[time-nuts] TIC Characterization

[Poul-Henning Kamp]

--------
In message <e2141e96-9c20-02f0-3225-e228b56763f6 at rubidium.dyndns.org>, Magnus D
anielson writes:
>Hi Gilles,
>
>On 12/29/18 11:28 PM, Club-Internet Clemgill wrote:
>> Hi, 
>> Looking to testing my HP53132A in TIC mode. 
>> I considered the Time Interval measurement technique: 
>> The start channel is connected to a 1 PPS signal, and to the stop channel though a coax cable (constant delay line).
>
>Fair enough setup. This is a static test setup which works as long as
>you do not lock the counter up to a 10 MHz of the same source as the
>PPS, and for all maters not accurate enough, so it's best for the test
>for it to be free-running.

Here is another test-setup, which is very revealing about non-white
noise in TIC counters:

You need a signal generator which can be locked to an external
frequency and control the phase of the output signal relative to
that external frequency.  The HP3336 is a good cancidate.

Lock both the counter under investigation and the siggen to the
same house standard.  Set the siggen to output same frequency as
house standard.

measure (start=house_std, stop=siggen) and (start=siggen, stop=house_std) for
as many siggen phase settings as you have patience for.

Plot results, and wonder why you don't get a straight line...

-- 
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.