date:20180304


n...@npgcable.com said:
> Does the oscillator have an adjustment?  If so, is this somewhat accessible
> without destroying the assembly?  Are there pictures of the oscillator
> assembly? 

https://www.realhamradio.com/GPS-oven-journey.htm

https://www.realhamradio.com/z3801a-turning-point.htm


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Re: [time-nuts] Z3801A OCXO manual trimming

Hi

> On Mar 4, 2018, at 10:30 PM, Joe Hobart  wrote:
> 
> 
> Mark,
> 
> When I press "D" Lady Heather replies:
> 
> Manual disciplining not supported by this receiverpress ESC
> 
> 
> Questions about the Z3801A:
> 
> Does the oscillator have an adjustment?  If so, is this somewhat accessible

Yes, if you dig deep enough

> without destroying the assembly?

Depends on how good you are at ripping into things 

>  Are there pictures of the oscillator assembly?

I believe there are in the archives

> 
> Is there an adjustment for temperature?

Yes, by changing the select resistor 

>  Is this accessible?

Yes, once you have the inside oven board out of the enclosure. Accessible is a 
relative term. I would not dig that deep. Others on the list seem to be happy 
going
that far into the assembly. 

Bob

> 
> Thanks,
> Joe, W7LUX
> 
> 
> Lady Heather has a command that lets you set the DAC voltage.  It's in the "D"
> menu.   Depending upon the firmware, you may need to disable disciplining 
> first
> (also in the "D" menu).  If the DAC  command works to change the OCXO freq,  
> the
> osc EFC and DAC are probably OK.  If it does not, I'd suspect the DAC or the
> osc EFC input... or perhaps your firmware does no support the DAC setting 
> command.
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Re: [time-nuts] Z3801A OCXO manual trimming

2018-03-04 Thread Joe Hobart


Mark,

When I press "D" Lady Heather replies:

Manual disciplining not supported by this receiverpress ESC


Questions about the Z3801A:

Does the oscillator have an adjustment?  If so, is this somewhat accessible
without destroying the assembly?  Are there pictures of the oscillator assembly?

Is there an adjustment for temperature?  Is this accessible?

Thanks,
Joe, W7LUX


Lady Heather has a command that lets you set the DAC voltage.  It's in the "D"
menu.   Depending upon the firmware, you may need to disable disciplining first
(also in the "D" menu).  If the DAC  command works to change the OCXO freq,  the
osc EFC and DAC are probably OK.  If it does not, I'd suspect the DAC or the
osc EFC input... or perhaps your firmware does no support the DAC setting 
command.
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Re: [time-nuts] While we are talking about Z3801's


kb...@n1k.org said:
> If still nothing, put a scope on the RX output of the serial chip in the
> 3801. Do the same  for the TX input of the same chip.  

I think the Z3801A prints out a version string at power up.  Sometimes that 
helps debug the transmit path.


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Re: [time-nuts] While we are talking about Z3801's

Hi

Basic troubleshooting: 

Check the regulator output voltages and repair as needed.

Basic serial troubleshooting:

Bring up a terminal program, loop back the serial with a jumper, see if you 
have 
a connection. 

If you do, issue basic commands, see what happens. 

Switch to likely baud rates repeat basic commands. 

If still nothing, put a scope on the RX output of the serial chip in the 3801. 
Do the same 
for the TX input of the same chip. 

…… dig on in from there. 

Bob

> On Mar 4, 2018, at 9:22 PM, Hal Murray  wrote:
> 
> 
> wpxs...@gmail.com said:
>> Hal, I can't communicate with it. That has been gone for a while now. 
> 
> I assume it worked at some point.  Did talking to it stop working at the same 
> time the frequency stopped tracking?  If so, I'd guess the CPU inside has 
> stopped working and isn't setting the DAC correctly.
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
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Re: [time-nuts] While we are talking about Z3801's


wpxs...@gmail.com said:
> Hal, I can't communicate with it. That has been gone for a while now. 

I assume it worked at some point.  Did talking to it stop working at the same 
time the frequency stopped tracking?  If so, I'd guess the CPU inside has 
stopped working and isn't setting the DAC correctly.


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Re: [time-nuts] LT1016 as a pulse shaper...

Hi

Having tried to do these measurements a lot of ways ….. the TimePod makes it 
*very*
easy. The ability to get phase noise and ADEV “all at once” is part of it. The 
ability to 
handle a wide range of input levels with minimal degradation is a also part of 
the why.
The software makes it easy for lazy Bob … a big plus ….

Bob

> On Mar 4, 2018, at 8:32 PM, Bruce Griffiths  
> wrote:
> 
> Since I have a Timepod all that I'd need would be a board that had SMA inputs 
> and outputs with provision for an LC L network to  step up the input if 
> necessary plus an RLC network on the output something like in the attachment.
> 
> If one doesnt have a Timepod or equivalent a low noise phase detector will 
> suffice for the noisier sources. An adjustable phase shift network is 
> required to achieve quadrature between the LO (driven directly from the 
> splitter) and the RF input (driven by the DUT output).
> 
> The required phase shift adjustment range could perhaps be reduced by using a 
> quadrature hybrid to split the test source instead of a standard splitter. 
> The output of the phase detector is low pass filtered and amplified and fed 
> to a high resolution ADC such as a sound card.
> 
> Bruce
> 
>> 
>>On 05 March 2018 at 13:59 Hal Murray  wrote:
>> 
>>Bruce Griffiths  said:
>> 
 
>>>If I had a suitable PCB board for it I would do the measurement 
>>> properly.
>>> 
 
>>What would a suitable board look like and/or what sort of gear do you 
>> need to
>>measure PN?
>> 
>>--
>>These are my opinions. I hate spam.
>> 
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Re: [time-nuts] LT1016 as a pulse shaper...

Since I have a Timepod all that I'd need would be a board that had SMA inputs 
and outputs with provision for an LC L network to  step up the input if 
necessary plus an RLC network on the output something like in the attachment.

If one doesnt have a Timepod or equivalent a low noise phase detector will 
suffice for the noisier sources. An adjustable phase shift network is required 
to achieve quadrature between the LO (driven directly from the splitter) and 
the RF input (driven by the DUT output).

The required phase shift adjustment range could perhaps be reduced by using a 
quadrature hybrid to split the test source instead of a standard splitter. The 
output of the phase detector is low pass filtered and amplified and fed to a 
high resolution ADC such as a sound card.

Bruce

> 
> On 05 March 2018 at 13:59 Hal Murray  wrote:
> 
> Bruce Griffiths  said:
> 
> > > 
> > If I had a suitable PCB board for it I would do the measurement 
> > properly.
> > 
> > > 
> What would a suitable board look like and/or what sort of gear do you 
> need to
> measure PN?
> 
> --
> These are my opinions. I hate spam.
> 
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Re: [time-nuts] LT1016 as a pulse shaper...

