- time-nuts@febo.com
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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Hal Murray]

pa...@snet.net said:
> The actual electrodes instrumentation amp is pretty much working fine  so no
> worries there. 

> My first tthought was a frequency to voltage IC like the LM2907 or the 2917
> but I get the impresiion from the data sheets that these chips will not work
> at these very low 1 Hz applications, 

If you have clean pulses, connect them up to the PPS input on a PC serial 
port.  The rest is software.


-- 
These are my opinions.  I hate spam.



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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Bob Camp]

Hi

The first layer to the onion is that the ECG signal is a bit complex. There's 
also likely to be a bit of this and that on it. 

How about taking the output of the instrument amp into the A/D port on a cheap 
PIC? That would let you do some AGC and dynamic filtering. At even a modest 
sample rate (say 10 KHz) the heart rate could be worked out in software. I 
think I'd run a PWM out and drive an analog meter with it. 

The nice thing about keeping it simple is being able to run it off a 9 volt 
battery. That takes care of a *lot* of issues.

Bob

On Feb 19, 2013, at 7:58 PM, Paul Cianciolo  wrote:

> Hello Folks,
>  
> I am working on a project intended to convert an analog ECG signal to a 
> voltage proportional the heart rate,
> The actual electrodes instrumentation amp is pretty much working fine  so no 
> worries there.
>  
> The problem is, and here is where the relationship to time nut comes in.
> The signal output from the instrumentation amplifiers will be at a rate of 
> approx 60 BPM or pulses, up to perhaps 90 BPM.
>  
> The purpose of this apparatus is to print a rolling chart on the screen of a 
> computer of heart BPM and then try different technicues of meditaion  and 
> calming technicues to lower my heart rate for short periods of time.
>  
> My first tthought was a frequency to voltage IC like the LM2907 or the 2917 
> but I get the impresiion from the data sheets that these chips will not work 
> at these very low  1 Hz applications,
>  
> Then I thought maybe one of the frequecy counters could be configured as a 
> rate meter and output a proportional voltage I need.
> No luck here either. 
> Te latter components seem tobe somewhat time relatedand that is why I posted 
> here.\\
>  
> Thank you for reading this and for any suggestions you folks might offer.
>  
> PaulC
> W1VLF
>  
>  
>  
>  
>  
>  
>  
>  
>  
> 1Hxz
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Re: [time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Herbert Poetzl]

On Tue, Feb 19, 2013 at 04:58:04PM -0800, Paul Cianciolo wrote:
> Hello Folks,

First, I cannot speak for the list, as I'm quite new here,
but in general 'Thread Hijacking' is frowned upon :)
(read: start your own thread :)

> I am working on a project intended to convert an analog ECG
> signal to a voltage proportional the heart rate, The actual
> electrodes instrumentation amp is pretty much working fine 
> so no worries there.

> The problem is, and here is where the relationship to time nut
> comes in. The signal output from the instrumentation amplifiers
> will be at a rate of approx 60 BPM or pulses, up to perhaps 90
> BPM.  

> The purpose of this apparatus is to print a rolling chart on
> the screen of a computer of heart BPM and then try different
> technicues of meditaion  and calming technicues to lower my
> heart rate for short periods of time.

That doesn't sound to me like you would actually need a
Voltage, i.e. some other Information from which you can
deduce the current BPM would be fine as well ...

> My first tthought was a frequency to voltage IC like the
> LM2907 or the 2917 but I get the impresiion from the data
> sheets that these chips will not work at these very low 1Hz
> applications,

> Then I thought maybe one of the frequecy counters could be
> configured as a rate meter and output a proportional voltage
> I need.

I wouldn't count the frequency directly, instead, I'd
simply count the intervals, with a counter running at
a known frequency, for example, with a 1kHz or maybe 1MHz
clock, which can be easily done with a $1 microprocessor
The 'counts' for each interval are inverse proportional
to the current BPM, with some averaging you should get
a reasonable result to display on screen.

> No luck here either. 
> Te latter components seem tobe somewhat time relatedand that
> is why I posted here.\\

> Thank you for reading this and for any suggestions you folks might offer.

HTH,
Herbert

> PaulC
> W1VLF

> 1Hxz
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[time-nuts] Off topic project sort of heart rate monitor NEED BEATS PRE MINUTE TO ANALOG VOLTAGE

[Paul Cianciolo]

Hello Folks,
 
I am working on a project intended to convert an analog ECG signal to a voltage 
proportional the heart rate,
The actual electrodes instrumentation amp is pretty much working fine  so no 
worries there.
 
