[time-nuts] WWVB Measurements

[Chris Albertson]

On Sat, Mar 26, 2011 at 4:31 PM, Lenny Story <lenny at codematic.com> wrote:
> Chris,
> My design isn't really that sophisticated hardware wise. Its an 8051
> variant, and the CMMR-60P which can be obtained from Sparkfun.com.  I do
> wind my own antenna, which is just a quad, made from PVC and a metal
> electrical box.  The circuit sits in the center.  It's done with a 2.5 inch
> square, 4 layer board from pcbexpress.com.
> The software samples the bit signal coming from the CMMR, every 10 ms
> (essentially), and uses a 100 bit array to qualify it using a weighting
> algorithm. The start of the bit train, and with it the sequence of 10ms
> samples, is essentially polled very fast to catch the beginning of the
> second as soon as possible.

So you are looking at the output bit of the CMMR-60 once every 10 ms?
  Then I'm guessing you will not get uS level precision.
The software I'm writing runs under Linux and reads the bit every 1
msBut I was wondering if I should do better and try for uS level
timing

I think your success with receivig WWVB must be the antenna.   Could
you say more about it.
=====
Chris Albertson
Redondo Beach, California