[time-nuts] Divider pecking order ?

[Magnus Danielson]

Tom Van Baak wrote:
>> Group,
>>
>> If Dave P's current divider design has design jitter specs approaching
>> SOTA vvs cost levels whilst the TAPR board is (perhaps) slightly
>> inferior in performance, where does that leave Tom's venerable 1pps PIC
>> divider in the pecking order ?
>>
>> Will all designs be subjected to a "back-to-back" run-off sometime soon
>> ?  This would save us mere mortals without the means of verifying actual
>> jitter performance much angst and gnashing of teeth !
>>
>> Good work chaps.
>>
>> Kit
>> VK2LL
>
> Hi Kit,
>
> My guess is all of the dividers are more than good enough. But...
>
> Since the question of jitter comes up now and then, and since
> there are several new dividers in the queue this year, I thought
> I'd settle it once and for all and actually measure as many as I
> can find.
I think it would be a very good idea.
> An added bonus is that Magnus is able and willing to do the same
> and that means not only can we compare divider jitter but we can
> compare methods to measure divider jitter. In this field validating
> and comparing methods is as important as making measurements.
... and learn from each others methods and misstakes.
> As for pecking order? I don't really know yet. Wait to see if
> Peter picks a peck of pulsing picosecond PICs. 
We haven't settled the pecking order. To able able to do that we need to 
measure and compare.

After that we need to think. It might be that the off the shelf variant 
may have some design-issues, but some of them could be surprisingly 
simple to overcome by modification (say swapping drivers, disable 
signals etc).

So the final pecking order may not be put down after a day in either 
Toms or my lab. We would have initial results, but that's all.

Currently I have one assembled TADD-2, one not yeat assembled, and a 
HP5328A.

The HP5328A is not the same thing all the time. The input stage depends 
on the options it has. Plain HP5328A or having Option 040 or 041 is 
making a difference here.

If someone wants me to measure anything else, they would have to send it 
to me.

Also, I have some homework to do just to set up logging from any of my 
toys. I need to do that. Yes, I am lazy.

Cheers,
Magnus