[NUT-devel] Broadcasting nuts [PATCH]

[Måns Rullgård]

Rich Felker <dalias at aerifal.cx> writes:

> On Wed, Feb 06, 2008 at 07:02:11PM +0100, Michael Niedermayer wrote:
>> > A clock this bad would drift by 1/4 an hour per day. I doubt anyone
>> > would buy such a clock...
>> 
>> No, but people buy various embeded devices to watch videos and their clocks
>> are supposed to be cheap. And while i dont think they would be off by
>> 15min/day i doubt you can expect more than 1min/day accuracy from them.
>
> FWIW, this matches the estimates in my other email of 0.1% error.
>
> Also, maybe this is getting OT, but truely "broadcast" (in the sense
> of airwaves being involved) applications have a matched-to-sender
> clock pulse already via the PLL or whatever similar circuits they use
> in the tuner equipment.

There is no correlation between the carrier and the data.  The carrier
has nothing whatsoever to do with sender/receiver synchronisation.

> Incidentally, at least as I understand it, PLL itself works on a
> concept similar to what I described, consisting of local clock
> (oscillator) plus adjustments from the input signal, and operating
> without a separate reference clock source.

The input signal *is* the reference clock.  You are suggesting we
remove the input signal.

-- 
Måns Rullgård
mans at mansr.com