Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[Bob Camp]

Hi

At least in my “unconstrained by reality” state, my thought is that the “sync” 
PPS signal is there all the time. 
You are as much doing a phase lock as a sync. The “PLL” only has a phase 
resolution of 100 ns so once
it’s running, not much happens. Yes, this might get you into all sorts of 
issues like some D-FF’s for early / late
detection. Things are getting more complex ……

Bob


> On Nov 27, 2016, at 7:18 PM, John Ackermann N8UR  wrote:
> 
> Hi Bob --
> 
> It's certainly possible to synchronize the TICC timescale epoch to an 
> external pulse at startup.  The external sync pulse would have to 
> simultaneously reset (a) the picDIV and (b) the coarse (100us) counter in the 
> Arduino. The signals to do that are available, so it's a worthwhile 
> experiment.
> 
> I have to think through whether there are any other gotchas but I'm pretty 
> sure that you would not get closer than a few hundred nanoseconds given how 
> closely the picDIV can sync -- I think Tom specifies that it's within 4 
> clocks, or 400 ns.
> 
> (Now, syncing two TICCs to each other is a different matter because there we 
> one unit is master and provides the coarse clock directly to the slave; if 
> both units are run from the same 10 MHz clock they should align within one 10 
> MHz tick.)
> 
> John
> 
> 
> On 11/27/2016 12:26 PM, Bob Camp wrote:
>> Hi
>> 
>> Ok, so the guess was fairly close :)
>> 
>> How about a connector to allow an external PPS to reset the internal 10 MHz 
>> divider? That way all
>> the data is “in sync� with the house standard. If I want to know that my 
>> GPSDO is +32.751 ns off from
>> the house standard, I just look at the data on a terminal program …
>> 
>> Or am I missing something really obvious (again)?
>> 
>> Bob
>> 
>>> On Nov 27, 2016, at 10:04 AM, John Ackermann N8UR  wrote:
>>> 
>>> Good guess.  The 10 MHz reference drives all the logic on the board, and 
>>> particularly the counter that maintains a local timescale in 100us 
>>> increments; the TDC7200 interpolates between the 100us ticks to stamp 
>>> incoming events on channel A and/or B with picosecond precision.  The 
>>> stamps on both channels are referenced to the same local timescale.
>>> 
>>> Therefore, you can do a measurement of a PPS source against the 10 MHz 
>>> reference and the resulting timestamp output can be processed by TimeLab or 
>>> whatever into stability data (the requirement being that the software knows 
>>> how to deal with timestamps that increment by the nominal measurement rate, 
>>> e.g., 1 second per measurement for PPS data).
>>> 
>>> So with PPS from GPSDO "A" on channel A the timestamp output after 
>>> unwrapping will show the phase of A vs. 10 MHz.
>>> 
>>> You can add PPS from GPSDO "B" on channel B and the TICC will also output 
>>> timestamps of B vs. the 10 MHz source.
>>> 
>>> If you want, you can subtract A from B to get the time interval between the 
>>> two GPSDO, since both timestamp measurements are against a common 
>>> timescale.  The TICC has a mode to output the (B-A) difference, so it can 
>>> act as either a traditional time interval counter, or as a two-channel 
>>> timestamping counter.
>>> 
>>> And as noted in my other message to Luciano, the TICC can also output both 
>>> timestamp and time interval data simultaneously to allow three-corner-hat 
>>> measurements of (A-C, B-C, B-A) where C is the 10 MHz reference.
>>> 
>>> John
>>> 
>>> 
>>> On 11/27/2016 09:24 AM, Bob Camp wrote:
 Hi
 
 Without doing a bunch of actual *work* I’m not sure what is inside 
 the guts of the board. Being
 lazy I’ll just guess ….
 
 There appears to be a 10 MHz time base input and a pair of measurement 
 inputs. In a lot us will
 be comparing to a “house standard�. That standard has a pps 
 output that is related directly to
 the 10 MHz reference. If I can uniquely identify one edge (out of 10 
 million edges) as the right
 edge, I can use the 10 MHz as my pps reference. Put another way, I 
 don’t really need to measure
 a pps input from the house standard if I’m already locked up in 
 phase to the 10 MHz. All I need to
 do is to tag an edge / reset a counter.
 
 The advantage of this is that I may not need another fancy TDC chip to set 
 up the reference. I can
 use *both* inputs for DUT’s rather than using one as a reference.
 
 Part of the reason I’m guessing this would work is the claim that 
 boards can be stacked for multiple
 input setups ….
 
 Bob
 
> On Nov 27, 2016, at 7:36 AM, timeok  wrote:
> 
> 
>   Hi John,
> I have planned to buy two TICC.
> An interesting feature would be to be able to do two simultaneous 
> acquisitions,
> and Timelab as real time display,using the two indipendent input channels 
> and the 10Mhz clock 

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[Tom Van Baak]

John,

The PD15 divider that you're using will sync to within 1 PIC instruction. 
That's sounds good, but the TICC reads down to picoseconds so the 400 ns PIC 
granularity will look pretty high.