The problem is, and here is where the relationship to time nut comes in.
The signal output from the instrumentation amplifiers will be at a rate of 
approx 60 BPM or pulses, up to perhaps 90 BPM.
 
The purpose of this apparatus is to print a rolling chart on the screen of a 
computer of heart BPM and then try different technicues of meditaion  and 
calming technicues to lower my heart rate for short periods of time.
 
My first tthought was a frequency to voltage IC like the LM2907 or the 2917 but 
I get the impresiion from the data sheets that these chips will not work at 
these very low  1 Hz applications,
 
Then I thought maybe one of the frequecy counters could be configured as a rate 
meter and output a proportional voltage I need.
No luck here either. 
Te latter components seem tobe somewhat time relatedand that is why I posted 
here.\\
 
Thank you for reading this and for any suggestions you folks might offer.
 
PaulC
W1VLF
 
 
 
 
 
 
 
 
 
1Hxz
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Re: [time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[J. Forster]

A desk clock is more like it.

-John




> Totally agree. But the old HPs were a lot nicer looking for the $$
> Still have not figured out how you would use one of those as a wrist
> watch.
>
> On Tue, Feb 19, 2013 at 5:12 PM, J. Forster  wrote:
>
>> Paul,
>>
>> I doubt Patek makes ANYTHING a mere mortal would call 'cheap'.
>>
>> YMMV,
>>
>> -John
>>
>> =
>>
>>
>> > Actually I guess I do have a further comment. These Pateks look cheap
>> > compared to the old hp5060 24 hour clock versions.
>> >
>> > On Tue, Feb 19, 2013 at 1:23 PM, Brooke Clarke 
>> wrote:
>> >
>> >> Hi Peter:
>> >>
>> >> He's also got a larger system at item No. 140912029500 that needs
>> some
>> >> work, see the video at the bottom of each auction.
>> >>
>> >> http://www.youtube.com/watch?**feature=player_embedded&v=**Vnqy99Kowcs<
>> http://www.youtube.com/watch?feature=player_embedded&v=Vnqy99Kowcs>
>> >> http://www.youtube.com/watch?**v=siLG4fjSg3s&list=**
>> >> UUzyU78k95mbYA-hZQZCMYIQ<
>> http://www.youtube.com/watch?v=siLG4fjSg3s&list=UUzyU78k95mbYA-hZQZCMYIQ>
>> >>
>> >> Have Fun,
>> >>
>> >> Brooke Clarke
>> >> http://www.PRC68.com
>> >> http://www.**end2partygovernment.com/**2012Issues.html<
>> http://www.end2partygovernment.com/2012Issues.html>
>> >>
>> >>
>> >> Peter Vince wrote:
>> >>
>> >>> On our favourite auction site is the pulse clock system used at the
>> >>> BBC's old World Service Radio headquarters, Bush House, in London,
>> >>> including a lot of units with Patek Philippe clocks!  See ebay item
>> >>> number 140912029728.
>> >>>
>> >>> I have no connection with this item, just thought some rich member
>> of
>> >>> the group might be interested in giving it a good, loving home :-)
>> >>>
>> >>>   TTFN,
>> >>>
>> >>>Peter Vince  (London, England)
>> >>> __**_
>> >>> time-nuts mailing list -- time-nuts@febo.com
>> >>> To unsubscribe, go to https://www.febo.com/cgi-bin/**
>> >>> mailman/listinfo/time-nuts<
>> 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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>> >> mailman/listinfo/time-nuts<
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>> >> and follow the instructions there.
>> >>
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>> >
>>
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Re: [time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[paul swed]

Totally agree. But the old HPs were a lot nicer looking for the $$
Still have not figured out how you would use one of those as a wrist watch.

On Tue, Feb 19, 2013 at 5:12 PM, J. Forster  wrote:

