lkml.org 
[lkml]   [1998]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: DCF77 driver available
> are there any fm stations broadcasting time signals?
> how about the teletext time? how accurate is that?

FM stations in many countries use several modulation enhancement techiques
which have additional delay as a side-effect. Unfortunately, it isn't possible
to compensate this delay by just shifting the time information as the delay
is variable and depends on the current signal being broadcasted. This makes
FM radio unusable for high precision timekeeping. Anyway, if +/- one second
dispersion is accurate enough for you, it could be usable since (AFAIK) there
can be time information transmitted in RDS (Radio Data System) packets.

I don't have any details on teletext time, but I'm afraid it suffers
from similar problems and it will have similar (im)precision.

Aside from these problems, it's surely worth a try.

Have a nice fortnight
--
Martin `MJ' Mares <mj@ucw.cz> http://atrey.karlin.mff.cuni.cz/~mj/
Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth
"#define QUESTION ((bb) || !(bb))" -- Shakespeare

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html

\
 
 \ /
  Last update: 2005-03-22 13:44    [W:0.042 / U:0.416 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site