There is another solution. And that is not to sync the h/w or s/w counters at 
all. You just let them free-run. But you allow a sync mode where the user 
places a known UTC 1PPS in chA or chB and then the Arduino takes a reading. 
That number is then stored and subtracted from all subsequent readings that the 
Arduino outputs. It's better than a h/w sync because it allows you to sync to 
the ps level. And it also takes into account any propagation delays on your 
board, connector and cables.

/tvb

- Original Message - 
From: "John Ackermann N8UR" 
To: 
Sent: Sunday, November 27, 2016 4:18 PM
Subject: Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC


Hi Bob --

It's certainly possible to synchronize the TICC timescale epoch to an 
external pulse at startup.  The external sync pulse would have to 
simultaneously reset (a) the picDIV and (b) the coarse (100us) counter 
in the Arduino. The signals to do that are available, so it's a 
worthwhile experiment.

I have to think through whether there are any other gotchas but I'm 
pretty sure that you would not get closer than a few hundred nanoseconds 
given how closely the picDIV can sync -- I think Tom specifies that it's 
within 4 clocks, or 400 ns.

(Now, syncing two TICCs to each other is a different matter because 
there we one unit is master and provides the coarse clock directly to 
the slave; if both units are run from the same 10 MHz clock they should 
align within one 10 MHz tick.)

John


On 11/27/2016 12:26 PM, Bob Camp wrote:
> Hi
>
> Ok, so the guess was fairly close :)
>
> How about a connector to allow an external PPS to reset the internal 10 MHz 
> divider? That way all
> the data is “in sync� with the house standard. If I want to know that my 
> GPSDO is +32.751 ns off from
> the house standard, I just look at the data on a terminal program …
>
> Or am I missing something really obvious (again)?
>
> Bob
>
>> On Nov 27, 2016, at 10:04 AM, John Ackermann N8UR  wrote:
>>
>> Good guess.  The 10 MHz reference drives all the logic on the board, and 
>> particularly the counter that maintains a local timescale in 100us 
>> increments; the TDC7200 interpolates between the 100us ticks to stamp 
>> incoming events on channel A and/or B with picosecond precision.  The stamps 
>> on both channels are referenced to the same local timescale.
>>
>> Therefore, you can do a measurement of a PPS source against the 10 MHz 
>> reference and the resulting timestamp output can be processed by TimeLab or 
>> whatever into stability data (the requirement being that the software knows 
>> how to deal with timestamps that increment by the nominal measurement rate, 
>> e.g., 1 second per measurement for PPS data).
>>
>> So with PPS from GPSDO "A" on channel A the timestamp output after 
>> unwrapping will show the phase of A vs. 10 MHz.
>>
>> You can add PPS from GPSDO "B" on channel B and the TICC will also output 
>> timestamps of B vs. the 10 MHz source.
>>
>> If you want, you can subtract A from B to get the time interval between the 
>> two GPSDO, since both timestamp measurements are against a common timescale. 
>>  The TICC has a mode to output the (B-A) difference, so it can act as either 
>> a traditional time interval counter, or as a two-channel timestamping 
>> counter.
>>
>> And as noted in my other message to Luciano, the TICC can also output both 
>> timestamp and time interval data simultaneously to allow three-corner-hat 
>> measurements of (A-C, B-C, B-A) where C is the 10 MHz reference.
>>
>> John
>> 
>>
>> On 11/27/2016 09:24 AM, Bob Camp wrote:
>>> Hi
>>>
>>> Without doing a bunch of actual *work* I’m not sure what is inside 
>>> the guts of the board. Being
>>> lazy I’ll just guess ….
>>>
>>> There appears to be a 10 MHz time base input and a pair of measurement 
>>> inputs. In a lot us will
>>> be comparing to a “house standard�. That standard has a pps 
>>> output that is related directly to
>>> the 10 MHz reference. If I can uniquely identify one edge (out of 10 
>>> million edges) as the right
>>> edge, I can use the 10 MHz as my pps reference. Put another way, I 
>>> don’t really need to measure
>>> a pps input from the house standard if I’m already locked up in 
>>> phase to the 10 MHz. All I need to
>>> do is to tag an edge / reset a counter.
>>>
>>> The advantage of this is that I may not need another fancy TDC chip to set 
>>> up the reference. I can
>>> use *both* inputs for DUT’s rather than using one as a reference.
>>>
>>> Part of the reason I’m guessing this would work is the claim that 
>>> boards can be stacked for multiple
>>> input setups ….
>>>
>>> Bob
>>>
 On Nov 27, 2016, at 

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[John Ackermann N8UR]

Hi Bob --

It's certainly possible to synchronize the TICC timescale epoch to an 
external pulse at startup.  The external sync pulse would have to 
simultaneously reset (a) the picDIV and (b) the coarse (100us) counter 
in the Arduino. The signals to do that are available, so it's a 
worthwhile experiment.


I have to think through whether there are any other gotchas but I'm 
pretty sure that you would not get closer than a few hundred nanoseconds 
given how closely the picDIV can sync -- I think Tom specifies that it's 
within 4 clocks, or 400 ns.


