[time-nuts] Why using HP5370 ext-ref is (maybe) a bad idea

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Mar 3 17:59:16 EST 2014

In message <531505BC.4050900 at rubidium.dyndns.org>, Magnus Danielson writes:
>On 03/03/14 22:35, Poul-Henning Kamp wrote:
>> In message <5314EF87.1020204 at rubidium.dyndns.org>, Magnus Danielson writes:

>Indeed. Let's assume that it's not the BBB causing the issue, but it's 
>inherent to the 5370 design.

Charles reminded me of this document in private email:


It explicitly mentions the 5370A, so I guess a check is in order
if the ...B has these changes already.

>>> Those with a high quality RF generator could force-feed a 200 MHz into
>>> the counter and see if it makes any major difference.
>> Yes, that would be an interesting experiment.
>It's a bit problematic thought, the signal is fed to three different 
>places, A19, A20 (the interpolators) and A22.

I would go for TP1 at A21 ?

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at 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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