Hi

The “best” way to measure phase noise will always be a “that depends” sort of 
thing. One
pretty darn good way to check noise on any amplifier is to use something like a 
TimePod. 
You use a power splitter and a pretty good source. First you check your TImePod 
(or whatever)
for floor. You then stick the amp in one leg. You re-measure phase noise (or 
ADEV). Assuming 
it comes up above the previous floor, you have your number for the device. If 
it does not come
up above the previous floor, you need a different test set. 

Bob

> On Mar 4, 2018, at 7:59 PM, Hal Murray  wrote:
> 
> Bruce Griffiths  said:
>> If I had a suitable PCB board for it I would do the measurement properly.
> 
> What would a suitable board look like and/or what sort of gear do you need to 
> measure PN?
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
> ___
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Re: [time-nuts] LT1016 as a pulse shaper...

Bruce Griffiths  said:
> If I had a suitable PCB board for it I would do the measurement properly.

What would a suitable board look like and/or what sort of gear do you need to 
measure PN?


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Re: [time-nuts] WWV or Net Clock controlled oscillator

2018-03-04 Thread Adrian Godwin

Donald,

I'm interested to hear more about the Maas-Rowe controller. I presume
something that plays a fixed peal on the chimes ?

I found another You-tube video where someone was describing a set of
chimes, but it had a tube amplifier and a small manual keyboard. He didn't
describe any sort of automatic player, and from the age of the system I
would imagine it would have been semi-mechanical, like a player piano.


How does the controller you  are restoring operate ?


On Sun, Mar 4, 2018 at 11:11 PM, Tom Van Baak  wrote:

> Adrian, et al.
>
> An updated list of PIC dividers:
> http://leapsecond.com/pic/picdiv-list.htm
>
> Source code and hex files:
> http://leapsecond.com/pic/src/
>
> And, you guessed it, PD60 is the one that divides 10 MHz into 60 Hz
> (exactly). Documentation and source code:
> http://leapsecond.com/pic/src/pd60.asm
>
> /tvb
>
> - Original Message -
> From: "Adrian Godwin" 
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Sunday, March 04, 2018 2:57 PM
> Subject: Re: [time-nuts] WWV or Net Clock controlled oscillator
>
>
> > There is indeed a 60Hz out picdiv from Tom Van Baak -
> > http://www.leapsecond.com/pic/picdiv.htm. It's not in that list but ask
> Tom.
> >
> > I've just used one (modified for 50Hz out) to drive a 1A H-bridge circuit
> > that supplies a 12V peak-peak square wave to an old LED clock, replacing
> > the original wall-wart.
> > It works very nicely, and is driven by the 10MHz output of a cheap
> surplus
> > GPSDO.
>
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[time-nuts] Z3801A OCXO manual trimming

2018-03-04 Thread Mark Sims

Lady Heather has a command that lets you set the DAC voltage.  It's in the "D" 
menu.   Depending upon the firmware, you may need to disable disciplining first 
(also in the "D" menu).  If the DAC  command works to change the OCXO freq,  
the osc EFC and DAC are probably OK.  If it does not, I'd suspect the DAC or 
the  osc EFC input... or perhaps your firmware does no support the DAC setting 
command.
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Re: [time-nuts] WWV or Net Clock controlled oscillator

2018-03-04 Thread Tom Van Baak

Adrian, et al.

An updated list of PIC dividers:
http://leapsecond.com/pic/picdiv-list.htm

Source code and hex files:
http://leapsecond.com/pic/src/

And, you guessed it, PD60 is the one that divides 10 MHz into 60 Hz (exactly). 
Documentation and source code:
http://leapsecond.com/pic/src/pd60.asm

/tvb

- Original Message - 
From: "Adrian Godwin" 
To: "Discussion of precise time and frequency measurement" 
Sent: Sunday, March 04, 2018 2:57 PM
Subject: Re: [time-nuts] WWV or Net Clock controlled oscillator


> There is indeed a 60Hz out picdiv from Tom Van Baak -
> http://www.leapsecond.com/pic/picdiv.htm. It's not in that list but ask Tom.
> 
> I've just used one (modified for 50Hz out) to drive a 1A H-bridge circuit
> that supplies a 12V peak-peak square wave to an old LED clock, replacing
> the original wall-wart.
> It works very nicely, and is driven by the 10MHz output of a cheap surplus
> GPSDO.

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Re: [time-nuts] WWV or Net Clock controlled oscillator

2018-03-04 Thread Tom Van Baak

Donald,

Possible solutions to your 60 Hz mains problem:

1) If you don't want to open or hack the clock controller in any way consider 
using a "online" UPS. Typically the synthesized 60 Hz AC output is quartz 
controlled.

2) Make your own low-power 60 Hz AC/DC/AC power supply -- using a quartz, or 
ovenized quartz, or GPSDO or NTP-based timebase. How many watts do you need? 
How many seconds per week is your limit?

3) Open the clock controller and locate the wire that gets the 60 Hz timing; 
probably from a low voltage winding of the transformer. Then cut the wire and 
feed your own precise digital 60 Hz instead.

4) You mentioned "the 60Hz reference can be switched out". In that case what is 
the time source? What frequency? Based on a cheap quartz xtal? If so, perhaps 
it's easier to replace that instead of messing with 60 Hz.

> I was trying to locate a cost effective clock reference which can be
> synchronized from either WWV, request the correct time from a net server or
> possibly GPS.  It then needs a clock referenced output of 60Hz.

Can you be more specific about this requirement? Generating a precise 60 Hz is 
a different problem from knowing what the current local date / time is.

/tvb

- Original Message - 
From: "D. Resor" 
To: "Time Nuts List" 
Sent: Sunday, March 04, 2018 2:30 AM
Subject: [time-nuts] WWV or Net Clock controlled oscillator


> Hello,
> 
> 
> 
> My first post here. I found this group's user group page while researching a
> source for either a WWV, GPS or Network referenced oscillator.
> 
> 
> 
> The devices/equipment which I was able to find didn't  seem to fit the
> requirements.
> 
> 
> 
> What I have is a Maas-Rowe DCB1 (Digital Chronobell Series 1) clock
> controller.  
> 
> Seen here:
> http://hammondorganservice.com/downloads/images/carillon/TempleCitySDADCB1a.
> jpg
> 
> 
> 
> The system can be heard playing the Westminster Chimes and striking 12 noon
> here:
> 
> 
> 
> https://www.youtube.com/watch?v=Ij5c6RqGhn0
> 
> 
> 
> 
> 
> It can be programmed to play Westminster sequences and/or music selections
> using Maas-Rowe real struck chromatically tuned bell rods.
> 
> 
> 
> This unit is installed in Southern California Edison area.  The problem is,
> this unit receives its clock reference from the 60Hz AC line to keep it in
> sync.  Up until a few years ago this worked very well.  Now, Edison's 60Hz
> line frequency is all over the place and this clock unit now gains 30
> seconds and/or more a week which makes it difficult to keep it synchronized.
> 
> 
> 
> The 60Hz reference can be switched out by the use of dip switches, however
> that setting isn't much better.
> 
> 
> 
> I was trying to locate a cost effective clock reference which can be
> synchronized from either WWV, request the correct time from a net server or
> possibly GPS.  It then needs a clock referenced output of 60Hz.
> 
> 
> 
> Does such a thing exist?
> 
> 
> 
> Thank You
> 
> 
> 
> 
> 
> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> 
> http://hammondorganservice.com
> Hammond USA warranty service
> "Most people don't have a sense of humor. They think they do, but they
> don't." --Jonathan Winters
> 
> 
> 
> ___
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Re: [time-nuts] WWV or Net Clock controlled oscillator