(Now, syncing two TICCs to each other is a different matter because 
there we one unit is master and provides the coarse clock directly to 
the slave; if both units are run from the same 10 MHz clock they should 
align within one 10 MHz tick.)


John


On 11/27/2016 12:26 PM, Bob Camp wrote:

Hi

Ok, so the guess was fairly close :)

How about a connector to allow an external PPS to reset the internal 10 MHz 
divider? That way all
the data is “in sync� with the house standard. If I want to know that my 
GPSDO is +32.751 ns off from
the house standard, I just look at the data on a terminal program …

Or am I missing something really obvious (again)?

Bob


On Nov 27, 2016, at 10:04 AM, John Ackermann N8UR  wrote:

Good guess.  The 10 MHz reference drives all the logic on the board, and 
particularly the counter that maintains a local timescale in 100us increments; 
the TDC7200 interpolates between the 100us ticks to stamp incoming events on 
channel A and/or B with picosecond precision.  The stamps on both channels are 
referenced to the same local timescale.

Therefore, you can do a measurement of a PPS source against the 10 MHz 
reference and the resulting timestamp output can be processed by TimeLab or 
whatever into stability data (the requirement being that the software knows how 
to deal with timestamps that increment by the nominal measurement rate, e.g., 1 
second per measurement for PPS data).

So with PPS from GPSDO "A" on channel A the timestamp output after unwrapping 
will show the phase of A vs. 10 MHz.

You can add PPS from GPSDO "B" on channel B and the TICC will also output 
timestamps of B vs. the 10 MHz source.

If you want, you can subtract A from B to get the time interval between the two 
GPSDO, since both timestamp measurements are against a common timescale.  The 
TICC has a mode to output the (B-A) difference, so it can act as either a 
traditional time interval counter, or as a two-channel timestamping counter.

And as noted in my other message to Luciano, the TICC can also output both 
timestamp and time interval data simultaneously to allow three-corner-hat 
measurements of (A-C, B-C, B-A) where C is the 10 MHz reference.

John


On 11/27/2016 09:24 AM, Bob Camp wrote:

Hi

Without doing a bunch of actual *work* I’m not sure what is inside the 
guts of the board. Being
lazy I’ll just guess ….

There appears to be a 10 MHz time base input and a pair of measurement inputs. 
In a lot us will
be comparing to a “house standard�. That standard has a pps output 
that is related directly to
the 10 MHz reference. If I can uniquely identify one edge (out of 10 million 
edges) as the right
edge, I can use the 10 MHz as my pps reference. Put another way, I don’t 
really need to measure
a pps input from the house standard if I’m already locked up in phase to 
the 10 MHz. All I need to
do is to tag an edge / reset a counter.

The advantage of this is that I may not need another fancy TDC chip to set up 
the reference. I can
use *both* inputs for DUT’s rather than using one as a reference.

Part of the reason I’m guessing this would work is the claim that boards 
can be stacked for multiple
input setups ….

Bob


On Nov 27, 2016, at 7:36 AM, timeok  wrote:


   Hi John,
I have planned to buy two TICC.
An interesting feature would be to be able to do two simultaneous acquisitions,
and Timelab as real time display,using the two indipendent input channels and 
the 10Mhz clock as single reference.
Luciano
www.timeok.it


   From "time-nuts" time-nuts-boun...@febo.com
   To "Discussion of precise time and frequency measurement" time-nuts@febo.com
   Cc
   Date Wed, 23 Nov 2016 10:48:57 -0500
   Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
   Counters with resolution below 1 nanosecond are difficult. They require
   either outrageous clock speeds, or interpolators that are typically a
   bunch of analog components mixed with black magic and stirred by
   frequent calibration. The very best single-shot resolution that's been
   commercially available is 22 picoseconds in the HP 5370A/B, with jitter
   somewhat more than that. My 5370B has an one-second noise ADEV of about
   4x10e-11.

   With the help of some very talented friends, I've been working on a new
   counter called the "TICC" with <60ps resolution and 

[time-nuts] FS: HP Z3801A

[Joseph Gray]

I'm selling my remaining Z3801A. Months ago, I replaced the original
GPS module with a more sensitive Oncore VP. At that time, I also
replaced several suspect capacitors on the DC-DC converter board.
Everything has been 100% since. The RS-232 mod was done long ago.

A serial cable and a 24 VDC power supply is included. I will also
include a spare Oncore VP module for free. Asking $300 plus
shipping/insurance.

I also have an HP 58516A 4-way GPS splitter that I will include for $50 more.

Joe Gray
W5JG
___
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[Bob Camp]

Hi

Ok, so the guess was fairly close :)

How about a connector to allow an external PPS to reset the internal 10 MHz 
divider? That way all
the data is “in sync” with the house standard. If I want to know that my GPSDO 
is +32.751 ns off from
the house standard, I just look at the data on a terminal program …

Or am I missing something really obvious (again)? 