> Paul,
>
> I doubt Patek makes ANYTHING a mere mortal would call 'cheap'.
>
> YMMV,
>
> -John
>
> =
>
>
> > Actually I guess I do have a further comment. These Pateks look cheap
> > compared to the old hp5060 24 hour clock versions.
> >
> > On Tue, Feb 19, 2013 at 1:23 PM, Brooke Clarke 
> wrote:
> >
> >> Hi Peter:
> >>
> >> He's also got a larger system at item No. 140912029500 that needs some
> >> work, see the video at the bottom of each auction.
> >>
> >> http://www.youtube.com/watch?**feature=player_embedded&v=**Vnqy99Kowcs<
> http://www.youtube.com/watch?feature=player_embedded&v=Vnqy99Kowcs>
> >> http://www.youtube.com/watch?**v=siLG4fjSg3s&list=**
> >> UUzyU78k95mbYA-hZQZCMYIQ<
> http://www.youtube.com/watch?v=siLG4fjSg3s&list=UUzyU78k95mbYA-hZQZCMYIQ>
> >>
> >> Have Fun,
> >>
> >> Brooke Clarke
> >> http://www.PRC68.com
> >> http://www.**end2partygovernment.com/**2012Issues.html<
> http://www.end2partygovernment.com/2012Issues.html>
> >>
> >>
> >> Peter Vince wrote:
> >>
> >>> On our favourite auction site is the pulse clock system used at the
> >>> BBC's old World Service Radio headquarters, Bush House, in London,
> >>> including a lot of units with Patek Philippe clocks!  See ebay item
> >>> number 140912029728.
> >>>
> >>> I have no connection with this item, just thought some rich member of
> >>> the group might be interested in giving it a good, loving home :-)
> >>>
> >>>   TTFN,
> >>>
> >>>Peter Vince  (London, England)
> >>> __**_
> >>> time-nuts mailing list -- time-nuts@febo.com
> >>> To unsubscribe, go to https://www.febo.com/cgi-bin/**
> >>> mailman/listinfo/time-nuts<
> 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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> >> mailman/listinfo/time-nuts<
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
> >> and follow the instructions there.
> >>
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> >
>
>
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Re: [time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[J. Forster]

Paul,

I doubt Patek makes ANYTHING a mere mortal would call 'cheap'.

YMMV,

-John

=


> Actually I guess I do have a further comment. These Pateks look cheap
> compared to the old hp5060 24 hour clock versions.
>
> On Tue, Feb 19, 2013 at 1:23 PM, Brooke Clarke  wrote:
>
>> Hi Peter:
>>
>> He's also got a larger system at item No. 140912029500 that needs some
>> work, see the video at the bottom of each auction.
>>
>> http://www.youtube.com/watch?**feature=player_embedded&v=**Vnqy99Kowcs
>> http://www.youtube.com/watch?**v=siLG4fjSg3s&list=**
>> UUzyU78k95mbYA-hZQZCMYIQ
>>
>> Have Fun,
>>
>> Brooke Clarke
>> http://www.PRC68.com
>> http://www.**end2partygovernment.com/**2012Issues.html
>>
>>
>> Peter Vince wrote:
>>
>>> On our favourite auction site is the pulse clock system used at the
>>> BBC's old World Service Radio headquarters, Bush House, in London,
>>> including a lot of units with Patek Philippe clocks!  See ebay item
>>> number 140912029728.
>>>
>>> I have no connection with this item, just thought some rich member of
>>> the group might be interested in giving it a good, loving home :-)
>>>
>>>   TTFN,
>>>
>>>Peter Vince  (London, England)
>>> __**_
>>> 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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>> mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
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[time-nuts] [Fwd: [TestEquipTrader] FTS-4060 Cesium Time and Frequency Standard]

[J. Forster]

FYI, from another list. Contact OP directly, not me.

-John

===



 Original Message 
Subject: [TestEquipTrader] FTS-4060 Cesium Time and Frequency Standard
From:"Chris Howard w0ep" 
Date:Tue, February 19, 2013 10:37 am
To:  testequiptra...@yahoogroups.com
--


For Sale

FTS-4060 Cesium Time and Frequency Standard

Appears to work fine, powers up and locks.
Can provide pictures and provenance info on request.

Asking $2500 or best offer.

Location:  Columbus, Mississippi
Willing to cooperate with pick-up or meeting as best I can.
Maybe a trip to Dayton?

Chris Howard
w0ep
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Re: [time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[paul swed]

Actually I guess I do have a further comment. These Pateks look cheap
compared to the old hp5060 24 hour clock versions.

On Tue, Feb 19, 2013 at 1:23 PM, Brooke Clarke  wrote:

> Hi Peter:
>
> He's also got a larger system at item No. 140912029500 that needs some
> work, see the video at the bottom of each auction.
>
> http://www.youtube.com/watch?**feature=player_embedded&v=**Vnqy99Kowcs
> http://www.youtube.com/watch?**v=siLG4fjSg3s&list=**
> UUzyU78k95mbYA-hZQZCMYIQ
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.**end2partygovernment.com/**2012Issues.html
>
>
> Peter Vince wrote:
>
>> On our favourite auction site is the pulse clock system used at the
>> BBC's old World Service Radio headquarters, Bush House, in London,
>> including a lot of units with Patek Philippe clocks!  See ebay item
>> number 140912029728.
>>
>> I have no connection with this item, just thought some rich member of
>> the group might be interested in giving it a good, loving home :-)
>>
>>   TTFN,
>>
>>Peter Vince  (London, England)
>> __**_
>> 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
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>
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Re: [time-nuts] repairing General Technology (Tracor) 304-B rubidium standard

