L-

Lee - N2LEE

Wed, Oct 19, 2016 2:03 AM

First let me say this is first time I have posted to the group so go easy on me. :)
Secondly I want everyone to know that you guys make me feel so NORMAL for
wanting to use and understand accurate timing devices.

I thought there was something seriously wrong with me now I know there are others
affected with the same disease. hehe

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

I have searched every where using as many search terms as I can think of and can’t believe there is not a device that performs
this function.

I have found a couple of Epson RTC chips that might come close that 1pps but I don’t think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of money. hehe

Lee

First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously wrong with me now I know there are others affected with the same disease. hehe Now my questions. 1. Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ? I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is awful for accuracy. I have searched every where using as many search terms as I can think of and can’t believe there is not a device that performs this function. I have found a couple of Epson RTC chips that might come close that 1pps but I don’t think that corrects the 32khz just the clock time. 2. 10 Mhz Freq Standard I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff. I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money. I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? For the money it appears to offer a beginner a lot of features. Thanks and reading the daily digest of what you guys are working on. I have a feeling if I am not careful you guys could cost me a lot of money. hehe Lee

JH

Jim Harman

Wed, Oct 19, 2016 4:18 AM

Hi Lee,

It's not exactly what you asked for, but for your clock you might give this
a try, or consider using the underlying DS3231 chip directly.

https://www.adafruit.com/product/255

It is basically a much more accurate and stable than usual 32KHz
oscillator, with a TCXO that you can actually tweak programatically with a
resolution of about 0.1 ppm.

On Tue, Oct 18, 2016 at 10:03 PM, Lee - N2LEE via time-nuts <
time-nuts@febo.com> wrote:

First let me say this is first time I have posted to the group so go easy
on me. :)
Secondly I want everyone to know that you guys make me feel so NORMAL for
wanting to use and understand accurate timing devices.

I thought there was something seriously wrong with me now I know there are
others
affected with the same disease. hehe

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal
and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an
external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

I have searched every where using as many search terms as I can think of
and can’t believe there is not a device that performs
this function.

I have found a couple of Epson RTC chips that might come close that 1pps
but I don’t think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just
starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears
those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of
money. hehe

Lee

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.

--

--Jim Harman

Hi Lee, It's not exactly what you asked for, but for your clock you might give this a try, or consider using the underlying DS3231 chip directly. https://www.adafruit.com/product/255 It is basically a much more accurate and stable than usual 32KHz oscillator, with a TCXO that you can actually tweak programatically with a resolution of about 0.1 ppm. On Tue, Oct 18, 2016 at 10:03 PM, Lee - N2LEE via time-nuts < time-nuts@febo.com> wrote: > First let me say this is first time I have posted to the group so go easy > on me. :) > Secondly I want everyone to know that you guys make me feel so NORMAL for > wanting to use and understand accurate timing devices. > > I thought there was something seriously wrong with me now I know there are > others > affected with the same disease. hehe > > Now my questions. > > 1. Does anyone know of a device that will take a 1PPS GPS timing signal > and generate a 32.768 kHz sine wave output ? > I have big digital clock that uses an 8 bit micro processor and an > external 32.768 crystal. Obviously the external crystal is > awful for accuracy. > > I have searched every where using as many search terms as I can think of > and can’t believe there is not a device that performs > this function. > > I have found a couple of Epson RTC chips that might come close that 1pps > but I don’t think that corrects the 32khz just the clock time. > > 2. 10 Mhz Freq Standard > I am not in the same league as the majority of the list members and just > starting to dabble in GPSDO stuff. > I have tried to find a thunderbolt as a starting device but it appears > those are either dried up or people want too much money. > > I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? > For the money it appears to offer a beginner a lot of features. > > Thanks and reading the daily digest of what you guys are working on. > I have a feeling if I am not careful you guys could cost me a lot of > money. hehe > > > Lee > > > _______________________________________________ > 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. > -- --Jim Harman

TV

Tom Van Baak

Wed, Oct 19, 2016 4:54 AM

Hi Lee,

It's not likely you can directly multiply 1PPS up to 32 kHz, but it's easy to divide 10 MHz down to 32 kHz.
See http://leapsecond.com/pic/src/pd30.asm for a $1 PIC example.