Bob

> On Nov 27, 2016, at 10:04 AM, John Ackermann N8UR  wrote:
> 
> Good guess.  The 10 MHz reference drives all the logic on the board, and 
> particularly the counter that maintains a local timescale in 100us 
> increments; the TDC7200 interpolates between the 100us ticks to stamp 
> incoming events on channel A and/or B with picosecond precision.  The stamps 
> on both channels are referenced to the same local timescale.
> 
> Therefore, you can do a measurement of a PPS source against the 10 MHz 
> reference and the resulting timestamp output can be processed by TimeLab or 
> whatever into stability data (the requirement being that the software knows 
> how to deal with timestamps that increment by the nominal measurement rate, 
> e.g., 1 second per measurement for PPS data).
> 
> So with PPS from GPSDO "A" on channel A the timestamp output after unwrapping 
> will show the phase of A vs. 10 MHz.
> 
> You can add PPS from GPSDO "B" on channel B and the TICC will also output 
> timestamps of B vs. the 10 MHz source.
> 
> If you want, you can subtract A from B to get the time interval between the 
> two GPSDO, since both timestamp measurements are against a common timescale.  
> The TICC has a mode to output the (B-A) difference, so it can act as either a 
> traditional time interval counter, or as a two-channel timestamping counter.
> 
> And as noted in my other message to Luciano, the TICC can also output both 
> timestamp and time interval data simultaneously to allow three-corner-hat 
> measurements of (A-C, B-C, B-A) where C is the 10 MHz reference.
> 
> John
> 
> 
> On 11/27/2016 09:24 AM, Bob Camp wrote:
>> Hi
>> 
>> Without doing a bunch of actual *work* I’m not sure what is inside the 
>> guts of the board. Being
>> lazy I’ll just guess ….
>> 
>> There appears to be a 10 MHz time base input and a pair of measurement 
>> inputs. In a lot us will
>> be comparing to a “house standard�. That standard has a pps output that 
>> is related directly to
>> the 10 MHz reference. If I can uniquely identify one edge (out of 10 million 
>> edges) as the right
>> edge, I can use the 10 MHz as my pps reference. Put another way, I don’t 
>> really need to measure
>> a pps input from the house standard if I’m already locked up in phase to 
>> the 10 MHz. All I need to
>> do is to tag an edge / reset a counter.
>> 
>> The advantage of this is that I may not need another fancy TDC chip to set 
>> up the reference. I can
>> use *both* inputs for DUT’s rather than using one as a reference.
>> 
>> Part of the reason I’m guessing this would work is the claim that boards 
>> can be stacked for multiple
>> input setups ….
>> 
>> Bob
>> 
>>> On Nov 27, 2016, at 7:36 AM, timeok  wrote:
>>> 
>>> 
>>>   Hi John,
>>> I have planned to buy two TICC.
>>> An interesting feature would be to be able to do two simultaneous 
>>> acquisitions,
>>> and Timelab as real time display,using the two indipendent input channels 
>>> and the 10Mhz clock as single reference.
>>> Luciano
>>> www.timeok.it
>>> 
>>> 
>>>   From "time-nuts" time-nuts-boun...@febo.com
>>>   To "Discussion of precise time and frequency measurement" 
>>> time-nuts@febo.com
>>>   Cc
>>>   Date Wed, 23 Nov 2016 10:48:57 -0500
>>>   Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
>>>   Counters with resolution below 1 nanosecond are difficult. They require
>>>   either outrageous clock speeds, or interpolators that are typically a
>>>   bunch of analog components mixed with black magic and stirred by
>>>   frequent calibration. The very best single-shot resolution that's been
>>>   commercially available is 22 picoseconds in the HP 5370A/B, with jitter
>>>   somewhat more than that. My 5370B has an one-second noise ADEV of about
>>>   4x10e-11.
>>> 
>>>   With the help of some very talented friends, I've been working on a new
>>>   counter called the "TICC" with <60ps resolution and similar jitter,
>>>   based the Texas Instruments TDC7200 time-to-data-converter chip. The
>>>   noise ADEV is about 7x10e-11, not much worse than the 5370,
>>>   but here's the trick: the TICC is an Arduino shield (mounting a Mega
>>>   2560 controller) that weighs a couple of ounces, requires *no*
>>>   calibration, and is powered from a USB cable!
>>> 
>>>   The TICC is implemented as a two-channel timestamping counter. That
>>>   means it can measure or two low-frequency (e.g., pulse-per-second)
>>>   inputs against an external 10 MHz reference, or it can do a traditional
>>>   time interval measurement of input against the other. It can also
>>>   

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[John Ackermann N8UR]

Good guess.  The 10 MHz reference drives all the logic on the board, and 
particularly the counter that maintains a local timescale in 100us 
increments; the TDC7200 interpolates between the 100us ticks to stamp 
incoming events on channel A and/or B with picosecond precision.  The 
stamps on both channels are referenced to the same local timescale.


Therefore, you can do a measurement of a PPS source against the 10 MHz 
reference and the resulting timestamp output can be processed by TimeLab 
or whatever into stability data (the requirement being that the software 
knows how to deal with timestamps that increment by the nominal 
measurement rate, e.g., 1 second per measurement for PPS data).


