[time-nuts] How to measure Allan Deviation?

[Didier Juges]

Here are my $0.02...

Magnus Danielson wrote:
> From: Dr Bruce Griffiths <bruce.griffiths at xtra.co.nz>
> Subject: Re: [time-nuts] How to measure Allan Deviation?
> Date: Tue, 24 Oct 2006 10:52:21 +1300
> Message-ID: <453D3995.8080004 at xtra.co.nz>
>
>   
>> Tom
>>     
>
> Hi Bruce,
>
>   
>> In comparing 2 oscillators do you mean
>>
>> 1) Connecting one oscillator to the FREQ STD input at the rear of the 
>> 5370A, selecting the external timebase and connecting the other 
>> oscillator to the Front panel FREQ/PERIOD input and then selecting 
>> frequency measurement which in effect gives the frequency ratio of the 2 
>> oscillators?
>>     
>
> I have advocated this approach, but nobody seemed to care.
>
>   
HP says in the 5316B manual (probably in other manuals, but that's where 
I saw it first), that it is best to compare 2 oscillators by plugging 
them in START and STOP respectively, but NOT to use one as a standard, 
because averaging works better (or simply, works) when the internal 
standard is async with either START or STOP signals.
> Cheers,
> Magnus
>   

Didier