2018-03-04 Thread Adrian Godwin

There is indeed a 60Hz out picdiv from Tom Van Baak -
http://www.leapsecond.com/pic/picdiv.htm. It's not in that list but ask Tom.

I've just used one (modified for 50Hz out) to drive a 1A H-bridge circuit
that supplies a 12V peak-peak square wave to an old LED clock, replacing
the original wall-wart.
It works very nicely, and is driven by the 10MHz output of a cheap surplus
GPSDO.


On Sun, Mar 4, 2018 at 10:21 PM, paul swed  wrote:

> Donald
> I don't know if anyone makes such a thing. But I can easily think of
> numbers of answers.
> It depends on what the Mass Rowe will allow and how comfortable you are
> with a soldering iron.
> I will guess you need to dig in and supply a better reference. I searched
> the web for mass rowe and it seems operating manuals are available but no
> schematics.
> If you can figure out how to inject a new reference things get interesting.
> It may be as simple as a tap off of the power transformer going to a
> squaring circuit.
> Easy thoughts. Oven oscillator like 6 Mhz divided down.
> Pictics a time nut makes them. Don't remember if there was a Mhz in and 60
> Hz out.
> Then you can go even more interesting with GPDSOs that are divided down to
> get the 60 Hz.
> Good luck
> Regards
> Paul
> WB8TSL
>
> On Sun, Mar 4, 2018 at 5:30 AM, D. Resor  wrote:
>
> > Hello,
> >
> >
> >
> > My first post here. I found this group's user group page while
> researching
> > a
> > source for either a WWV, GPS or Network referenced oscillator.
> >
> >
> >
> > The devices/equipment which I was able to find didn't  seem to fit the
> > requirements.
> >
> >
> >
> > What I have is a Maas-Rowe DCB1 (Digital Chronobell Series 1) clock
> > controller.
> >
> > Seen here:
> > http://hammondorganservice.com/downloads/images/carillon/
> > TempleCitySDADCB1a.
> > jpg
> >
> >
> >
> > The system can be heard playing the Westminster Chimes and striking 12
> noon
> > here:
> >
> >
> >
> > https://www.youtube.com/watch?v=Ij5c6RqGhn0
> >
> >
> >
> >
> >
> > It can be programmed to play Westminster sequences and/or music
> selections
> > using Maas-Rowe real struck chromatically tuned bell rods.
> >
> >
> >
> > This unit is installed in Southern California Edison area.  The problem
> is,
> > this unit receives its clock reference from the 60Hz AC line to keep it
> in
> > sync.  Up until a few years ago this worked very well.  Now, Edison's
> 60Hz
> > line frequency is all over the place and this clock unit now gains 30
> > seconds and/or more a week which makes it difficult to keep it
> > synchronized.
> >
> >
> >
> > The 60Hz reference can be switched out by the use of dip switches,
> however
> > that setting isn't much better.
> >
> >
> >
> > I was trying to locate a cost effective clock reference which can be
> > synchronized from either WWV, request the correct time from a net server
> or
> > possibly GPS.  It then needs a clock referenced output of 60Hz.
> >
> >
> >
> > Does such a thing exist?
> >
> >
> >
> > Thank You
> >
> >
> >
> >
> >
> > Donald R. Resor Jr. T. W. & T. C. Svc. Co.
> >
> > http://hammondorganservice.com
> > Hammond USA warranty service
> > "Most people don't have a sense of humor. They think they do, but they
> > don't." --Jonathan Winters
> >
> >
> >
> > ___
> > 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] WWV or Net Clock controlled oscillator

2018-03-04 Thread Thomas Miller

Can you supply any schematics, good images of the electronics? We may be able 
to suss out how they do the internal reference. 

I am thinking that since it has a 2.4 volt NiCd battery backup that it used 
some sort of 32,768 quartz oscillator for time keeping. It may also have some 
adjustment you can do to improve the accuracy.

There are xtal controlled 60 Hz inverters that might provide a better frequency 
reference. Even some UPS systems that run all the time could be explored.


 Good luck. 

 

 

-Original Message-
From: D. Resor 
To: Time Nuts List 
Sent: Sun, Mar 4, 2018 2:45 pm
Subject: [time-nuts] WWV or Net Clock controlled oscillator

Hello,

 

My first post here. I found this group's user group page while researching a
source for either a WWV, GPS or Network referenced oscillator.

 

The devices/equipment which I was able to find didn't  seem to fit the
requirements.

 

What I have is a Maas-Rowe DCB1 (Digital Chronobell Series 1) clock
controller.  

Seen here:
http://hammondorganservice.com/downloads/images/carillon/TempleCitySDADCB1a.
jpg

 

The system can be heard playing the Westminster Chimes and striking 12 noon
here:

 

https://www.youtube.com/watch?v=Ij5c6RqGhn0

 

 

It can be programmed to play Westminster sequences and/or music selections
using Maas-Rowe real struck chromatically tuned bell rods.

 

This unit is installed in Southern California Edison area.  The problem is,
this unit receives its clock reference from the 60Hz AC line to keep it in
sync.  Up until a few years ago this worked very well.  Now, Edison's 60Hz
line frequency is all over the place and this clock unit now gains 30
seconds and/or more a week which makes it difficult to keep it synchronized.

 

The 60Hz reference can be switched out by the use of dip switches, however
that setting isn't much better.

 

I was trying to locate a cost effective clock reference which can be
synchronized from either WWV, request the correct time from a net server or
possibly GPS.  It then needs a clock referenced output of 60Hz.

 

Does such a thing exist?