So with PPS from GPSDO "A" on channel A the timestamp output after 
unwrapping will show the phase of A vs. 10 MHz.


You can add PPS from GPSDO "B" on channel B and the TICC will also 
output timestamps of B vs. the 10 MHz source.


If you want, you can subtract A from B to get the time interval between 
the two GPSDO, since both timestamp measurements are against a common 
timescale.  The TICC has a mode to output the (B-A) difference, so it 
can act as either a traditional time interval counter, or as a 
two-channel timestamping counter.


And as noted in my other message to Luciano, the TICC can also output 
both timestamp and time interval data simultaneously to allow 
three-corner-hat measurements of (A-C, B-C, B-A) where C is the 10 MHz 
reference.


John


On 11/27/2016 09:24 AM, Bob Camp wrote:

Hi

Without doing a bunch of actual *work* I’m not sure what is inside the guts 
of the board. Being
lazy I’ll just guess ….

There appears to be a 10 MHz time base input and a pair of measurement inputs. 
In a lot us will
be comparing to a “house standard�. That standard has a pps output that is 
related directly to
the 10 MHz reference. If I can uniquely identify one edge (out of 10 million 
edges) as the right
edge, I can use the 10 MHz as my pps reference. Put another way, I don’t 
really need to measure
a pps input from the house standard if I’m already locked up in phase to the 
10 MHz. All I need to
do is to tag an edge / reset a counter.

The advantage of this is that I may not need another fancy TDC chip to set up 
the reference. I can
use *both* inputs for DUT’s rather than using one as a reference.

Part of the reason I’m guessing this would work is the claim that boards can 
be stacked for multiple
input setups ….

Bob


On Nov 27, 2016, at 7:36 AM, timeok  wrote:


   Hi John,
I have planned to buy two TICC.
An interesting feature would be to be able to do two simultaneous acquisitions,
and Timelab as real time display,using the two indipendent input channels and 
the 10Mhz clock as single reference.
Luciano
www.timeok.it


   From "time-nuts" time-nuts-boun...@febo.com
   To "Discussion of precise time and frequency measurement" time-nuts@febo.com
   Cc
   Date Wed, 23 Nov 2016 10:48:57 -0500
   Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
   Counters with resolution below 1 nanosecond are difficult. They require
   either outrageous clock speeds, or interpolators that are typically a
   bunch of analog components mixed with black magic and stirred by
   frequent calibration. The very best single-shot resolution that's been
   commercially available is 22 picoseconds in the HP 5370A/B, with jitter
   somewhat more than that. My 5370B has an one-second noise ADEV of about
   4x10e-11.

   With the help of some very talented friends, I've been working on a new
   counter called the "TICC" with <60ps resolution and similar jitter,
   based the Texas Instruments TDC7200 time-to-data-converter chip. The
   noise ADEV is about 7x10e-11, not much worse than the 5370,
   but here's the trick: the TICC is an Arduino shield (mounting a Mega
   2560 controller) that weighs a couple of ounces, requires *no*
   calibration, and is powered from a USB cable!

   The TICC is implemented as a two-channel timestamping counter. That
   means it can measure or two low-frequency (e.g., pulse-per-second)
   inputs against an external 10 MHz reference, or it can do a traditional
   time interval measurement of input against the other. It can also
   measure period, ratio, or any other function of two-channel timestamp
   data. (And by the way -- multiple TICCs can be connected to yield 4, 6,
   8, or more synchronized channels, though we haven't tested this
   capability yet.)

   I've attached a picture of the TICC prototype as well as an ADEV plot of
   a 17+ day run of multiple measurements taken by two TICCs, and also
   showing the TICC noise floor. The good news behind that plot is that
   there are more than 6 million data points behind these results, and
   there was not a single glitch or significant outlier among them.

   There's more information available at http://febo.com/pages/TICC

   The software is open source (BSD license) and is 

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[John Ackermann N8UR]

Hi Luciano --

Glad to hear that!

The capability you asked for already exists (great minds think alike...)

In timestamp mode, the TICC will output the stamps for each channel 
independently, measured against the common 10 MHz reference.  So if both 
channels are active, you'll see a bunch of lines something like:


1.234567891234 chA
1.234567892345 chB
2.234567890434 chA
2.234567892789 chB

Recent beta versions of TimeLab can acquire multiple channels on a 
single serial port; there are a couple of magic setup commands in the 
"Acquire" dialog that will allow TimeLab to receive the above and 
display it as two separate traces.


There is also a three-cornered-hat capability, though it's a bit of a 
hack.  The TICC has a "TimeLab" mode which will output two timestamps as 
above, but in addition "chC" which is the time interval (B-A).


Since TimeLab requires all the input signals to be in the same format, 
the chC output is munged into a fake timestamp like this (adding the 
integer part of chB to the B-A difference):


1.234567891234 chA
1.234567892345 chB
1. chC
2.234567890434 chA
2.234567892789 chB
2.2355 chC

With both TICC and TimeLab configured this way, you can do 
three-cornered-hat measurements in real time, which is pretty cool.


