Tony Pan wrote:
>
> Thank you everyone for the information. I now have an idea what comprise a
> radio clock receiver.
>
> I may at first attempt to design the whole circuit without using a
> commercial receiver IC.
>
> Basically I need to design a radio receiver circuit that is tuned to 60KHz
> signals. I also need a ferrite antenna.

It's probably cheaper for you to buy Radio Shaft 'Radio Clocks' and strip
out what you need. The OSI units (rebranded) have the RF section in
the antenna and already provide raw data out. There are a couple of
web sites with articles on how to use them, complete with PIC code.

> Can you point me to some online resources about designing a radio receiver
> circuit? Also where to look for a ferrite antenna?

Yeah, it's called a 'search engine'. You can filter the results just
as well as I can.

> > However the world has moved to using GPS to globally
> > distribute accurate time. It is just FARRRRR more reliable.
>
> Is it cheaper?

What's your time worth? What accuracy do you need? A GPS disciplined
VCXO is a LOT cheaper than a Rubidium clock.
How reliable does your 'time set' have to be? Can you freewheel
with a RTC chip for hours or days or months? These factors all
affect how cheap your solution can become.

If I were doing it I'd probably use a temperature compensated xtal osc
and live with the few seconds a month of drift it would have.
The time could be reset whenever the data was retrieved, and
the firmware could learn what compensation was needed to stay
'on time'. It all depends on what accuracy and resolution you need.


R

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