 

Thank You

 

 

Donald R. Resor Jr. T. W. & T. C. Svc. Co.

http://hammondorganservice.com
Hammond USA warranty service
"Most people don't have a sense of humor. They think they do, but they
don't." --Jonathan Winters

 

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Re: [time-nuts] Replacement A9 boards for the HP 5065A

2018-03-04 Thread Orin Eman

On Sun, Mar 4, 2018 at 1:04 PM, Charles Steinmetz 
wrote:

> So, no PTFE or PS for practical reasons.  That leaves us with PP, PPS, and
> perhaps PC.  These all have reasonably similar DA, so as long as one checks
> the particular capacitor's datasheet to verify, DA should not be much of a
> factor in choosing between them.
>

FWIW, WIMA are claiming 0.05% for their MKP 4 PP capacitors.  They
performed about the same as the original integration capacitor in my 3455A
DMM - and about the same as some Polystyrene I found online somewhere - at
the time intervals that the 3455A uses.
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Re: [time-nuts] WWV or Net Clock controlled oscillator

2018-03-04 Thread paul swed

Donald
I don't know if anyone makes such a thing. But I can easily think of
numbers of answers.
It depends on what the Mass Rowe will allow and how comfortable you are
with a soldering iron.
I will guess you need to dig in and supply a better reference. I searched
the web for mass rowe and it seems operating manuals are available but no
schematics.
If you can figure out how to inject a new reference things get interesting.
It may be as simple as a tap off of the power transformer going to a
squaring circuit.
Easy thoughts. Oven oscillator like 6 Mhz divided down.
Pictics a time nut makes them. Don't remember if there was a Mhz in and 60
Hz out.
Then you can go even more interesting with GPDSOs that are divided down to
get the 60 Hz.
Good luck
Regards
Paul
WB8TSL

On Sun, Mar 4, 2018 at 5:30 AM, D. Resor  wrote:

> Hello,
>
>
>
> My first post here. I found this group's user group page while researching
> a
> source for either a WWV, GPS or Network referenced oscillator.
>
>
>
> The devices/equipment which I was able to find didn't  seem to fit the
> requirements.
>
>
>
> What I have is a Maas-Rowe DCB1 (Digital Chronobell Series 1) clock
> controller.
>
> Seen here:
> http://hammondorganservice.com/downloads/images/carillon/
> TempleCitySDADCB1a.
> jpg
>
>
>
> The system can be heard playing the Westminster Chimes and striking 12 noon
> here:
>
>
>
> https://www.youtube.com/watch?v=Ij5c6RqGhn0
>
>
>
>
>
> It can be programmed to play Westminster sequences and/or music selections
> using Maas-Rowe real struck chromatically tuned bell rods.
>
>
>
> This unit is installed in Southern California Edison area.  The problem is,
> this unit receives its clock reference from the 60Hz AC line to keep it in
> sync.  Up until a few years ago this worked very well.  Now, Edison's 60Hz
> line frequency is all over the place and this clock unit now gains 30
> seconds and/or more a week which makes it difficult to keep it
> synchronized.
>
>
>
> The 60Hz reference can be switched out by the use of dip switches, however
> that setting isn't much better.
>
>
>
> I was trying to locate a cost effective clock reference which can be
> synchronized from either WWV, request the correct time from a net server or
> possibly GPS.  It then needs a clock referenced output of 60Hz.
>
>
>
> Does such a thing exist?
>
>
>
> Thank You
>
>
>
>
>
> Donald R. Resor Jr. T. W. & T. C. Svc. Co.
>
> http://hammondorganservice.com
> Hammond USA warranty service
> "Most people don't have a sense of humor. They think they do, but they
> don't." --Jonathan Winters
>
>
>
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> mailman/listinfo/time-nuts
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>
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Re: [time-nuts] Replacement A9 boards for the HP 5065A

2018-03-04 Thread Charles Steinmetz


Poul-Henning wrote:


I fully agree, and if it were me, I would absolutely use the best
capacitor I could find at a non-insane price.

But that was exacly my point:  The only thing you (might!) get by
spending an *insane* amount of money on that capacitor is PTFE and
its better dielectric absorption. * * *
And third, the difference in DA between PTFE and Polystyrene is
barely a factor five and it is from 0.05%(PS) to 0.01%(PTFE).


I agree, no PTFE (as I said in a previous message) because it is simply 
impractible (or even impossible) to fit on a board that fits into the 
5065A.  But as I said in the same message, that is also true of PS 
(also, I'm not aware of any currently available in integer uF values).


Last I knew, there are (were?) at least 3 reputable suppliers of PTFE 
capacitors, but none of my designs in current production uses them so I 
don't have any recent experience.  I do see that Electrocube still lists 
the 463D series on a web page with a 2018 copyright date.


I concur with everything you say about alleged PTFE caps from 
"alternative" suppliers.


So, no PTFE or PS for practical reasons.  That leaves us with PP, PPS, 
and perhaps PC.  These all have reasonably similar DA, so as long as one 
checks the particular capacitor's datasheet to verify, DA should not be 
much of a factor in choosing between them.


Best regards,

Charles


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Re: [time-nuts] Replacement A9 boards for the HP 5065A

2018-03-04 Thread Poul-Henning Kamp

In message <5a9c4644.5030...@yandex.com>, Charles Steinmetz writes:

>Some times, "just because it's better" is a sufficient
>reason to overdesign, particularly where the incremental cost is low and
>especially where the projected number of units is low, both of which are
>true WRT the improved A9 board.

I fully agree, and if it were me, I would absolutely use the best
capacitor I could find at a non-insane price.

But that was exacly my point: The only thing you (might!) get by
spending an *insane* amount of money on that capacitor is PTFE and
its better dielectric absorption.

But there are three good reasons not to.

First, they are HUGE, typically a couple of inches in diameter and
four or five inches long[1]

Second, there are no reputable suppliers of ~5µF PTFE capacitors
that I have been able to find, there are only audiohomoeopaths.

*Nowhere* have I seen anybody buy an audiohomoepathy PTFE capacitor
and publish a traceable DA measurement for it, much less information
about tolerance, lot variations etc.

I am certainly not going to shell out $785.07 for what is claimed
to be a newly produced PTFE capacitor[2]:

https://www.v-cap.com/cutf-capacitors.php

Neither am I going to shell out $34.70 for something which may or
may not be USSR army surplus and which may or may not be PTFE[3].

https://www.ebay.co.uk/itm/Lot-of-1-piece-K72-11-Teflon-Capacitors-0-22uF-4-7uF-125V-1000V-NOS-Tested/132443841947?hash=item1ed644a59b:m:mPF1aOO4F7dJXTSF0qHKcSQ

And third, the difference in DA between PTFE and Polystyrene is
barely a factor five and it is from 0.05%(PS) to 0.01%(PTFE).

That is simply not going to make *any* difference in an HP5065A.

The trick here is to do the math on the S/N ratio of the optical
signal: The A9-capacitor is primarily a low-pass filter, and pretty
much any sane capacitor can do that.

Poul-Henning

[1] Almost any other type of capacitor is wound from two layers of
insulator on which a thin layer of metal has been deposited by
evaporation or sputtering. PTFE must be wound from two PTFE films
and two metal films, which means a lot more metal, because it must
have the mechanical strength for the winding operation.