When I get a chance, I'll document the setup for this in the TICC 
operation manual.


John

On 11/27/2016 07:36 AM, timeok wrote:


Hi John,
I have planned to buy two TICC.
An interesting feature would be to be able to do two simultaneous acquisitions,
and Timelab as real time display,using the two indipendent input channels and 
the 10Mhz clock as single reference.
Luciano
www.timeok.it


From "time-nuts" time-nuts-boun...@febo.com
To "Discussion of precise time and frequency measurement" time-nuts@febo.com
Cc
Date Wed, 23 Nov 2016 10:48:57 -0500
Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
Counters with resolution below 1 nanosecond are difficult. They require
either outrageous clock speeds, or interpolators that are typically a
bunch of analog components mixed with black magic and stirred by
frequent calibration. The very best single-shot resolution that's been
commercially available is 22 picoseconds in the HP 5370A/B, with jitter
somewhat more than that. My 5370B has an one-second noise ADEV of about
4x10e-11.

With the help of some very talented friends, I've been working on a new
counter called the "TICC" with <60ps resolution and similar jitter,
based the Texas Instruments TDC7200 time-to-data-converter chip. The
noise ADEV is about 7x10e-11, not much worse than the 5370,
but here's the trick: the TICC is an Arduino shield (mounting a Mega
2560 controller) that weighs a couple of ounces, requires *no*
calibration, and is powered from a USB cable!

The TICC is implemented as a two-channel timestamping counter. That
means it can measure or two low-frequency (e.g., pulse-per-second)
inputs against an external 10 MHz reference, or it can do a traditional
time interval measurement of input against the other. It can also
measure period, ratio, or any other function of two-channel timestamp
data. (And by the way -- multiple TICCs can be connected to yield 4, 6,
8, or more synchronized channels, though we haven't tested this
capability yet.)

I've attached a picture of the TICC prototype as well as an ADEV plot of
a 17+ day run of multiple measurements taken by two TICCs, and also
showing the TICC noise floor. The good news behind that plot is that
there are more than 6 million data points behind these results, and
there was not a single glitch or significant outlier among them.

There's more information available at http://febo.com/pages/TICC

The software is open source (BSD license) and is available at
https://github.com/TAPR/TICC -- the current version seems be reliable
but there are still features to add and a *lot* of cleanup to do; it's
currently ugly and very much a work in process.

As always, I'll be making the TICC available through TAPR. We're still
finalizing details, but we expect the price to be less than $200 for a
turn-key system: TICC mounted an Arduino with software loaded and
tested for basic functionality. We hope to ship the TICC by February.

I'll post a note in a week or two with final price and ordering
information. As a heads up, we will probably offer a small discount for
pre-orders. TAPR is a shoestring non-profit group and the up-front cost
to manufacture this unit will frankly be a challenge for us. Getting
pre-orders will help our cash flow significantly, so we ask you to keep
that in mind.

John
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Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[Bob Camp]

Hi

Without doing a bunch of actual *work* I’m not sure what is inside the guts of 
the board. Being 
lazy I’ll just guess ….

There appears to be a 10 MHz time base input and a pair of measurement inputs. 
In a lot us will 
be comparing to a “house standard”. That standard has a pps output that is 
related directly to 
the 10 MHz reference. If I can uniquely identify one edge (out of 10 million 
edges) as the right 
edge, I can use the 10 MHz as my pps reference. Put another way, I don’t really 
need to measure
a pps input from the house standard if I’m already locked up in phase to the 10 
MHz. All I need to
do is to tag an edge / reset a counter. 

The advantage of this is that I may not need another fancy TDC chip to set up 
the reference. I can
use *both* inputs for DUT’s rather than using one as a reference.

Part of the reason I’m guessing this would work is the claim that boards can be 
stacked for multiple 
input setups ….