[Magnus Danielson]

On 19/02/13 19:36, Ed Palmer wrote:

Hi Stu,

Did you find the long message threads from April & May of last year
where I was trying to fix my 304-B? Look for "Antique Rubidium
Standard", "General Technology Corp model 304b" and "Antique Rb
Standard". Lots of good info from guys like Magnus Danielson, Paul Swed,
Ed Breya and others.

To cut to the chase, no I haven't got it working. The second harmonic is
still missing. I haven't given up. I still have a few puzzles to work
out. I work on it for awhile, decide I need more equipment, wait for it
to show up on the auction site, wait for it to be delivered, fix it
and/or learn about it, make some measurements, get frustrated and walk
away for awhile, repeat until wallet is empty and workshop is full. :-)

Answers to your current questions are interspersed below. We'll talk
more, but it's probably best if we take it offlist. I'll contact you
directly.

On 2/19/2013 12:36 AM, Stewart Cobb wrote:

Guys,

I'm repairing a 1960's vintage lab-grade rubidium standard, General
Technology Corporation model 304-B. Apparently Tracor bought GTC soon
after this unit was made, because references to this as a "Tracor 304-B"
seem to be more common. I've made some progress, but now it seems like
time to consult the hive mind.

The unit appears clean, but it doesn't lock. I've read through old
comments on the list regarding this unit, and I've downloaded a copy
of the
manual and schematics available at

<*http://sundry.i2phd.com/ServiceManual_304b.pdf>*

That file seems to contain a complete copy of the manual text, but some
schematics are missing. In particular, the schematics for the
sweep/acquisition board (A8) and the three boards inside the physics
package (the lamp oscillator (A13), the SRD driver (A12), and the
photocell
preamp (A11)) are not shown. Does anyone know where to find copies of
those schematics?


I have a hard copy of the manual. I'll scan those schematics and send
them to you.


Could you put them on a suitable server?


A frequency counter (GPSDO reference) shows that the crystal oven
warms up
as expected. The output can be centered on 5 MHz and the sweep circuit
covers a symmetrical range around 5 MHz as expected.


Really? That surprises me. Drift in the OCXO should have caused an issue
over this much time. On my unit, some kind soul adjusted the oscillator
via the adjustment on the oscillator itself. Unfortunately, that changes
the oven temperature which does change the frequency, but it also moves
the oscillator away from the crystal's turnover point. It still works,
but for proper operation, the oscillator has to be opened and components
changed to bring the oscillator back to it's proper frequency at the
proper temperature.


The ovens for the
lamp and filter cell appear to warm up properly as well, judging from
test
points available on the A1 oven controller board. The test point voltages
don't quite match the ones in the PDF manual, but it looks like those
readings were typed into each individual manual after being read off the
particular unit that came with that manual.


That's one of the remaining puzzles on my unit. It appears that one of
the thermistors on my unit has drifted badly and the RF cavity (and
therefore the resonance cell) are running about 20C colder than they
should. My next round of testing will investigate that.


That would indeed help to keep the Rb-85 and Rb-87 peaks misaligned, 
with weak return signal as result.



The test point on the A5 board shows that 155 Hz resonance detector
modulation is within spec. The A6 filter-amplifier board test points show
the system attempting (and failing) to detect 155 Hz and 310 Hz resonance
signals coming back from the photocell.

The manual says that the A7 RF pre-driver board (the x14 multiplier)
should
be supplying 70 MHz at +13 dBm to the SRD driver inside the physics
package. That would be about 2.8Vpp, assuming a 50-ohm system. Instead,
it's supplying a clean 70 MHz at about 100mV into a 50-ohm load. My best
guess is that the final amplifier transistor on that board is blown,
possibly from being operated with only a scope probe as a load (infinite
VSWR). Replacement transistors are on order. Any other thoughts?


I've measured my A7 output at +12 dBm. I've also found that the level
isn't critical. Levels as low as +5 dBm didn't reduce the amplitude of
the error signal.


Once sufficient, levels should be set somewhat below peaking, and 
preferably for best stability. Signal level shift causes frequency 
shift. It's a bit obscure actually. Anyway, if you can have a servo-loop 
to maintain a stable level over time, it will reduce the drift.