A stand-alone 10 MHz OCXO or the simplest possible GPSDO would work for your digital clock project. Chris and Nick and many others have shared low-cost Arduino-class examples to the list over the years. Another example is the MCU-less James Miller design which uses a PLL at 10 kHz.

Contact me off-list some day when want a Trimble Thunderbolt; they are still available.

/tvb

----- Original Message -----
From: "Lee - N2LEE via time-nuts" time-nuts@febo.com
To: time-nuts@febo.com
Sent: Tuesday, October 18, 2016 7:03 PM
Subject: [time-nuts] 1PPS to 32.768 khz

First let me say this is first time I have posted to the group so go easy on me. :)
Secondly I want everyone to know that you guys make me feel so NORMAL for
wanting to use and understand accurate timing devices.

I thought there was something seriously wrong with me now I know there are others
affected with the same disease. hehe

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

I have searched every where using as many search terms as I can think of and can’t believe there is not a device that performs
this function.

I have found a couple of Epson RTC chips that might come close that 1pps but I don’t think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of money. hehe

Lee

Hi Lee, It's not likely you can directly multiply 1PPS up to 32 kHz, but it's easy to divide 10 MHz down to 32 kHz. See http://leapsecond.com/pic/src/pd30.asm for a $1 PIC example. A stand-alone 10 MHz OCXO or the simplest possible GPSDO would work for your digital clock project. Chris and Nick and many others have shared low-cost Arduino-class examples to the list over the years. Another example is the MCU-less James Miller design which uses a PLL at 10 kHz. Contact me off-list some day when want a Trimble Thunderbolt; they are still available. /tvb ----- Original Message ----- From: "Lee - N2LEE via time-nuts" <time-nuts@febo.com> To: <time-nuts@febo.com> Sent: Tuesday, October 18, 2016 7:03 PM Subject: [time-nuts] 1PPS to 32.768 khz First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously wrong with me now I know there are others affected with the same disease. hehe Now my questions. 1. Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ? I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is awful for accuracy. I have searched every where using as many search terms as I can think of and can’t believe there is not a device that performs this function. I have found a couple of Epson RTC chips that might come close that 1pps but I don’t think that corrects the 32khz just the clock time. 2. 10 Mhz Freq Standard I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff. I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money. I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? For the money it appears to offer a beginner a lot of features. Thanks and reading the daily digest of what you guys are working on. I have a feeling if I am not careful you guys could cost me a lot of money. hehe Lee

BH

Bill Hawkins

Wed, Oct 19, 2016 4:57 AM

Hi Lee,

We all had a first time posting on this list and survived it. No
problem.

You need to know more about phase locked loops. In this case, you need a
voltage controlled crystal oscillator that a simple binary divider can
take down to 1 PPS. That 1 PPS is compared to the GPS 1 PPS with a
simple flip-flop, which produces a pulse width that can be filtered to
be the control voltage for your VCXO. The resulting feedback loop causes
your VCXO to track GPS.

Now then, this is a great oversimplification of the process for getting
very low timing errors. However, human time constants for observation of
a clock do not require very low timing errors. Very few people would
notice a 50 millisecond error.

To get a useful answer from this group, you need to specify the accuracy
required. If you want picosecond errors, you are into big bucks.
Nanosecond errors are expensive but can be found on eBay. Microsecond
errors still need a good GPS receiver (not cheap). Millisecond errors
are not normally the subject of this group, although there has been a
thread on receivers barely capable of that.

Lurk and learn, grasshopper. The cost is low until you decide on the
level of accuracy you wish to reach.

Best regards,
Bill Hawkins

P.S. I was afflicted with the desire for accuracy down to the Caesium
standard level. Hydrogen masers remained beyond my means. Now I live in
an apartment in an old folks community, which required severe
downsizing. The return on investment was negative. The older I get, the
less I require precision time. YMMV.

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Lee -
N2LEE via time-nuts
Sent: Tuesday, October 18, 2016 9:03 PM
To: time-nuts@febo.com
Subject: [time-nuts] 1PPS to 32.768 khz

First let me say this is first time I have posted to the group so go
easy on me. :) Secondly I want everyone to know that you guys make me
feel so NORMAL for wanting to use and understand accurate timing
devices.

