[time-nuts] WWV Clock

[Brooke Clarke]

Hi Mike:

Note that the way a clock checks to see of it has received the data correctly 
is to compare two adjacent frames and check to see that they differ by one minute.

If the clock was smart it would start to listen a few minutes prior to midnight 
and would recognize that there was going to be a DST change at midnight.

If the clock started at what it thought was midnight, but it was running a 
second slow then it would miss the first frame, but the next minute it would 
get the "new" frame and switch to/from DST.

I think your clock is just not receiving a good enough signal.  The key may be 
you need to mount the clock on a wall that's 90 degrees from where it is now. 
That's the problem I had with an atomic clock, i.e. the loopstick antenna has 
deep nulls and if you point the null at the transmitter . . .  See:
http://www.prc68.com/I/Shadow-Clock.shtml#WT5360U

I like the projection clock in my bedroom.  No glasses, no light needed to tell 
the time.

Have Fun,

Brooke Clarke
http://www.prc68.com

Mike Monett wrote:
>   Replying to  my own post, there are two bits that  indicate daylight
>   saving time  changes.  Here's a paragraph  from  page  27, Lombardi,
>   "NIST Time  and Frequency Services", NIST  Special  Publication 432,
>   2002 Edition:
> 
>   "Daylight saving  time (DST) and standard time  (ST)  information is
>   transmitted at seconds 57 and 58. When ST is in effect, bits  57 and
>   58 are  set to 0. When DST is in effect, bits 57 and 58  are  set to
>   1."
> 
>   "On the day of a change from ST to DST bit 57 changes from 0 to 1 at
>   0000 UTC, and bit 58 changes from 0 to 1 exactly 24 hours  later. On
>   the day  of a change from DST back to ST bit 57 changes from 1  to 0
>   at 0000 UTC, and bit 58 changes from 1 to 0 exactly 24 hours later."
> 
>     <http://tf.nist.gov/timefreq/general/pdf/1383.pdf>
> 
>   So it  seems the HTAWI receives the bits correctly, but it  does not
>   act on them until both are the same.
> 
>   Some relevant articles are available:
> 
>   NIST Special Publication 432, 2002 Edition
>   NIST Special Publication 250-67
>   WWVB RCC Recommended Practices 2009
> 
>     <http://tf.nist.gov/stations/hflibrary.htm>
> 
>   Regards,
> 
>   Mike Monett
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>