Any other comments on how to get this box working again?


Invest copious amounts of time, money, and frustration. Odds of success
are unknown, but probably not great. The effort will either keep you out
of the bar or drive you to it. But you will learn lots about how a Rb
standard works! ;-)


Indeed. You guys are lucky, on one of my rubidium

Re: [time-nuts] repairing General Technology (Tracor) 304-B rubidium standard

[Ed Palmer]

Hi Stu,

Did you find the long message threads from April & May of last year 
where I was trying to fix my 304-B?  Look for "Antique Rubidium 
Standard", "General Technology Corp model 304b" and "Antique Rb 
Standard".  Lots of good info from guys like Magnus Danielson, Paul 
Swed, Ed Breya and others.


To cut to the chase, no I haven't got it working.  The second harmonic 
is still missing.  I haven't given up.  I still have a few puzzles to 
work out.  I work on it for awhile, decide I need more equipment, wait 
for it to show up on the auction site, wait for it to be delivered, fix 
it and/or learn about it, make some measurements, get frustrated and 
walk away for awhile, repeat until wallet is empty and workshop is 
full.  :-)


Answers to your current questions are interspersed below.  We'll talk 
more, but it's probably best if we take it offlist.  I'll contact you 
directly.


On 2/19/2013 12:36 AM, Stewart Cobb wrote:

Guys,

I'm repairing a 1960's vintage lab-grade rubidium standard, General
Technology Corporation model 304-B.  Apparently Tracor bought GTC soon
after this unit was made, because references to this as a "Tracor 304-B"
seem to be more common.  I've made some progress, but now it seems like
time to consult the hive mind.

The unit appears clean, but it doesn't lock.  I've read through old
comments on the list regarding this unit, and I've downloaded a copy of the
manual and schematics available at

<*http://sundry.i2phd.com/ServiceManual_304b.pdf>*

That file seems to contain a complete copy of the manual text, but some
schematics are missing.  In particular, the schematics for the
sweep/acquisition board (A8) and the three boards inside the physics
package (the lamp oscillator (A13), the SRD driver (A12), and the photocell
preamp (A11)) are not shown.  Does anyone know where to find copies of
those schematics?


I have a hard copy of the manual.  I'll scan those schematics and send 
them to you.



The main power supply voltage on my unit seems to have been deliberately
adjusted lower than spec (18.54 V actual, versus 20 +/- 0.1V specified in
the manual).  Replacing a resistor on the regulator board (that had smoked
from overload due to the low voltage) didn't change the voltage much.  I
had to crank the trimmer across half of its range to get the voltage back
within spec.  Nothing in the regulator circuitry seemed to have drifted
enough to change the setpoint that much.  Is there a reason why a tech
would have deliberately set this voltage lower than spec, or did it just
drift down over the years?


I can't think why the voltage would be intentionally adjusted down. 
Probably just drift.



A frequency counter (GPSDO reference) shows that the crystal oven warms up
as expected.  The output can be centered on 5 MHz and the sweep circuit
covers a symmetrical range around 5 MHz as expected.


Really?  That surprises me.  Drift in the OCXO should have caused an 
issue over this much time.  On my unit, some kind soul adjusted the 
oscillator via the adjustment on the oscillator itself. Unfortunately, 
that changes the oven temperature which does change the frequency, but 
it also moves the oscillator away from the crystal's turnover point.  It 
still works, but for proper operation, the oscillator has to be opened 
and components changed to bring the oscillator back to it's proper 
frequency at the proper temperature.



The ovens for the
lamp and filter cell appear to warm up properly as well, judging from test
points available on the A1 oven controller board.  The test point voltages
don't quite match the ones in the PDF manual, but it looks like those
readings were typed into each individual manual after being read off the
particular unit that came with that manual.


That's one of the remaining puzzles on my unit.  It appears that one of 
the thermistors on my unit has drifted badly and the RF cavity (and 
therefore the resonance cell) are running about 20C colder than they 
should.  My next round of testing will investigate that.



The test point on the A5 board shows that 155 Hz resonance detector
modulation is within spec.  The A6 filter-amplifier board test points show
the system attempting (and failing) to detect 155 Hz and 310 Hz resonance
signals coming back from the photocell.

The manual says that the A7 RF pre-driver board (the x14 multiplier) should
be supplying 70 MHz at +13 dBm to the SRD driver inside the physics
package.  That would be about 2.8Vpp, assuming a 50-ohm system.  Instead,
it's supplying a clean 70 MHz at about 100mV into a 50-ohm load.  My best
guess is that the final amplifier transistor on that board is blown,
possibly from being operated with only a scope probe as a load (infinite
VSWR).  Replacement transistors are on order.  Any other thoughts?