I thought there was something seriously wrong with me now I know there
are others affected with the same disease. hehe

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal
and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an
external 32.768 crystal. Obviously the external crystal is awful for
accuracy.

I have searched every where using as many search terms as I can think of
and can't believe there is not a device that performs this function.

I have found a couple of Epson RTC chips that might come close that 1pps
but I don't think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just
starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears
those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO
?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of
money. hehe

Lee

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.

Hi Lee, We all had a first time posting on this list and survived it. No problem. You need to know more about phase locked loops. In this case, you need a voltage controlled crystal oscillator that a simple binary divider can take down to 1 PPS. That 1 PPS is compared to the GPS 1 PPS with a simple flip-flop, which produces a pulse width that can be filtered to be the control voltage for your VCXO. The resulting feedback loop causes your VCXO to track GPS. Now then, this is a great oversimplification of the process for getting very low timing errors. However, human time constants for observation of a clock do not require very low timing errors. Very few people would notice a 50 millisecond error. To get a useful answer from this group, you need to specify the accuracy required. If you want picosecond errors, you are into big bucks. Nanosecond errors are expensive but can be found on eBay. Microsecond errors still need a good GPS receiver (not cheap). Millisecond errors are not normally the subject of this group, although there has been a thread on receivers barely capable of that. Lurk and learn, grasshopper. The cost is low until you decide on the level of accuracy you wish to reach. Best regards, Bill Hawkins P.S. I was afflicted with the desire for accuracy down to the Caesium standard level. Hydrogen masers remained beyond my means. Now I live in an apartment in an old folks community, which required severe downsizing. The return on investment was negative. The older I get, the less I require precision time. YMMV. -----Original Message----- From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Lee - N2LEE via time-nuts Sent: Tuesday, October 18, 2016 9:03 PM To: time-nuts@febo.com Subject: [time-nuts] 1PPS to 32.768 khz First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously wrong with me now I know there are others affected with the same disease. hehe Now my questions. 1. Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ? I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is awful for accuracy. I have searched every where using as many search terms as I can think of and can't believe there is not a device that performs this function. I have found a couple of Epson RTC chips that might come close that 1pps but I don't think that corrects the 32khz just the clock time. 2. 10 Mhz Freq Standard I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff. I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money. I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? For the money it appears to offer a beginner a lot of features. Thanks and reading the daily digest of what you guys are working on. I have a feeling if I am not careful you guys could cost me a lot of money. hehe Lee _______________________________________________ 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.

CA

Chris Albertson

Wed, Oct 19, 2016 6:26 AM

What you want is a GPSDO. Most people here build these to run at 10MHz.
But you need one that runs at 32768 kHz.

Try this: Divide the crystal oscillator's output by 32768. This will give
you one Hz. Compare the phase of this with the phase of your PPS from the
GPS. Push and pull the crystal oscillator so that the phase is locked.

The first and most critical step is to build a good 32768 Hz oscillator
that can be fine tuned by a controlling voltage. Usually a reverse biased
diode is used because the capacitance of the diode depends on the voltage
across it. You'll need a very good quality 32768 Hz voltage controlled
oscillator (VCO).

In short, go the other way around, don't try and scale up the 1PPS, scale
the 32K down to 1Hz

That said, y you really don't have to divide the 32K signal. Measure the
time from the zero crossing of the PPS to the nest zero crossing of the 32K
signal and control the VCO to keep this time constant. What you are
building isa phase locked loop

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal
and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an
external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

I have searched every where using as many search terms as I can think of
and can’t believe there is not a device that performs
this function.

I have found a couple of Epson RTC chips that might come close that 1pps
but I don’t think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just
starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears
those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of
money. hehe

Lee

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.