[2] Notice the claimed "dielectric coefficient of 1.45" ? Either
he means "Dielectric Absorption" in which case the number is in %
and *horrible*, or he means "Dielectric Constant" in which case the
number is physically impossible.

[3] Because USSR wasn't very good at PTFE to begin with.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] Z3801A OCXO manual trimming

Hi

> On Mar 4, 2018, at 1:13 PM, Joe Hobart  wrote:
> 
> My Z3801A failed about a year ago (there was a warning the electronic 
> frequency
> control was nearing a limit).
> 
> Symptoms (most from GPS Control and Lady Heather:
> 
>   Frequency about 1E-8 low
> 
>   Time Invalid  (many hours off)
>   Date 6 months old
>   DAC 99.9969 percent
>   Life 72K Hours
> 
> Lady Heather shows the following as OK:
> 
>   ROM, RAM, OSC GPS, Power, EEPROM, Antenna, Discipline, 5 satellites
> 
> GPS Con shows the following:
> 
>   EFC: ERR
>   No time display
>   Outputs Invalid
> 
> Only the front panel power light is lit.
> 
> This suggests either the crystal has aged or the heater temperature has 
> drifted
> slightly.  I hear/read that opening the oscillator is difficult.  Is there a
> usable adjustment?
> 
> What have others done to restore operation?  Is it time to consider a 
> different
> time & frequency standard?

With enough effort and enough time spent troubleshooting, you probably can 
fix the beast. You might have to swap out the OCXO, but that’s still just a 
repair
process. The bigger question is indeed how much work to put in. 

The basic approach is to fire up a counter and get into the EFC voltage line.
Swing it to both limits and see what the frequency does. That will give you 
an idea if it’s the OCXO or if it’s the DAC side of things. 

The 3801 was made for a while. Some are hitting 20 years old at this point. 
Mine seem to eat power supply components from time to time. One of these
days, whatever it is that pops the fuse will do more damage. 

Back when the 3801 hit the surplus market there really was not a whole lot
else to look at. These days, we’re hip deep in a whole range of units sourced
mostly from “China Electronic Salvage Inc”.  Who knows …. maybe one day
there will be another TimeNuts TBolt “sale”…..

Bob

> 
> Thanks,
> Joe, W7LUX
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[time-nuts] WWV or Net Clock controlled oscillator

2018-03-04 Thread D. Resor

Hello,

 

My first post here. I found this group's user group page while researching a
source for either a WWV, GPS or Network referenced oscillator.

 

The devices/equipment which I was able to find didn't  seem to fit the
requirements.

 

What I have is a Maas-Rowe DCB1 (Digital Chronobell Series 1) clock
controller.  

Seen here:
http://hammondorganservice.com/downloads/images/carillon/TempleCitySDADCB1a.
jpg

 

The system can be heard playing the Westminster Chimes and striking 12 noon
here:

 

https://www.youtube.com/watch?v=Ij5c6RqGhn0

 

 

It can be programmed to play Westminster sequences and/or music selections
using Maas-Rowe real struck chromatically tuned bell rods.

 

This unit is installed in Southern California Edison area.  The problem is,
this unit receives its clock reference from the 60Hz AC line to keep it in
sync.  Up until a few years ago this worked very well.  Now, Edison's 60Hz
line frequency is all over the place and this clock unit now gains 30
seconds and/or more a week which makes it difficult to keep it synchronized.

 

The 60Hz reference can be switched out by the use of dip switches, however
that setting isn't much better.

 

I was trying to locate a cost effective clock reference which can be
synchronized from either WWV, request the correct time from a net server or
possibly GPS.  It then needs a clock referenced output of 60Hz.

 

Does such a thing exist?

 

Thank You

 

 

Donald R. Resor Jr. T. W. & T. C. Svc. Co.

http://hammondorganservice.com
Hammond USA warranty service
"Most people don't have a sense of humor. They think they do, but they
don't." --Jonathan Winters

 

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Re: [time-nuts] While we are talking about Z3801's

2018-03-04 Thread John Green

Hal, I can't communicate with it. That has been gone for a while now.

On Sat, Mar 3, 2018 at 9:05 PM, Hal Murray  wrote:

> > Mine has quit achieving lock.
> ...
> > After reading about someone else's trouble, i wonder if my OCXO has aged
> > out.
>
> Have you checked the status page?  Is the GPS unit seeing satellites?
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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Re: [time-nuts] Z3801A OCXO manual trimming

2018-03-04 Thread Joe Hobart

My Z3801A failed about a year ago (there was a warning the electronic frequency
control was nearing a limit).

Symptoms (most from GPS Control and Lady Heather:

   Frequency about 1E-8 low

   Time Invalid  (many hours off)
   Date 6 months old
   DAC 99.9969 percent
   Life 72K Hours

Lady Heather shows the following as OK:

   ROM, RAM, OSC GPS, Power, EEPROM, Antenna, Discipline, 5 satellites

GPS Con shows the following:

   EFC: ERR
   No time display
   Outputs Invalid

Only the front panel power light is lit.

This suggests either the crystal has aged or the heater temperature has drifted
slightly.  I hear/read that opening the oscillator is difficult.  Is there a
usable adjustment?

What have others done to restore operation?  Is it time to consider a different
time & frequency standard?

Thanks,
Joe, W7LUX
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Re: [time-nuts] Replacement A9 boards for the HP 5065A

2018-03-04 Thread Charles Steinmetz


Poul-Henning wrote:


The input signal to the integrator is continuous and jump-free and
the relevant time constant is sub-second.  Dielectric absorption
doesn't matter when there are no voltage jumps.


That is a very common misconception, probably fostered by the usual test 
methodology for DA.  But it is not correct.


DA is a charge-migration phenomenon, so it occurs *whenever the charge 
on a capacitor changes.*  A step function in the charge very obviously 
represents such a change (and for this reason is used for testing the 
parameter in most circumstances), but so do gradual changes in the 
driving charge.  These can be less obvious (than step changes), 
depending on the time scale of the change relative to the time scale of 
the DA process in the particular capacitor.


There are several dimensions to DA -- not just how much charge isn't 
returned immediately, but what the "tail" looks like (i.e., the time 
profile of charge return, generally measured as current vs. time). 
Different dielectrics (and, to a certain extent, different construction 
techniques) exhibit different charge-return profiles.


Long-TC integrators do tend to mask the effects of DA, because the time 
scale of changes in the driving charge is closer to the time scale of 
the delayed charge return caused by DA.  But that does not mean that DA 
isn't important, because slow integrators are frequently used where 
extremely high precision is required (such as integrators for 
high-resolution DACs and EFC servos for precision oscillators), so the 
tolerable amount of delayed charge return is extremely low.