Bob

> On Nov 27, 2016, at 7:36 AM, timeok  wrote:
> 
> 
>   Hi John,
> I have planned to buy two TICC.
> An interesting feature would be to be able to do two simultaneous 
> acquisitions,
> and Timelab as real time display,using the two indipendent input channels and 
> the 10Mhz clock as single reference.
> Luciano
> www.timeok.it
> 
> 
>   From "time-nuts" time-nuts-boun...@febo.com
>   To "Discussion of precise time and frequency measurement" time-nuts@febo.com
>   Cc
>   Date Wed, 23 Nov 2016 10:48:57 -0500
>   Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
>   Counters with resolution below 1 nanosecond are difficult. They require
>   either outrageous clock speeds, or interpolators that are typically a
>   bunch of analog components mixed with black magic and stirred by
>   frequent calibration. The very best single-shot resolution that's been
>   commercially available is 22 picoseconds in the HP 5370A/B, with jitter
>   somewhat more than that. My 5370B has an one-second noise ADEV of about
>   4x10e-11.
> 
>   With the help of some very talented friends, I've been working on a new
>   counter called the "TICC" with <60ps resolution and similar jitter,
>   based the Texas Instruments TDC7200 time-to-data-converter chip. The
>   noise ADEV is about 7x10e-11, not much worse than the 5370,
>   but here's the trick: the TICC is an Arduino shield (mounting a Mega
>   2560 controller) that weighs a couple of ounces, requires *no*
>   calibration, and is powered from a USB cable!
> 
>   The TICC is implemented as a two-channel timestamping counter. That
>   means it can measure or two low-frequency (e.g., pulse-per-second)
>   inputs against an external 10 MHz reference, or it can do a traditional
>   time interval measurement of input against the other. It can also
>   measure period, ratio, or any other function of two-channel timestamp
>   data. (And by the way -- multiple TICCs can be connected to yield 4, 6,
>   8, or more synchronized channels, though we haven't tested this
>   capability yet.)
> 
>   I've attached a picture of the TICC prototype as well as an ADEV plot of
>   a 17+ day run of multiple measurements taken by two TICCs, and also
>   showing the TICC noise floor. The good news behind that plot is that
>   there are more than 6 million data points behind these results, and
>   there was not a single glitch or significant outlier among them.
> 
>   There's more information available at http://febo.com/pages/TICC
> 
>   The software is open source (BSD license) and is available at
>   https://github.com/TAPR/TICC -- the current version seems be reliable
>   but there are still features to add and a *lot* of cleanup to do; it's
>   currently ugly and very much a work in process.
> 
>   As always, I'll be making the TICC available through TAPR. We're still
>   finalizing details, but we expect the price to be less than $200 for a
>   turn-key system: TICC mounted an Arduino with software loaded and
>   tested for basic functionality. We hope to ship the TICC by February.
> 
>   I'll post a note in a week or two with final price and ordering
>   information. As a heads up, we will probably offer a small discount for
>   pre-orders. TAPR is a shoestring non-profit group and the up-front cost
>   to manufacture this unit will frankly be a challenge for us. Getting
>   pre-orders will help our cash flow significantly, so we ask you to keep
>   that in mind.
> 
>   John
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Re: [time-nuts] Trimble 65256 OCXO

[Bob Camp]

Hi

Pin 5 is the EFC reference pin. It may (or may not) have a voltage on it. If 
there is a 
voltage on it, it’s a voltage that the original OEM customer found useful. It 
may (or may not)
have a series resistor to match up with an OEM specified trim pot.

Bob

> On Nov 27, 2016, at 2:04 AM, Dave Brown  wrote:
> 
> This 10 MHz unit has a 5th pin that I can't find any documentation about. 
> There have been posts in the past that have also indicated its use is 
> unknown.  Looking at the base, the four connections in the corners are known 
> quantities. (ground, EFC, 10 MHz out and + supply) No. 5 is midway along one 
> side.
> I thought it may be a reference supply for the EFC pin- with a 12.03 volt 
> supply the unknown pin measures at 2.803 volts-which is usefully above the 
> required EFC voltage ( ~2.4 volts) to bring it on frequency.
> But does anyone have some hard data on this 'unknown' pin?
> DaveB, NZ
> 
> 
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Re: [time-nuts] UCCM arrived

[Bob Camp]

Hi

You have a system with cascaded gains and noise figures. The “front end” of the 
GPSDO is 
in the antenna. The cable is between the front end of the receiver and the rest 
of the “radio”. 
With a cascaded noise figure situation, as long as the noise figure of the 
first stage is low (it is)
and the gain of the first stage is high (it is) and the noise of the next stage 
(in the GPSDO) isn’t 
awful (it’s not) there is no problem. The gain of the antenna is specified so 
you know what that is.
If the cable loss is less than the gain by about 6 db, there is little impact. 
In this case “little” means
that you can’t measure what the impact is. Since you have a 26 db antenna, the 
cable loss needs 
to be less than 20 db. If you can get it down to 16 db that would give you a 
bit of margin.

Bob


> On Nov 27, 2016, at 2:01 AM, David J Taylor  
> wrote:
> 
> Hello to all,
> 
> I connected the unit to a 11m of H-155 cable(assumed 4.79dB loss "worst case" 
> at 1.5GHz), thrown the GPS antenna on the balcony horizontally and this is 
> what I got:
> []
> - Given the attenuation (less than 5 dB) do I really need to change the cable 
> for something better?
> []
> Giuseppe Marullo
> IW2JWW - JN45RQ
> =
> 
> Giuseppe,
> 
> Most GPS antennas have an LNA built-in, making cable loss less significant. 
> Doesn't your antenna have that?
> 
> 73,
> David GM8ARV
> -- 
> SatSignal Software - Quality software written to your requirements
> Web: http://www.satsignal.eu
> Email: david-tay...@blueyonder.co.uk
> Twitter: @gm8arv 
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Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

[timeok]

   Hi John,
I have planned to buy two TICC.
An interesting feature would be to be able to do two simultaneous acquisitions,
and Timelab as real time display,using the two indipendent input channels and 
the 10Mhz clock as single reference.
Luciano
www.timeok.it


   From "time-nuts" time-nuts-boun...@febo.com
   To "Discussion of precise time and frequency measurement" time-nuts@febo.com
   Cc
   Date Wed, 23 Nov 2016 10:48:57 -0500
   Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
   Counters with resolution below 1 nanosecond are difficult. They require
   either outrageous clock speeds, or interpolators that are typically a
   bunch of analog components mixed with black magic and stirred by
   frequent calibration. The very best single-shot resolution that's been
   commercially available is 22 picoseconds in the HP 5370A/B, with jitter
   somewhat more than that. My 5370B has an one-second noise ADEV of about
   4x10e-11.