--

Chris Albertson
Redondo Beach, California

What you want is a GPSDO. Most people here build these to run at 10MHz. But you need one that runs at 32768 kHz. Try this: Divide the crystal oscillator's output by 32768. This will give you one Hz. Compare the phase of this with the phase of your PPS from the GPS. Push and pull the crystal oscillator so that the phase is locked. The first and most critical step is to build a good 32768 Hz oscillator that can be fine tuned by a controlling voltage. Usually a reverse biased diode is used because the capacitance of the diode depends on the voltage across it. You'll need a very good quality 32768 Hz voltage controlled oscillator (VCO). In short, go the other way around, don't try and scale up the 1PPS, scale the 32K down to 1Hz That said, y you really don't have to divide the 32K signal. Measure the time from the zero crossing of the PPS to the nest zero crossing of the 32K signal and control the VCO to keep this time constant. What you are building isa phase locked loop Now my questions. > > 1. Does anyone know of a device that will take a 1PPS GPS timing signal > and generate a 32.768 kHz sine wave output ? > I have big digital clock that uses an 8 bit micro processor and an > external 32.768 crystal. Obviously the external crystal is > awful for accuracy. > > I have searched every where using as many search terms as I can think of > and can’t believe there is not a device that performs > this function. > > I have found a couple of Epson RTC chips that might come close that 1pps > but I don’t think that corrects the 32khz just the clock time. > > 2. 10 Mhz Freq Standard > I am not in the same league as the majority of the list members and just > starting to dabble in GPSDO stuff. > I have tried to find a thunderbolt as a starting device but it appears > those are either dried up or people want too much money. > > I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? > For the money it appears to offer a beginner a lot of features. > > Thanks and reading the daily digest of what you guys are working on. > I have a feeling if I am not careful you guys could cost me a lot of > money. hehe > > > Lee > > > _______________________________________________ > 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. > -- Chris Albertson Redondo Beach, California

DB

Dave Brown

Wed, Oct 19, 2016 9:26 AM

Lee
Might be easier to run the GPSDO up at 16,384 kHz, like the E1 area telcos
used to do (and some still do)- then divide that by 500 when your done with
the PLL side of things and you have a clean stable 32.768 kHz reference to
feed into the micro in place of the xtal.
But first off, I'd be inclined to dig into the micro circuitry in the clock
and see if and where you might be able to feed in the 1 PPS instead of that
derived from the 32 kHz xtal.
DaveB, NZ

----- Original Message -----
From: "Chris Albertson" albertson.chris@gmail.com
To: "Lee - N2LEE" lee@n2lee.com; "Discussion of precise time and frequency
measurement" time-nuts@febo.com
Sent: Wednesday, October 19, 2016 7:26 PM
Subject: Re: [time-nuts] 1PPS to 32.768 khz

What you want is a GPSDO. Most people here build these to run at 10MHz.
But you need one that runs at 32768 kHz.

Try this: Divide the crystal oscillator's output by 32768. This will
give
you one Hz. Compare the phase of this with the phase of your PPS from
the
GPS. Push and pull the crystal oscillator so that the phase is locked.

The first and most critical step is to build a good 32768 Hz oscillator
that can be fine tuned by a controlling voltage. Usually a reverse
biased
diode is used because the capacitance of the diode depends on the voltage
across it. You'll need a very good quality 32768 Hz voltage controlled
oscillator (VCO).

In short, go the other way around, don't try and scale up the 1PPS, scale
the 32K down to 1Hz

That said, y you really don't have to divide the 32K signal. Measure the
time from the zero crossing of the PPS to the nest zero crossing of the
32K
signal and control the VCO to keep this time constant. What you are
building isa phase locked loop

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal
and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an
external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

I have searched every where using as many search terms as I can think of
and can’t believe there is not a device that performs
this function.

I have found a couple of Epson RTC chips that might come close that 1pps
but I don’t think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just
starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears
those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO
?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of
money. hehe

Lee

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.

--

Chris Albertson
Redondo Beach, California

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.