As with any circuit, the A9 integrator is "good enough" when the errors 
it causes are swamped by other accumulated errors.  But I'm no fan of 
"just good enough" design, particularly in a case like the 6065A where 
time nuts are diligently working to improve the performance of the 
instrument.  Some times, "just because it's better" is a sufficient 
reason to overdesign, particularly where the incremental cost is low and 
especially where the projected number of units is low, both of which are 
true WRT the improved A9 board.


Best regards,

Charles


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Re: [time-nuts] Z3801A OCXO manual trimming

Hi

Heater failure is pretty easy to spot. You will be *way* off frequency. No need 
for a 
GPSDO in your counter to see if it’s out by 0.0001 Hz. You should be > 20 Hz low
in frequency. Since there *are* multiple heaters, there are some odd 
combinations
in a 3801. Your inner heater can be dead, but the outer heater still works. The 
unit
will look like it’s warming up but doing so *really* slowly. 

Based on seeing a lot of 10811’s and a lot of modern OCXO’s, a crystal that 
ages out
is pretty rare. The “something else” category is way more likely when diving 
into one
that is off frequency. That wasn’t always true so you can go back far enough in 
time 
(like into the 60’s) and find units that have aged out. They also aged out in 
the first 
ten years after they left the factory. Things got a lot better over the years 
in terms of
long term precision crystal aging ….

Bob

> On Mar 3, 2018, at 10:12 PM, Tom Holmes  wrote:
> 
> Bob...
> 
> Interesting point about the heater not working vs the XTAL having drifted too 
> far. Mine has the same symptoms as the others reported (EFC at the end of its 
> rope) but have not tackled it yet, figuring I'd have to dismantle the whole 
> thing. Certainly troubleshooting a non-operating heater would be much more 
> pleasant.
> 
> Thanks for that insight.
> 
> Tom Holmes, N8ZM
> 
> -Original Message-
> From: time-nuts  On Behalf Of Bob kb8tq
> Sent: Saturday, March 03, 2018 2:07 PM
> To: Tom Curlee ; Discussion of precise time and 
> frequency measurement 
> Subject: Re: [time-nuts] Z3801A OCXO manual trimming
> 
> Hi
> 
> First off some basics about OCXO’s.
> 
> In a single oven design, you have a heater that warms up the entire crystal 
> and the guts of the oscillator. It is on all the time and 
> it gets things up to a temperature that makes sense for a given crystal. It 
> can be adjusted based on manufacturing data or by 
> trial and error to match the characteristics of that crystal. 
> 
> In a double oven design, you have two ovens that are on all the time. One 
> heats up the other one. They both work together to
> achieve the end result. The gain of one adds to the gain of the other to give 
> an improved result. On some double ovens, the 
> entire heat range of the inner oven is only 10’s of degrees ….
> 
> In a boosted oven, you have a second heater to get things going when it is 
> very cold. This is an unusual approach and rarely 
> seen. Its normally easier to just design a bit more power into the main oven 
> circuit. In a boosted design, the boost heat goes
> away in normal operation at typical temperatures. In normal operation, the 
> gain of the boost circuit does not count. 
> 
> SO ….
> 
> The oscillator in the Z3801 is a boosted 10811. It is boosted to allow them 
> to hit a spec of -40C on the unit. At the time it was
> designed, there was talk about mounting these things in un-heated boxes 
> outdoors. After they got a bit further into all the 
> details of the designs … that part went away. The spec still hung around long 
> enough to apply to very early designs. 
> 
> The net result is that you can pretty much destroy the outer heater stuff and 
> the oscillator will work fine. There is no need 
> for it in a typical lab. There are some alarm triggers that need to be wired 
> “ok” when you do so. The details are in the archives. 
> 
> But …
> 
> Best guess if your unit is at max EFC = the “real” heater on the 10811 has 
> quit working. To get at that, you will need to dig 
> into the guts of the unit. Given the massive EFC on the Z3801 version of the 
> oscillator, it would take a crazy amount of aging
> to hit limit.
> 
> Bob
> 
> 
>> On Mar 3, 2018, at 1:37 PM, Tom Curlee  wrote:
>> 
>> Since the Z3801A is being discussed, I thought I'd ask about an issue I'm 
>> having with my unit.  I use my Z3801 as my working lab standard for the 
>> usual pieces of RF test equipment.  In the past year or so I've had the unit 
>> drop out of lock and go into standby mode.  Resetting/cycling power would 
>> bring it back into lock for a while, but it generally got worse and now 
>> stays in hold over mode.  LH (thanks Mark Sims!!) reports that everything is 
>> operating normally except that the it has a PLL unlock.  The one highly 
>> suspicious item is that the DAC is at 99.996902% - full output.
>> The unit shows it has over 94.5K hours run time, so I suspect that the OCXO 
>> has aged to the point that the EFC can't pull it into lock.  I disassembled 
>> the OCXO to see if it had a trimmer capacitor like the standard 10811 units. 
>>  After removing the outer case and foam insulation, I see that the outer 
>> heater is one of the thin printed circuit serpentine heaters on what I think 
>> is Kapton.  That would need to be peeled off of the case to either get to 
>> the hole for the trimmer (if there is one) or to remove the cover

Re: [time-nuts] 50 ohm drivers

Hi

We have gone over CMOS 50 ohm line driving a bunch of times. Check the archives 
for all
of the various opinions. A quick summary:

If you are driving CMOS, the output swing does not have to hit 99% of the 
supply. You
can do a pretty good job with gates in parallel and no source termination. 

If you want both source and load termination *and* want 5V p-p on the load, you 
will
need a 10V p-p source. Good luck if that source ever gets tied to a “normal” 
CMOS 
input. Something made from 2N3904’s and 2N3906’s is probably your best bet 
(along 
with dual supplies) if *really* want to do this.

Source termination (open load) is the low power approach. Cable reflections are 
minimized
and you don’t use a lot of power.

===

If all you are after is sine wave signals, a pair of gates running on 5V will 
give you 20 dbm 
without a lot of effort. There aren’t many applications in the timing world 
that need more
power than that. 

Bob

> On Mar 3, 2018, at 9:17 PM, David C. Partridge 
>  wrote:
> 
> Brice said:
> 
>> . Some fast CMOS devices (esp clock drivers) have an output R close to 50
> ohms as they are intended to drive 50 ohm source terminated transmission
> lines.
> 
> Any in particular that you'd recommend?   I need to drive a 50ohm line and a
> single gate inverter doesn't have the grunt to do so ...
> 
> Thanks
> David
> 
> 
> 
> 
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Re: [time-nuts] X72 and 1pps

2018-03-04 Thread Matthias Jelen

Hi Mark,

thanks for your reply.

Try enabling the PPS input form the "P menu.
I can´t find this option - I can toggle the PPS output, but
not the input.

BTW, what´s the "set TIC" option? I can enter a number here,
but I can´t find something about this command in the manual...

Auto-Tune seems to work well - I see the plot stepping
and a slope is calculated.

