Re: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters

[Magnus Danielson]

Hi,

The J06 P-59992A time interval calibrator is not only there to calibrate 
time offsets, but also offsets in trigger point. HP has a nice patent 
which describes it all.


I also got one, found it on ebay.

Cheers,
Magnus

On 07/09/2017 01:18 AM, Bob kb8tq wrote:

Hi

Good means whatever the 5313x needs for calibration. If that is four signals 
that are
crossing zero within < 10 ps of the “correct time” then that is the definition 
of good in this case.

Rise time delay, fall time delay are rarely the same in logic gates. 
Propagation inside a chip to
point A may well be different by nanoseconds relative to the propagation to a 
very similar
point B. All of that would mess up a signal that *might* need to be 50/50 to 
within 10 ps  or
a second signal that must cross zero half way in-between (also to within 10 ps).

If you want to have a lot of fun with this, pull out the timing analysis tool 
for your favorite
FPGA and start fiddling around.

Bob


On Jul 8, 2017, at 5:53 PM, Hal Murray  wrote:


t...@leapsecond.com said:

The PIC dividers are good to a couple ps. I suspect the larger issue is the
PCB and wiring design.


What does "good" mean?

I'd expect the variations due to power or temperature would be easy to
measure.

Delay through classic CMOS is linear with absolute temperature and inverse
linear with supply voltage.

The classic way to get time-nuts level noise on FPGA outputs is to wiggle a
nearby pin.   That shouldn't be a problem with a dedicated PIC but would
probably show up if you are generating multiple frequencies.


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Re: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters

[Bruce Griffiths]

The simplest solution to the divider and clock shaper is perhaps to use an 
LTC6954. The LTC6954 offers PECL/CMOS and LVDS outputs together with a low 
jitter (sub ps) programmable (SPI) divider (1-63).A couple of coax relays like 
those from Dow Key microwave together with some hardline and a couple of 
splitters could be used to implement the signal switching. 

> 
> On 09 July 2017 at 09:53 Hal Murray  wrote:
> 
> t...@leapsecond.com said:
> 
> > > 
> > The PIC dividers are good to a couple ps. I suspect the larger 
> > issue is the
> > PCB and wiring design.
> > 
> > > 
> What does "good" mean?
> 
> I'd expect the variations due to power or temperature would be easy to
> measure.
> 
> Delay through classic CMOS is linear with absolute temperature and inverse
> linear with supply voltage.
> 
> The classic way to get time-nuts level noise on FPGA outputs is to wiggle 
> a
> nearby pin. That shouldn't be a problem with a dedicated PIC but would
> probably show up if you are generating multiple frequencies.
> 
> --
> These are my opinions. I hate spam.
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to 
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> 
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Re: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters

[Bob kb8tq]

Hi

Good means whatever the 5313x needs for calibration. If that is four signals 
that are 
crossing zero within < 10 ps of the “correct time” then that is the definition 
of good in this case. 

Rise time delay, fall time delay are rarely the same in logic gates. 
Propagation inside a chip to
point A may well be different by nanoseconds relative to the propagation to a 
very similar 
point B. All of that would mess up a signal that *might* need to be 50/50 to 
within 10 ps  or 
a second signal that must cross zero half way in-between (also to within 10 
ps). 

If you want to have a lot of fun with this, pull out the timing analysis tool 
for your favorite
FPGA and start fiddling around.

Bob

> On Jul 8, 2017, at 5:53 PM, Hal Murray  wrote:
> 
> 
> t...@leapsecond.com said:
>> The PIC dividers are good to a couple ps. I suspect the larger issue is the
>> PCB and wiring design. 
> 
> What does "good" mean?
> 
> I'd expect the variations due to power or temperature would be easy to 
> measure.
> 
> Delay through classic CMOS is linear with absolute temperature and inverse 
> linear with supply voltage.
> 
> The classic way to get time-nuts level noise on FPGA outputs is to wiggle a 
> nearby pin.   That shouldn't be a problem with a dedicated PIC but would 
> probably show up if you are generating multiple frequencies.
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Re: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters

[Hal Murray]

t...@leapsecond.com said:
> The PIC dividers are good to a couple ps. I suspect the larger issue is the
> PCB and wiring design. 

What does "good" mean?

I'd expect the variations due to power or temperature would be easy to 
measure.

Delay through classic CMOS is linear with absolute temperature and inverse 
linear with supply voltage.

The classic way to get time-nuts level noise on FPGA outputs is to wiggle a 
nearby pin.   That shouldn't be a problem with a dedicated PIC but would 
probably show up if you are generating multiple frequencies.


-- 
These are my opinions.  I hate spam.



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Re: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters

[Bob kb8tq]

Hi

> On Jul 8, 2017, at 1:31 PM, Tom Van Baak <t...@leapsecond.com> wrote:
> 
> Mark writes:
> 
>> lots of luck finding one of those
> 
> Actually, you can get J06 HP-59992A calibrators on eBay. You might have to 
> wait a while but I've seen them frequently over time. Note that eBay has an 
> automatic search notification feature so you can get email when one shows up.
> 
> If you want I'll lend you one of my J06 HP-59992A for your calibration. 
> Contact me off-list.
> 
> Bob writes:
> 
>> If a few ns is “ok” it’s an easy task. If the spec is < 10 ps … not quite as 
>> easy. 
> 
> The PIC dividers are good to a couple ps. I suspect the larger issue is the 
> PCB and wiring design.