I've measured my A7 output at +12 dBm.  I've also found that the level 
isn't critical.  Levels as low as +5 dBm didn't reduce the amplitude of 
the error signal.



Obviously, the box won't lock until the

Re: [time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[Brooke Clarke]

Hi Peter:

He's also got a larger system at item No. 140912029500 that needs some work, 
see the video at the bottom of each auction.

http://www.youtube.com/watch?feature=player_embedded&v=Vnqy99Kowcs
http://www.youtube.com/watch?v=siLG4fjSg3s&list=UUzyU78k95mbYA-hZQZCMYIQ

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

Peter Vince wrote:

On our favourite auction site is the pulse clock system used at the
BBC's old World Service Radio headquarters, Bush House, in London,
including a lot of units with Patek Philippe clocks!  See ebay item
number 140912029728.

I have no connection with this item, just thought some rich member of
the group might be interested in giving it a good, loving home :-)

  TTFN,

   Peter Vince  (London, England)
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Re: [time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[paul swed]

Nice though will have to pass today.
Regards
Paul
WB8TSL

On Tue, Feb 19, 2013 at 11:10 AM, Peter Vince  wrote:

> On our favourite auction site is the pulse clock system used at the
> BBC's old World Service Radio headquarters, Bush House, in London,
> including a lot of units with Patek Philippe clocks!  See ebay item
> number 140912029728.
>
> I have no connection with this item, just thought some rich member of
> the group might be interested in giving it a good, loving home :-)
>
>  TTFN,
>
>   Peter Vince  (London, England)
> ___
> 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] Future of UTC 2013

[Steve Allen]

On Mon 2013-02-18T21:48:55 -0800, DaveH hath writ:
> > Full details of the upcoming meeting are available via
> > http://futureofutc.org/

> Love the graphic on the website.
>
> The use of a Foucault Pendulum with Earth as the bob is inspired...

Credit for the graphic goes to Pete Marenfeld at NOAO, a graphic
artist with amazing talents.  If it evokes the tension that has lasted
for the past decade between the nations whose delegates have been
arguing "you must abandon leap seconds in UTC" and the nations whose
delegates have been responding "we won't abandon leap seconds in UTC"
then it has done its job.

Our hope for the meeting is to get beyond the standoff and contribute
solid technical details about what should be behind those arguments,
what is possible, what is needed to resolve the situation.

--
Steve Allen WGS-84 (GPS)
UCO/Lick Observatory--ISB   Natural Sciences II, Room 165Lat  +36.99855
1156 High StreetVoice: +1 831 459 3046   Lng -122.06015
Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m
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[time-nuts] BBC Bush House Patek Phillipe clock system on ebay

[Peter Vince]

On our favourite auction site is the pulse clock system used at the
BBC's old World Service Radio headquarters, Bush House, in London,
including a lot of units with Patek Philippe clocks!  See ebay item
number 140912029728.

I have no connection with this item, just thought some rich member of
the group might be interested in giving it a good, loving home :-)

 TTFN,

  Peter Vince  (London, England)
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Re: [time-nuts] repairing General Technology (Tracor) 304-B rubidiumstandard

[Bob Camp]

Hi

Of course, depending on the age of an Efratom lamp - it's also missing the
Teflon. I've certainly replaced enough of them. Since it's a combo gas lamp,
you can get away without all of the stuff in the 304 when you do the
replacement. 

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of cdel...@juno.com
Sent: Tuesday, February 19, 2013 11:56 AM
To: time-nuts@febo.com
Subject: [time-nuts] repairing General Technology (Tracor) 304-B
rubidiumstandard



Stewart,

Tracor units use a high voltage pulse to start the lamp. You should be
able to hear the  relay that drives the pulse "clicking" around every 10
seconds or so until the lamp lights up.

Tracor lamp failures are  not rejuvinatable (is that really a word).
However I have in the past installed Efratom lamps into some 304D units.

Corby
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[time-nuts] repairing General Technology (Tracor) 304-B rubidium standard

[cdelect]

Stewart,

Tracor units use a high voltage pulse to start the lamp. You should be
able to hear the  relay that drives the pulse "clicking" around every 10
seconds or so until the lamp lights up.

Tracor lamp failures are  not rejuvinatable (is that really a word).
However I have in the past installed Efratom lamps into some 304D units.