Lee Might be easier to run the GPSDO up at 16,384 kHz, like the E1 area telcos used to do (and some still do)- then divide that by 500 when your done with the PLL side of things and you have a clean stable 32.768 kHz reference to feed into the micro in place of the xtal. But first off, I'd be inclined to dig into the micro circuitry in the clock and see if and where you might be able to feed in the 1 PPS instead of that derived from the 32 kHz xtal. DaveB, NZ ----- Original Message ----- From: "Chris Albertson" <albertson.chris@gmail.com> To: "Lee - N2LEE" <lee@n2lee.com>; "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Wednesday, October 19, 2016 7:26 PM Subject: Re: [time-nuts] 1PPS to 32.768 khz > What you want is a GPSDO. Most people here build these to run at 10MHz. > But you need one that runs at 32768 kHz. > > Try this: Divide the crystal oscillator's output by 32768. This will > give > you one Hz. Compare the phase of this with the phase of your PPS from > the > GPS. Push and pull the crystal oscillator so that the phase is locked. > > The first and most critical step is to build a good 32768 Hz oscillator > that can be fine tuned by a controlling voltage. Usually a reverse > biased > diode is used because the capacitance of the diode depends on the voltage > across it. You'll need a very good quality 32768 Hz voltage controlled > oscillator (VCO). > > In short, go the other way around, don't try and scale up the 1PPS, scale > the 32K down to 1Hz > > That said, y you really don't have to divide the 32K signal. Measure the > time from the zero crossing of the PPS to the nest zero crossing of the > 32K > signal and control the VCO to keep this time constant. What you are > building isa phase locked loop > > > > Now my questions. >> >> 1. Does anyone know of a device that will take a 1PPS GPS timing signal >> and generate a 32.768 kHz sine wave output ? >> I have big digital clock that uses an 8 bit micro processor and an >> external 32.768 crystal. Obviously the external crystal is >> awful for accuracy. >> >> I have searched every where using as many search terms as I can think of >> and can’t believe there is not a device that performs >> this function. >> >> I have found a couple of Epson RTC chips that might come close that 1pps >> but I don’t think that corrects the 32khz just the clock time. >> >> 2. 10 Mhz Freq Standard >> I am not in the same league as the majority of the list members and just >> starting to dabble in GPSDO stuff. >> I have tried to find a thunderbolt as a starting device but it appears >> those are either dried up or people want too much money. >> >> I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO >> ? >> For the money it appears to offer a beginner a lot of features. >> >> Thanks and reading the daily digest of what you guys are working on. >> I have a feeling if I am not careful you guys could cost me a lot of >> money. hehe >> >> >> Lee >> >> >> _______________________________________________ >> 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. >> > > > > -- > > Chris Albertson > Redondo Beach, California > _______________________________________________ > 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.

DJ

David J Taylor

Wed, Oct 19, 2016 9:38 AM

First let me say this is first time I have posted to the group so go easy on
me. :)
Secondly I want everyone to know that you guys make me feel so NORMAL for
wanting to use and understand accurate timing devices.

I thought there was something seriously wrong with me now I know there are
others
affected with the same disease. hehe

Now my questions.
[]
2. 10 Mhz Freq Standard
[]
I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of money.
hehe

Lee

Lee,

I have one of the Leo Bodnar GPSDO devices and it works well, using a patch
antenna on the top floor of a building. I haven't subjected it to detailed
measurements but others here have. You can use it to drive some SDR devices
too, such as the AirSpy. Being a new device, it's fully supported, of
course, and it has two outputs (linked in frequency).

73,
David GM8ARV

SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv

First let me say this is first time I have posted to the group so go easy on me. :) Secondly I want everyone to know that you guys make me feel so NORMAL for wanting to use and understand accurate timing devices. I thought there was something seriously wrong with me now I know there are others affected with the same disease. hehe Now my questions. [] 2. 10 Mhz Freq Standard [] I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? For the money it appears to offer a beginner a lot of features. Thanks and reading the daily digest of what you guys are working on. I have a feeling if I am not careful you guys could cost me a lot of money. hehe Lee ============================== Lee, I have one of the Leo Bodnar GPSDO devices and it works well, using a patch antenna on the top floor of a building. I haven't subjected it to detailed measurements but others here have. You can use it to drive some SDR devices too, such as the AirSpy. Being a new device, it's fully supported, of course, and it has two outputs (linked in frequency). 73, David GM8ARV -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv

P

planophore@aei.ca

Wed, Oct 19, 2016 11:10 AM

Lee,

Another option might be something like this:

http://qrp-labs.com/progrock.html

it is a standalone ATTiny based device which uses a plug in Si5351a
synthesizer. Output frequencies from as low as 3.515 khz to a 100+ MHz
can programmed and can be GPS disciplined suing a GPS' PPS. There are
some limits on the PPS (i.e. very narrow will work).

Granted, phase noise and jitter in this example are a wildcard and I
couldn't comment on that with respect to your application.

