[time-nuts] A counter for phase measures

[Bob Camp]

Hi

If you want Adev of < 1.0 x 10^-11 at a tau of 1 second, then a counter
probably is not going to do it for you. To do a reasonable job on "time nut"
grade stuff you probably want something with a floor of < 1.0 x 10^-13 at a
tau of 1 second. 

You have several choices:

1) Forget about 1 second and move out to 100 seconds. At that point your
53132's and the like will do ok. Their resolution goes up as the time gets
longer.

2) If you are measuring pps's go over to something like a Wavecrest.

3) If you are looking at 10 MHz either go to a DMTD or a TimePod. 

In all cases, the gizmo it's self just takes data. The PC does the heavy
lifting of turning into pretty plots. You can get sort of plots on things
like a CNT-90 or a 5371, but the PC does a much better job.

Bob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Volker Esper
Sent: Friday, November 02, 2012 11:32 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] A counter for phase measures

Dear fellows,

I'm searching for a counter that allows me to make automated measure 
series. Of course, Allan Deviation is an important thing to determine 
when experimenting with or developing GPSDOs (what I intend). So it 
seemed to be a nice thing to measure phase deviation with a counter (HP 
53132A or SR-620 or so).

When experimenting with that stuff I discovered, that all my equipment 
would not be adequate to determine Allan Deviations beyond 10e-11 (or 
so). The question is, can any counter deliver that precision / low noise 
to make such measurements possible? Or does it have to be a more 
sophisticated technique, such as cross spectrum analysis?

Thanks a lot in advance

Volker

(I guess you recognize, that I am just a newbie to that all)