[time-nuts] WWVB PM Time Questions

[rcbuck at atcelectronics.com]

Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna
out of the box this morning. I have a box of 10 left over from the late
80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH
which will be easier to resonate at 60 kHz. Then I need to build up the
RF amp and run the output through a 60 kHz crystal filter. I have to
order the crystals since I don't have any on hand. It will take a couple
of weeks to get the front end working.

I am in Phoenix so the WWVB signal is of decent quality here even during
the daytime. My 25 year old cheap Casio watch will sync up within 2-3
minutes any time of day or night. It normally syncs at 2 am but I have
done tests to confirm daytime sync works reliably.

Mark, I know virtually nothing about SDR other than it works. I bought a
RTL-SDR.Com module a couple of years ago and played with it a little
bit. But it quit working and I haven't thought about SDR since then. My
Icom 7300 is a SDR and it works very well. I think to attempt to design
a SDR would be well over my head. I anticipate this project taking 2-3
months. If I get it working I will be glad to share everything with the
group.

Lester and Paul, I will test with the Costas loop as it may be the
easiest way to go. To test the Costas loop I am basically going to
duplicate the KD2BD design. I was reluctant about it in the beginning
but more reading seems to indicate it will be fine. My AWG allows me to
set the phase from 0 to 360 degrees independently on each channel so I
can use that for initial testing. That testing can be done prior to
getting the front end working.

Richard, is your software posted somewhere? I assume it allows you to
specify the time and date you want it to send. That would come in handy
for writing the code to extract the timer/date data. I have seen
examples of the Arduino transmitting the old AM signal but don't recall
seeing one that sends the BPSK stream.

I have a GPS time receiver with a 1.2 inch LED display that I built a
couple of years ago. I have it setup so the UART outputs the gprmc NEMA
string in case I want to look at it. I have a couple of spare GPS
modules lying around and several Arduino Uno modules. I have no problem
picking up the GPS satellites using only the patch antenna that is built
into the modules.

Ray,
AB7HE