   With the help of some very talented friends, I've been working on a new
   counter called the "TICC" with <60ps resolution and similar jitter,
   based the Texas Instruments TDC7200 time-to-data-converter chip. The
   noise ADEV is about 7x10e-11, not much worse than the 5370,
   but here's the trick: the TICC is an Arduino shield (mounting a Mega
   2560 controller) that weighs a couple of ounces, requires *no*
   calibration, and is powered from a USB cable!

   The TICC is implemented as a two-channel timestamping counter. That
   means it can measure or two low-frequency (e.g., pulse-per-second)
   inputs against an external 10 MHz reference, or it can do a traditional
   time interval measurement of input against the other. It can also
   measure period, ratio, or any other function of two-channel timestamp
   data. (And by the way -- multiple TICCs can be connected to yield 4, 6,
   8, or more synchronized channels, though we haven't tested this
   capability yet.)

   I've attached a picture of the TICC prototype as well as an ADEV plot of
   a 17+ day run of multiple measurements taken by two TICCs, and also
   showing the TICC noise floor. The good news behind that plot is that
   there are more than 6 million data points behind these results, and
   there was not a single glitch or significant outlier among them.

   There's more information available at http://febo.com/pages/TICC

   The software is open source (BSD license) and is available at
   https://github.com/TAPR/TICC -- the current version seems be reliable
   but there are still features to add and a *lot* of cleanup to do; it's
   currently ugly and very much a work in process.

   As always, I'll be making the TICC available through TAPR. We're still
   finalizing details, but we expect the price to be less than $200 for a
   turn-key system: TICC mounted an Arduino with software loaded and
   tested for basic functionality. We hope to ship the TICC by February.

   I'll post a note in a week or two with final price and ordering
   information. As a heads up, we will probably offer a small discount for
   pre-orders. TAPR is a shoestring non-profit group and the up-front cost
   to manufacture this unit will frankly be a challenge for us. Getting
   pre-orders will help our cash flow significantly, so we ask you to keep
   that in mind.

   John
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Re: [time-nuts] UCCM arrived

[giuseppe]

>Most GPS antennas have an LNA built-in, making cable loss less significant. 
>Doesn't your antenna have that?
Sure, specs says:
- Amplifier Gain: 26 dB +/- 3 dB
- Maximum Noise Figure:≤ 2.5 dB @ +25°C including pre-selector
I still have to search a command to check signal strength. 

>For a long term installation, an antenna location that will “see” more sat’s 
>is a really good idea.
>
>Bob 
Antenna was on the balcony at first floor (european, 2nd floor us) on the 
balcony, laid there horizontally. Frankly I was not even expecting it to work 
at all, LOL!  
With a ten feet mast I was able to get eight-nine satellites before having to 
disconnect it.

A little higher and it should have a perfect sky clearance (a little bit more 
cable will be needed though, hence the question about length).

Giuseppe Marullo
IW2JWW - JN45RQ 
 


From: "time-nuts" time-nuts-boun...@febo.com
To: time-nuts@febo.com
Cc: 
Date: Sun, 27 Nov 2016 07:01:05 -
Subject: Re: [time-nuts] UCCM arrived


Hello to all,
 
I connected the unit to a 11m of H-155 cable(assumed 4.79dB loss "worst 
case" at 1.5GHz), thrown the GPS antenna on the balcony horizontally and 
this is what I got:
[]
- Given the attenuation (less than 5 dB) do I really need to change the 
cable for something better?
[]
Giuseppe Marullo
IW2JWW - JN45RQ
=
 
Giuseppe,
 
Most GPS antennas have an LNA built-in, making cable loss less significant. 
Doesn't your antenna have that?
 
73,
David GM8ARV
-- 
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
Twitter: @gm8arv 
 
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Re: [time-nuts] Trimble 65256 OCXO

[Hal Murray]

tract...@ihug.co.nz said:
>  I thought it may be a reference supply for the EFC pin- with a 12.03 volt
> supply the unknown pin measures at 2.803 volts-which is usefully above the
> required EFC voltage ( ~2.4 volts) to bring it on frequency.
>  But does anyone have some hard data on this 'unknown' pin? 

Is it input or output?  What happens if you pull it to ground with a 10K or 
1K resistor?  Or measure the impedance when powered off.

2.8 volts seems a bit low to be a useful supply.


-- 
These are my opinions.  I hate spam.



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