Corby
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Re: [time-nuts] repairing General Technology (Tracor) 304-B rubidium standard

[Bob Camp]

Hi

Keep in mind that the Tracor's came out before the Teflon coated bulbs. Without 
the Teflon, the Rb will combine with the glass of the bulb. The ones I have 
seen slowly turn a black. As they darken, the light transmission drops enough 
to stop the standard. Since it's a chemical reaction, there is no simple way to 
reverse it.

Bob
   
On Feb 19, 2013, at 1:36 AM, Stewart Cobb  wrote:

> Guys,
> 
> I'm repairing a 1960's vintage lab-grade rubidium standard, General
> Technology Corporation model 304-B.  Apparently Tracor bought GTC soon
> after this unit was made, because references to this as a "Tracor 304-B"
> seem to be more common.  I've made some progress, but now it seems like
> time to consult the hive mind.
> 
> The unit appears clean, but it doesn't lock.  I've read through old
> comments on the list regarding this unit, and I've downloaded a copy of the
> manual and schematics available at
> 
> <*http://sundry.i2phd.com/ServiceManual_304b.pdf>*
> 
> That file seems to contain a complete copy of the manual text, but some
> schematics are missing.  In particular, the schematics for the
> sweep/acquisition board (A8) and the three boards inside the physics
> package (the lamp oscillator (A13), the SRD driver (A12), and the photocell
> preamp (A11)) are not shown.  Does anyone know where to find copies of
> those schematics?
> 
> The main power supply voltage on my unit seems to have been deliberately
> adjusted lower than spec (18.54 V actual, versus 20 +/- 0.1V specified in
> the manual).  Replacing a resistor on the regulator board (that had smoked
> from overload due to the low voltage) didn't change the voltage much.  I
> had to crank the trimmer across half of its range to get the voltage back
> within spec.  Nothing in the regulator circuitry seemed to have drifted
> enough to change the setpoint that much.  Is there a reason why a tech
> would have deliberately set this voltage lower than spec, or did it just
> drift down over the years?
> 
> A frequency counter (GPSDO reference) shows that the crystal oven warms up
> as expected.  The output can be centered on 5 MHz and the sweep circuit
> covers a symmetrical range around 5 MHz as expected.  The ovens for the
> lamp and filter cell appear to warm up properly as well, judging from test
> points available on the A1 oven controller board.  The test point voltages
> don't quite match the ones in the PDF manual, but it looks like those
> readings were typed into each individual manual after being read off the
> particular unit that came with that manual.
> 
> The test point on the A5 board shows that 155 Hz resonance detector
> modulation is within spec.  The A6 filter-amplifier board test points show
> the system attempting (and failing) to detect 155 Hz and 310 Hz resonance
> signals coming back from the photocell.
> 
> The manual says that the A7 RF pre-driver board (the x14 multiplier) should
> be supplying 70 MHz at +13 dBm to the SRD driver inside the physics
> package.  That would be about 2.8Vpp, assuming a 50-ohm system.  Instead,
> it's supplying a clean 70 MHz at about 100mV into a 50-ohm load.  My best
> guess is that the final amplifier transistor on that board is blown,
> possibly from being operated with only a scope probe as a load (infinite
> VSWR).  Replacement transistors are on order.  Any other thoughts?
> 
> Obviously, the box won't lock until the RF input is the right level.  But
> it also requires the Rb lamp to light.  Corby Dawson posted to the list
> back on 12 November 2009:
> 
> "Tracor bulbs fail with a different mechanism and last maybe 10 years."
> 
> Anyone know what that "different" failure mechanism is?  Is it repairable
> in an ordinary lab, like the heat-gun trick for LPRO bulbs?  If not, is it
> feasible to build a "Frankenstein" replacement using something like an LPRO
> or FEI bulb?
> 
> Is it possible to tell whether the lamp is lit without opening the physics
> package?  If not, are there any tricks to opening the physics package?  Any
> precautions to take before doing so?
> 
> Any other comments on how to get this box working again?
> 
> Cheers!
> --Stu
> 
> Side note:  This unit was built during the era of "elastic seconds"
> (roughly, the 1960's).  It contains a board (A9) which digitally offsets
> the output frequency in increments of roughly 7E-10, without changing the
> rubidium resonance frequency or the C-field.  There's also a note in the
> manual saying that annual changes to the definition of the second may
> require replacing the rubidium resonance cell in the physics package with a
> new cell calibrated for the new second in the new year.  Leap seconds bring
> their own problems, but compared to dismantling your lab instruments every
> year, they're a breeze.
> ___
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Re: [time-nuts] repairing General Technology (Tracor) 304-B rubidium standard

[Magnus Danielson]

On 19/02/13 07:36, Stewart Cobb wrote:

Guys,

I'm repairing a 1960's vintage lab-grade rubidium standard, General
Technology Corporation model 304-B.  Apparently Tracor bought GTC soon
after this unit was made, because references to this as a "Tracor 304-B"
seem to be more common.  I've made some progress, but now it seems like
time to consult the hive mind.