The Si5351a synthesizer board uses a simple 27MHz crystal but can
replaced with a standard SMD 27MHz oscillator or TCXO. Once "burned"
in, can be very stable all on it's own and may be sufficient your needs.

cheers, Graham

On 10/19/2016, "Lee - N2LEE via time-nuts" time-nuts@febo.com wrote:

First let me say this is first time I have posted to the group so go easy on me. :)
Secondly I want everyone to know that you guys make me feel so NORMAL for
wanting to use and understand accurate timing devices.

I thought there was something seriously wrong with me now I know there are others
affected with the same disease. hehe

Now my questions.

Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

I have searched every where using as many search terms as I can think of and canât believe there is not a device that performs
this function.

I have found a couple of Epson RTC chips that might come close that 1pps but I donât think that corrects the 32khz just the clock time.

10 Mhz Freq Standard
I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff.
I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money.

I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ?
For the money it appears to offer a beginner a lot of features.

Thanks and reading the daily digest of what you guys are working on.
I have a feeling if I am not careful you guys could cost me a lot of money. hehe

Lee

Lee, Another option might be something like this: http://qrp-labs.com/progrock.html it is a standalone ATTiny based device which uses a plug in Si5351a synthesizer. Output frequencies from as low as 3.515 khz to a 100+ MHz can programmed and can be GPS disciplined suing a GPS' PPS. There are some limits on the PPS (i.e. very narrow will work). Granted, phase noise and jitter in this example are a wildcard and I couldn't comment on that with respect to your application. The Si5351a synthesizer board uses a simple 27MHz crystal but can replaced with a standard SMD 27MHz oscillator or TCXO. Once "burned" in, can be very stable all on it's own and may be sufficient your needs. cheers, Graham On 10/19/2016, "Lee - N2LEE via time-nuts" <time-nuts@febo.com> wrote: >First let me say this is first time I have posted to the group so go easy on me. :) >Secondly I want everyone to know that you guys make me feel so NORMAL for >wanting to use and understand accurate timing devices. > >I thought there was something seriously wrong with me now I know there are others >affected with the same disease. hehe > >Now my questions. > >1. Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ? >I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is >awful for accuracy. > >I have searched every where using as many search terms as I can think of and canât believe there is not a device that performs >this function. > >I have found a couple of Epson RTC chips that might come close that 1pps but I donât think that corrects the 32khz just the clock time. > >2. 10 Mhz Freq Standard >I am not in the same league as the majority of the list members and just starting to dabble in GPSDO stuff. >I have tried to find a thunderbolt as a starting device but it appears those are either dried up or people want too much money. > >I wanted to get the opinion of anyone who has tried the Leo Bodnar GPSDO ? >For the money it appears to offer a beginner a lot of features. > >Thanks and reading the daily digest of what you guys are working on. >I have a feeling if I am not careful you guys could cost me a lot of money. hehe > > >Lee >

DM

Dave Martindale

Wed, Oct 19, 2016 1:15 PM

If the "big digital clock" doesn't display the time with fractional-second
precision, then it only needs to be updated at 1 Hz, which can be done with
the 1 PPS directly. Consider replacing the 32 kHz crystal, divider chain,
and microprocessor with a new microcontroller that takes 1 Hz input and
drives the display in the same way.

For an extra bonus, use a microcontroller with a serial port, and connect
the GPS receiver serial output to the serial port on the micro. Then you
can decode the serial data stream from the GPS, and automatically set the
clock to the correct time after a power failure - something the original
clock could not do. As a double bonus, make the clock display leap seconds
correctly when they happen.

Dave

On Tue, Oct 18, 2016 at 10:03 PM, Lee - N2LEE via time-nuts <
time-nuts@febo.com> wrote:

Does anyone know of a device that will take a 1PPS GPS timing signal
and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an
external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

If the "big digital clock" doesn't display the time with fractional-second precision, then it only needs to be updated at 1 Hz, which can be done with the 1 PPS directly. Consider replacing the 32 kHz crystal, divider chain, and microprocessor with a new microcontroller that takes 1 Hz input and drives the display in the same way. For an extra bonus, use a microcontroller with a serial port, and connect the GPS receiver serial output to the serial port on the micro. Then you can decode the serial data stream from the GPS, and automatically set the clock to the correct time after a power failure - something the original clock could not do. As a double bonus, make the clock display leap seconds correctly when they happen. - Dave On Tue, Oct 18, 2016 at 10:03 PM, Lee - N2LEE via time-nuts < time-nuts@febo.com> wrote: > > 1. Does anyone know of a device that will take a 1PPS GPS timing signal > and generate a 32.768 kHz sine wave output ? > I have big digital clock that uses an 8 bit micro processor and an > external 32.768 crystal. Obviously the external crystal is > awful for accuracy. > > >

L-

Lee - N2LEE

Wed, Oct 19, 2016 2:15 PM

You guys are great. I especially like the more creative solutions that could take this project to a different level.