What´s the expected behaviour if I go to d-e: "Enable HW
discipline" ? I can´t see any changes here.

I checked the SA.22.C manual as well, but this contains more
or less the same information as the X72.

Regards,

Matthias

Also, to verify that it is using the PPS input try the auto-tune command.
It will set the TIC and DDS tune word to to 0, collect data for for however long
you requested (an hour is a good start), then calculate the drift rate and set the
DDS tune word to put the device on frequency. The EE command should set save the
DDS word in EEPROM.If the unit is seeing the PPS input, you should see the PPS
plot stepping as the DDS freq drifts.

Many of the X72 settings cannot be read back from the unit. Heather maintains a "software eeprom"
with the settings that it knows about in the file "tbeeprom.dat". Until you update a setting, what
is displayed for that setting may not be correct. Use the "P" menu to set each of the settings so
that Heather can learn what they are. When Heather starts up, it restores all the last settings from the
file.
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[time-nuts] lasers (was: Microsemi up for sale?)

2018-03-04 Thread Attila Kinali

On Sat, 3 Mar 2018 19:04:57 -0800
"Richard (Rick) Karlquist"  wrote:

> On 3/3/2018 6:18 PM, Hal Murray wrote:
> > Thanks.
> > 
> > Is there something fundamental in there, or is the lack of products because
> > nobody has made the big investment required to figure out how to do it.
> > 
> > What is the bandwidth of the laser?  What happens if it drifts slightly?  
> > Can

Commercial laser diodes are available with line widths from 10MHz up
to a few 100MHz. The problem with this is, that the center frequency
varies with temperature and current. As ballpark figures you can
use 10GHz per °C and mA.

For laser pumping of atomic states, you need to stabilize the laser diode
with additional feedback, a so called extended cavity diode laser (ECDL).
Most commonly these days, a grating[1] or a distributed feedback (DFB, 
DFB external to the diode laser cavity is called "volume grating")
is used. The grating can be thought of as a mirror with wavelength/frequency
dependent reflection angle. A DFB is basically a wavelength selective
filter. Both, grating and DFB are put in the laser path, such that
they become part of the cavity, ie add another frequency selective element
to the laser "oscillator". With this, one can get the linewidht down
to 1kHz to 1MHz, mostly dependent on the strength of the feedback and
on how much temperature and current fluctuations affect the center
frequency.

A good summary on how different factors add up in an ECDL can be found
in [3]. The authors also presented a neat and cheap way how to build
an ECDL in [4]. An alternative, a bit more complicated, but also more
complete description can be found in [5].

Under the assumption you have selected the right diode and designed
the feedback system well, you can get system that will be first order
indepented of the laser diodes behaviour. I.e. the external cavity
will be the main wavelength determining element. 

The problems for long term use in commercial standards seem to be
the second order effects. Mainly the position of mode jumps (sudden,
large jumps of frequency when applying only a small change of tuning
to the system). While it is easy to tune the ECDL such, that these
mode jumps do not happen withing the region of interest, it is not
so easy to ensure that aging does not bring one of these mode jumps
right to the point where one would like to keep the laser. Detecting
of these mode jumps is also not easy, the straight forward way requires
a second laser to measure the difference frequency. A second way of
using the amplitude varation during mode jumps seems not to be as reliable.

But! For 1.5µm communication laser systems, all these problems have
been solved and we have very reliable lasers that stay on frequency
with a very high stability (modern laser communication systems use
a channel spacing as low as 1GHz @ 1.5µm). So there is hope that
these techniques will spill over to wavelength ranges more interesting
to atomic standards. Most likekly the first one would be 850nm
(close to the Ceasium D2 line), which is being used for short range,
cheap optical networks.

> When I was working on fiber optic communication test,
> I remember hearing about lasers that were "tuned" with
> variable Peltier coolers.  Power consumption is critical in
> a cesium standard that can run on batteries.  Maybe
> the power consumption of the coolers is a deal breaker.

If all you have is just a laser diode with at most DFB, but no
external cavity (as is usualy with communication lasers), then
the only two ways to tune are temperature and current.
But current will also modulate intensitiy, so people tend
to try to keep current more or less constant, while doing
the tuning with temperature. For a system with external
cavity, it's enough to keep current and temperature stable,
which makes the power consumption less pronounced. The gotcha
here is, that one might need to tune temperature a bit to
move a mode jump out of the way.

But even if you dont have an ECDL, it's only a laser you
have to cool, which is a very low mass, and the cooling power needed
is just what you pump into it (usually a 5mW laser is enough
for atomic spectroscopy, which translates to <100mW electrical
power needed).

On Sun, 4 Mar 2018 21:41:15 +1300 (NZDT)
Bruce Griffiths  wrote:

> External cavity lasers with piezoelectric tuning (usually varies cavity 
> length or tilts frequency selective grating) are usually used for such 
> applications.
> 
> Sacher laser do some compact units with integrated Peltier cooler etc:
> 
> https://www.sacher-laser.com/home/industrial-lasers/point_and_line_laser_module/industrial_laser_modules/micron_laser.html
> 
> To get pricing registration is required.

The Sacher module is a neat little device, that integrates all of the
components needed into a tiny little package. More information on its
construction and performance can be found in [6] (note: their calculation
of linewidth is wrong, it

Re: [time-nuts] Microsemi up for sale?

2018-03-04 Thread Anders Wallin

>
> rich...@karlquist.com said:
> > 2.  Magnetic state selection, as used in the 5071A, would be replaced by
> > optical pumping.  Len Cutler was heartbroken that HP/Agilent management
> > wouldn't fund this effort.
>
> > It turns out that, even now in 2018, optical pumping is not ready for
> prime
> > time in a working standard because the lasers drift over time.
>
> Is there something fundamental in there, or is the lack of products because
> nobody has made the big investment required to figure out how to do it.
>

FWIW, OSA has been giving at leat one talk per year on their optical Cs
work, and as others have noted it's been coming "real soon" for a couple of
years now.
Here are some links:
2015 November:
http://www.chronos.co.uk/files/pdfs/itsf/2015/day2/1410_High_performance_optically-pumped_cesium_beam_clock-PBerthoud-Oscilloquartz.pdf

2017 April:
https://www.atis.org/wsts/library/2017/5-03_Oscilloquartz_Berthoud_Michaud_Optical%20Cs%20Beam%20clock%20for%20ePRTC%20applications_revision20170327.pdf
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Re: [time-nuts] LT1016 as a pulse shaper...

That just confirms that they are clueless when it comes to accurately measuring 
additive PN.

To get the real additive PN one would have to measure it for oneself.

If I had a suitable PCB board for it I would do the measurement properly.


