[time-nuts] Commercial software defined radio for clock metrology

[Attila Kinali]

On Sat, 28 May 2016 08:47:45 +0000 (UTC)
Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

> This SDR setup appears to have a higher PN (at least 2 ADC's per signal
> are required  to achieve lower PN ) than a Timepod, however it appears
> to be better at measuring ADEV than a Timepod.

Yes, the spec'ed SNR of the ADS62P44 is 74dBFS (typ) while the LTC2216
is spec'ed with 81dBFS (typ). Additionally, the input amplitudes in
Sherman and Jördens experiments were kept around half scale, which is
another -6dB in SNR. There is another ~15dB in difference, but I currently
don't see where it comes from.


What I wonder is, what the TDEV performance of the TimePod is, given
that it uses single channel ADCs. Unfortunately, there is nothing in the spec.

Guestimating from the ADEV specs, it looks like that the TimePod has about
the performance of the single channel setup. Which approximately makes sense.

			Attila Kinali

-- 
Reading can seriously damage your ignorance.
		-- unknown