wwvb receiver chip needed

Hello Albert,

I am not sure you can get them at all. It might have been obsoleted by now.

Regards, Joerg

In any case, Temic was bought out by Atmel.

Mark Zenier snipped-for-privacy@eskimo.com Washington State resident

The "usual" way of getting a WWVB receiver chip is to buy a cheap WWVB clock and rip out the chip and antenna. Some have external chips/antenna connected via cable already.

A web page showing how to do this with a commonly available Sony WWVB clock is at:

Tim.

Hello Mark,

I believe Atmel called this chip T4224 but when looking for it on their web site it ain't there.

Regards, Joerg

Hello Tim,

Agree. Many like the Sony even contain two crystals. These alone can cost more than a whole clock.

But if it's a matter of pride you can build your own even without any special chips. When I was a kid I built a receiver for DCF in Europe. No crystals, only a few transistors and 741 opamps. It worked great, except that I didn't have a PC or anything to decode the signal with. It was just the detected pulses but these came through nice and clear. With today's opamps you wouldn't even need any transistors to do it. A decent quad can be had for 50c while I paid a whopping $3 for a single re-labeled 741 of rather dubious quality level.

Regards, Joerg

Thanks for this info. Unfortunately, Atmel doesn't make the T4334 now.

But, while searching the site for keywords, I found the ATA5283 and ATA5282 125 khz receiver chips that draw less than 4 microamps while listening. I don't think there is anything inside the chip that limits the frequency of operation though, these should operate at much lower frequencies if an appropriate tuned circuit is attached.

So, I will look at these chips in detail later.

I was attracted to the Temic wwvb/dcf77 receiver chips because they draw 30 microamps...so, a receiver that draws 4 microamps is indeed low power and is very promising.

Regards,

A

Hello Albert,

AFAIK many "atomic clocks" listen to WWVB briefly and then turn off the receiver again. With a very low on/off duty cycle the power consumption of the receiver wouldn't matter so much.

Regards, Joerg

Of the longwave radio frequencies used for time standards, 40kHz (JJY, Japan), 77.5kHz (DCF, Germany) and 60 kHz (WWVB and MSF) crystals are off-the-shelf items in the Digikey catalog at less than a dollar each. I'm guessing their easy availability is because they are commonly used in real receivers.

I've always noted with some curiosity that 77.503kHz, 60.002kHz, and

60.005kHz are off-the-shelf crystals too... used in a direct conversion receiver for DCF/WWV to 3Hz, 2Hz, and 5Hz carrier-detect frequencies maybe?

Tim.

I just noticed the availability of these crystals as I was thinking about using a crystal in the front end to protect the receiver from adjacent frequency qrm. Not sure if this can be done unless one has a chip specially designed to take crystals (such as the Temic U4224B).

Regarding the off frequency crystals.... It might be possible that these are rejects that didn't quite make the 60.000 kilohertx spec?

Thanks,

A

Really...! Hmm... perhaps time to re-visit the "WWVB receiver using op-amps and a small microcontroller" ida? One of the regular contributors to Circuit Cellar Ink tried it a while back (4 years?), but wasn't successful. A successful project would be worth a write-up in some hobbyist magazine (of what's left... Nuts & Volts seems to be about it in the US...)

Anyone know which time service folks in Oz or the Kiwis use?

---Joel Kolstad

Yes, I've seen Jim's design before; it's quite impressive for 1974! For a contemporary design, the idea is that you could get by with far fewer parts (if not fewer transistors -- they're just buried in the ICs!).

---Joel

Particularly considering it was done BC (Before CAD :)

Maybe I should try it again, using off-the-shelf components ??

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Take a look at Jim Thompson's early design. He's an IC designer who hangs out on the sci.electronics.* newsgroups.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

A "Before and after"?

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

Hello Jim,

To be fair you'd have to do it with components that were available at reasonable prices in that era. My 2nd DCF receiver was built with several AF126 germanium transistors. On the first one I cheated by using opamps and somehow that didn't feel right back then.

Except for the fact that one receiver drove a Nixie display I never built one with tubes. Now wouldn't that be something?

Regards, Joerg

Hello Tim,

Yes, but if these crystals are the only thing you'd have to buy right now that would easily become $10 with S&H. Or about half of what an atomic clock is at the discounters and there the price includes a huge display along with the receiver parts.

Strange. Maybe another resonance mode?

Regards, Joerg

Maybe use them with the 60.000 KHz crystals to build a very narrow crystal filter?

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

Yabbut, it'd be a little cumbersome for a wall clock. ;-)

Cheers! Rich

Oh, I'm all for cannibalizing the commercial clocks, what with their pretuned ferrite loops, 60kHz receiver and demodulator, as a cost-and-time-effective method. But if someone did want to roll their own...

I have custom ordered tuning-fork style crystals down to 12kHz, and they were way more than the mass-produced $1 jobbies! I think $30-$50 each in onesies. $1 is really cheap in comparison.

Tim.