The jitter on the outputs is indeed good to that level. I’d be surprised if the 
“DC offset” is that good. 
Been wrong before …..

Why do I suspect that data will be forthcoming? :)

Bob


> 
> /tvb
> 
> - Original Message - 
> From: "Mark Sims" <hol...@hotmail.com>
> To: <time-nuts@febo.com>
> Sent: Saturday, July 08, 2017 6:31 AM
> Subject: [time-nuts] J06 HP-59992A time interval calibrator for 
> HP-531xxcounters
> 
> 
>> To do a full and proper calibration of the HP-53131/53132/53181 counters you 
>> need a J06 HP-59992A time interval calibrator... lots of luck finding one of 
>> those.   Looking at the manual, it is actually a fairly simple device which 
>> can be greatly simplified for the task of calibrating a 531XX counter.
>> 
>> The main task is to generate 10 MHz square waves with 50% duty cycle.  Four 
>> versions of the signal are generated (two positive and two with inverted 
>> phase).  One of four combos of these signals (P1-P2,  P2-P1,  N1-N2, and 
>> N2-N1) are driven to two output connectors.   The 59992A uses splitters and 
>> phase shifters to generate the signals and can handle analog signals.  The 
>> 531xx cal uses square waves so those signals can be generated digitally.   
>> 
>> My first idea is to take a 20 MHz oscillator and divide it by two to get a 
>> 50% duty cycle. One could also do something like squaring a 10 MHz osc with 
>> something like the Wenzel squarer... that would provide a more stable signal 
>> frequency wise but that might add some asymmetries to the signal.  Feeding 
>> the 10 Mhz osc through a doubler and dividing the squared signal might 
>> provide the best solution.
>> 
>> The 531xx cal procedure uses a +/- 0.50V signal.   I need a simple and cheap 
>> circuit to level shift the TTL signal to +/- 0.50V  It probably needs clean, 
>> stable, fast edges and able to drive a 50 ohm load (the manuals don't 
>> specify the required edge rates and load).   Any ideas for a suitable level 
>> shifter / buffer?  It would also be super nice if it could work from a 
>> single supply...
>> 
>> Also,  if such a cal board was laid out would there be any interest in 
>> making it available for others to build?  
> 
> 
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Re: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters

[Tom Van Baak]

Mark writes:

> lots of luck finding one of those

Actually, you can get J06 HP-59992A calibrators on eBay. You might have to wait 
a while but I've seen them frequently over time. Note that eBay has an 
automatic search notification feature so you can get email when one shows up.

If you want I'll lend you one of my J06 HP-59992A for your calibration. Contact 
me off-list.

Bob writes:

> If a few ns is “ok” it’s an easy task. If the spec is < 10 ps … not quite as 
> easy. 

The PIC dividers are good to a couple ps. I suspect the larger issue is the PCB 
and wiring design.

/tvb

- Original Message - 
From: "Mark Sims" <hol...@hotmail.com>
To: <time-nuts@febo.com>
Sent: Saturday, July 08, 2017 6:31 AM
Subject: [time-nuts] J06 HP-59992A time interval calibrator for HP-531xxcounters


> To do a full and proper calibration of the HP-53131/53132/53181 counters you 
> need a J06 HP-59992A time interval calibrator... lots of luck finding one of 
> those.   Looking at the manual, it is actually a fairly simple device which 
> can be greatly simplified for the task of calibrating a 531XX counter.
> 
> The main task is to generate 10 MHz square waves with 50% duty cycle.  Four 
> versions of the signal are generated (two positive and two with inverted 
> phase).  One of four combos of these signals (P1-P2,  P2-P1,  N1-N2, and 
> N2-N1) are driven to two output connectors.   The 59992A uses splitters and 
> phase shifters to generate the signals and can handle analog signals.  The 
> 531xx cal uses square waves so those signals can be generated digitally.   
> 
> My first idea is to take a 20 MHz oscillator and divide it by two to get a 
> 50% duty cycle. One could also do something like squaring a 10 MHz osc with 
> something like the Wenzel squarer... that would provide a more stable signal 
> frequency wise but that might add some asymmetries to the signal.  Feeding 
> the 10 Mhz osc through a doubler and dividing the squared signal might 
> provide the best solution.
> 
> The 531xx cal procedure uses a +/- 0.50V signal.   I need a simple and cheap 
> circuit to level shift the TTL signal to +/- 0.50V  It probably needs clean, 
> stable, fast edges and able to drive a 50 ohm load (the manuals don't specify 
> the required edge rates and load).   Any ideas for a suitable level shifter / 
> buffer?  It would also be super nice if it could work from a single supply...
> 
> Also,  if such a cal board was laid out would there be any interest in making 
> it available for others to build?  


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