[time-nuts] Misuse of word "decimate" (was Re: Short term 10MHz source)

[Dan Kemppainen]

Hi,

As I'm inclined pop my head up and throw my opinion in here...

Since the internal clock (ring oscillator) is essentially free running 
in the TDC7200 it really has a 55ps +/- xxx ps resolution. That is to 
say, it may be 55ns, or 55.001ns, or 54.999ns resolution. It's possible 
those extra digits may actually give meaningful data, so I'm inclined to 
suggest leaving the digits in there.

In any case, this discussion regarding the TICC/TDC7200 resolution and 
calibration process is probably helpful to many. I've picked up a few 
details in the last day or so.

Dan

On 1/10/2019 12:00 PM, time-nuts-request at lists.febo.com wrote:
> Date: Thu, 10 Jan 2019 07:54:20 -0500
> From: "John Ackermann.  N8UR"<jra at febo.com>
> To: Discussion of precise time and frequency measurement
> 	<time-nuts at lists.febo.com>
> Subject: Re: [time-nuts] Misuse of word "decimate" (was Re: Short term
> 	10MHz source)
> Message-ID:<29bb671d-83d4-4375-8f4c-0bad25ecb623 at febo.com>
> Content-Type: text/plain; charset=UTF-8
> 
> And just to clarify the subject matter -- the TICC data output contains 12 decimal places, i.e., 1 ps precision.? The actual resolution is about 55 ps, so the last digit is pure noise, and the penultimate digit should really be either 5 or 0.?
> 
> To eliminate the distraction of the noise, It's under consideration to zero the last decimal place, and*maybe*  to round to 50 ps.? I think the last digit is a no-brainer, but am more hesitant about the rounding.