The unit appears clean, but it doesn't lock.  I've read through old
comments on the list regarding this unit, and I've downloaded a copy of the
manual and schematics available at

<*http://sundry.i2phd.com/ServiceManual_304b.pdf>*

That file seems to contain a complete copy of the manual text, but some
schematics are missing.  In particular, the schematics for the
sweep/acquisition board (A8) and the three boards inside the physics
package (the lamp oscillator (A13), the SRD driver (A12), and the photocell
preamp (A11)) are not shown.  Does anyone know where to find copies of
those schematics?

The main power supply voltage on my unit seems to have been deliberately
adjusted lower than spec (18.54 V actual, versus 20 +/- 0.1V specified in
the manual).  Replacing a resistor on the regulator board (that had smoked
from overload due to the low voltage) didn't change the voltage much.  I
had to crank the trimmer across half of its range to get the voltage back
within spec.  Nothing in the regulator circuitry seemed to have drifted
enough to change the setpoint that much.  Is there a reason why a tech
would have deliberately set this voltage lower than spec, or did it just
drift down over the years?

A frequency counter (GPSDO reference) shows that the crystal oven warms up
as expected.  The output can be centered on 5 MHz and the sweep circuit
covers a symmetrical range around 5 MHz as expected.  The ovens for the
lamp and filter cell appear to warm up properly as well, judging from test
points available on the A1 oven controller board.  The test point voltages
don't quite match the ones in the PDF manual, but it looks like those
readings were typed into each individual manual after being read off the
particular unit that came with that manual.

The test point on the A5 board shows that 155 Hz resonance detector
modulation is within spec.  The A6 filter-amplifier board test points show
the system attempting (and failing) to detect 155 Hz and 310 Hz resonance
signals coming back from the photocell.

The manual says that the A7 RF pre-driver board (the x14 multiplier) should
be supplying 70 MHz at +13 dBm to the SRD driver inside the physics
package.  That would be about 2.8Vpp, assuming a 50-ohm system.  Instead,
it's supplying a clean 70 MHz at about 100mV into a 50-ohm load.  My best
guess is that the final amplifier transistor on that board is blown,
possibly from being operated with only a scope probe as a load (infinite
VSWR).  Replacement transistors are on order.  Any other thoughts?


Trimming might have drifted. OK signal in? On a HP5060 (similar vintage) 
I had to start by tuning the crystal filter of the OCXO to get a strong 
5 MHz. I ended up having trouble with the multiplier board.



Obviously, the box won't lock until the RF input is the right level.  But
it also requires the Rb lamp to light.  Corby Dawson posted to the list
back on 12 November 2009:

"Tracor bulbs fail with a different mechanism and last maybe 10 years."

Anyone know what that "different" failure mechanism is?  Is it repairable
in an ordinary lab, like the heat-gun trick for LPRO bulbs?  If not, is it
feasible to build a "Frankenstein" replacement using something like an LPRO
or FEI bulb?

Is it possible to tell whether the lamp is lit without opening the physics
package?  If not, are there any tricks to opening the physics package?  Any
precautions to take before doing so?


The photodetector should detect the lamp intensity as a DC component. 
The modulation doesn't cut out much of the light, so the 155 Hz and 310 
Hz is there only when things are properly aligned.


The tricky part is that not only the frequency needs to be aligned, but 
also the temperature of the lamp with the temperature of the filter and 
resonance cell. Check the oven settings on it. The temperature alignment 
is needed to make the optical pumping align up and work well, if you 
don't too little pumping is achieved, and too few atomis is in the right 
state to later alter state with your applied signal and hence gives a 
much weaker signal.



Any other comments on how to get this box working again?


Check the return signal yourself. It could be that you have the 155 Hz 
and 310 Hz, but you need to re-align the phase of the synchronous 
detector, but this only comes after getting the 70 MHz operating again.



Cheers!
--Stu

Side note:  This unit was built during the era of "elastic seconds"
(roughly, the 1960's).  It contains a board (A9) which digitally offsets
the output frequency in increments of roughly 7E-10, without changing the
rubidium resonance frequency or the C-field.  There's also