Bruce

> 
> On 04 March 2018 at 23:59 Leo Bodnar  wrote:
> 
> Not sure how calculated this - the PN chart for PL133-37 shows output 
> jitter barely lifting off the input jitter trace. LT do not say what their 
> input jitter is.
> 
> Additive jitter for 100MHz 12kHz-20MHz is 80fs for PLL133-37 and 90fs for 
> LTC6957 at more than 10 times lower price.
> 
> I would trust LT more but all this is still armchair engineering. The 
> only way to know is stick it on the board and check.
> 
> Note that PLL133-37 is AC coupled internally so not suitable for short 
> sharp spikes or low frequencies.
> 
> Cheers
> Leo
> 
> On 4 Mar 2018, at 10:20, Bruce Griffiths wrote:
> 
> > > 
> > Somewhat worse than an LTC6957 particularly at low offset 
> > frequencies.
> > 
> > Either that or the manufacturers PN noise measurement method 
> > doesn't work well at low offsets.
> > 
> > Bruce
> > 
> > On 04 March 2018 at 22:34 Leo Bodnar  wrote:
> > 
> > Ulf,
> > 
> > What level of jitter would you consider acceptable?
> > 
> > Try PL133-37, I am using it for sinewave shaping on some of designs 
> > - including my 30ps pulser.
> > 
> > Leo
> > 
> > > 
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Re: [time-nuts] LT1016 as a pulse shaper...

2018-03-04 Thread Leo Bodnar

Not sure how calculated this - the PN chart for PL133-37 shows output jitter 
barely lifting off the input jitter trace.  LT do not say what their input 
jitter is.

Additive jitter for 100MHz 12kHz-20MHz is 80fs for PLL133-37 and 90fs for 
LTC6957 at more than 10 times lower price.

I would trust LT more but all this is still armchair engineering.  The only way 
to know is stick it on the board and check.

Note that PLL133-37 is AC coupled internally so not suitable for short sharp 
spikes or low frequencies. 

Cheers
Leo

On 4 Mar 2018, at 10:20, Bruce Griffiths wrote:
> Somewhat worse than an LTC6957 particularly at low offset frequencies.
> 
> Either that or the manufacturers PN noise measurement method doesn't work 
> well at low offsets.
> 
> Bruce
> 
> On 04 March 2018 at 22:34 Leo Bodnar  wrote:
> 
> Ulf,
> 
> What level of jitter would you consider acceptable?
> 
> Try PL133-37, I am using it for sinewave shaping on some of designs - 
> including my 30ps pulser.
> 
> Leo
> 

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Re: [time-nuts] LT1016 as a pulse shaper...

Somewhat worse than an LTC6957 particularly at low offset frequencies.

Either that or the manufacturers PN noise measurement method doesn't work well 
at low offsets.

Bruce

> 
> On 04 March 2018 at 22:34 Leo Bodnar  wrote:
> 
> Ulf,
> 
> What level of jitter would you consider acceptable?
> 
> Try PL133-37, I am using it for sinewave shaping on some of designs - 
> including my 30ps pulser.
> 
> Leo
> 
> On 3 Mar 2018, at 21:56, time-nuts-requ...@febo.com wrote:
> 
> > > 
> > From: Ulf Kylenfall 
> > 
> > Gentlemen,
> > I have so far been using LT1016 as a pulse shaper and also whenever 
> > I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and 
> > all the decouplingand layout precautions as recommended by LT.
> > Are there any similar or better alternatives out there that could 
> > be usedthat would provide lower jitter and that are less expenceive?
> > Ulf Kylenfall
> > SM6GXV
> > 
> > > 
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Re: [time-nuts] LT1016 as a pulse shaper...

2018-03-04 Thread Leo Bodnar

Ulf, 

What level of jitter would you consider acceptable?

Try PL133-37, I am using it for sinewave shaping on some of designs - including 
my 30ps pulser.

Leo

On 3 Mar 2018, at 21:56, time-nuts-requ...@febo.com wrote:

> From: Ulf Kylenfall 
> 
> Gentlemen,
> I have so far been using LT1016 as a pulse shaper and also whenever I needed 
> toconvert a sine wave into TTL Logic levels. Some hysteresis and all the 
> decouplingand layout precautions as recommended by LT.
> Are there any similar or better alternatives out there that could be usedthat 
> would provide lower jitter and that are less expenceive?
> Ulf Kylenfall
> SM6GXV

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[time-nuts] IEEE 1588 PTP devices

2018-03-04 Thread Jeff Woolsey

I ran across some Agilent LXI 1588 Demomstration [sic] Kits for far, far
less (beer money) than what
https://www.ebay.com/itm/Agilent-IEEE-1588-Demonstration-Kit-New-in-box/161954792190
wants. There are 4 BNCs on the back, labelled 1PPS, TT, TS, and TEST. 
With that, and Ethernet and serial and USB on the back, they looked
intersting enough to take one home and play with.  That's all I knew
about them.  I thought I might be able to inject PTP time with 1PPS from
my GPSDO into my NTP network.

I found that it had a webserver for configuring from a browser, and
that's the only way I've found (so far) to set the time.  So it's an
island of precision unto itself and any brethren it finds.  I tried to
get linuxptp to talk to it, but it could only listen (I guess the LXI
box thinks that itself is the best master clock).  I wondered how well
it would sync to another PTP box. So I went and picked up another one.

It seems they sync to each other pretty well.  I was hoping that the
1PPS BNC was an input.  Alas, it's an output.  (The GUI also told me
that the TEST input is an external 100MHz clock.) I put each one's PPS
on a scope and measure the difference as about -11ns to +40ns
(jittering). Tried the same thing on a 53131A (also Agilent).  It was so
noisy I couldn't trust/believe what it reported, though a single 22.8ns
did come up.  I couldn't do that on the 5316A, since its resolution is
100ns, so I had it report GPSDO 1PPS vs LXI GPS.

LinuxPTP can at least tell me the difference between NTP (host) time and
PTP time (but not when it is a master), and it takes a couple days to
roll over one second.  I'd been arguing with these things a while trying
to get it to timestamp an external event.  Only one seems to be able to
do that so far.  So I gave it the GPSDO 1PPS to TimeStamp, and data
started accumulating.   From the TS log, I can see that its clock is a
bit less than 3ppm slow (slower if it gets colder in the lab, er,
garage).  It reports everything to nanosecond precision.

typical timestamp: 1519980450.210347925   linuxptp reports difference
between PTP and host in nanoseconds, typical value 786979741 .  That
sums close to the next second.  The difference is positive and rising now.

==

Does anyone out there have any info on these things?  I did look through
time-nuts archives around 2012.

-- 
Jeff Woolsey {{woolsey,jlw}@jlw,first.last@{gmail,jlw}}.com
Nature abhors straight antennas, clean lenses, and empty storage.
"Delete! Delete! OK!" -Dr. Bronner on disk space management
Card-sorting, Joel.  -Crow on solitaire

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Re: [time-nuts] Microsemi up for sale?