I should have known that my request was not a simple one. :)

While going from 1 PPS to 32.786 is not as easy as I had hoped what I find odd is that others must have been
looking for this same solution. Hard to believe an innovative chip designer has not solved this problem.

I have been able to find solutions that come close.
For example Epson /Seiko makes a RTC chip with a built in TCXO that will let you use the devices 32khz oscillator and
it allows for 1 PPS input. BUT (always a but) I don't think it corrects the oscillator just the RTC clock. (I think).

http://www5.epsondevice.com/en/products/i2c/rx8803sa.html

I have to tell you guys the recommendations I am getting are great even if they don't solve my exact solution.
The reason is you are giving me a lot to think about and research which means I am learning. I LOVE That ! :)

Keep the ideas coming and thanks for your patience.

Lee

On Oct 19, 2016, at 9:15 AM, Dave Martindale dave.martindale@gmail.com wrote:

If the "big digital clock" doesn't display the time with fractional-second precision, then it only needs to be updated at 1 Hz, which can be done with the 1 PPS directly. Consider replacing the 32 kHz crystal, divider chain, and microprocessor with a new microcontroller that takes 1 Hz input and drives the display in the same way.

For an extra bonus, use a microcontroller with a serial port, and connect the GPS receiver serial output to the serial port on the micro. Then you can decode the serial data stream from the GPS, and automatically set the clock to the correct time after a power failure - something the original clock could not do. As a double bonus, make the clock display leap seconds correctly when they happen.

Dave

On Tue, Oct 18, 2016 at 10:03 PM, Lee - N2LEE via time-nuts time-nuts@febo.com wrote:

Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ?
I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is
awful for accuracy.

You guys are great. I especially like the more creative solutions that could take this project to a different level. I should have known that my request was not a simple one. :) While going from 1 PPS to 32.786 is not as easy as I had hoped what I find odd is that others must have been looking for this same solution. Hard to believe an innovative chip designer has not solved this problem. I have been able to find solutions that come close. For example Epson /Seiko makes a RTC chip with a built in TCXO that will let you use the devices 32khz oscillator and it allows for 1 PPS input. BUT (always a but) I don't think it corrects the oscillator just the RTC clock. (I think). http://www5.epsondevice.com/en/products/i2c/rx8803sa.html I have to tell you guys the recommendations I am getting are great even if they don't solve my exact solution. The reason is you are giving me a lot to think about and research which means I am learning. I LOVE That ! :) Keep the ideas coming and thanks for your patience. Lee On Oct 19, 2016, at 9:15 AM, Dave Martindale <dave.martindale@gmail.com> wrote: > If the "big digital clock" doesn't display the time with fractional-second precision, then it only needs to be updated at 1 Hz, which can be done with the 1 PPS directly. Consider replacing the 32 kHz crystal, divider chain, and microprocessor with a new microcontroller that takes 1 Hz input and drives the display in the same way. > > For an extra bonus, use a microcontroller with a serial port, and connect the GPS receiver serial output to the serial port on the micro. Then you can decode the serial data stream from the GPS, and automatically set the clock to the correct time after a power failure - something the original clock could not do. As a double bonus, make the clock display leap seconds correctly when they happen. > > - Dave > > On Tue, Oct 18, 2016 at 10:03 PM, Lee - N2LEE via time-nuts <time-nuts@febo.com> wrote: > > 1. Does anyone know of a device that will take a 1PPS GPS timing signal and generate a 32.768 kHz sine wave output ? > I have big digital clock that uses an 8 bit micro processor and an external 32.768 crystal. Obviously the external crystal is > awful for accuracy. > >

time-nuts@lists.febo.com

1PPS to 32.768 khz

Lee

73, David GM8ARV

73,
David GM8ARV