wwvb receiver chip needed

[Albert]

I need a Temic U4224B chip, which is used for reception of DCF and
WWVB time signals at vlf.

Are these available without going to Europe?

Thanks,

A

 

[Joerg]

Hello Albert,

I need a Temic U4224B chip, which is used for reception of DCF and
WWVB time signals at vlf.

Are these available without going to Europe?

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

Regards, Joerg

 

[Mark Zenier]

Hello Albert,


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

In any case, Temic was bought out by Atmel.

Mark Zenier [email protected] Washington State resident

 

[Joerg]

Hello Mark,

In any case, Temic was bought out by Atmel.

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

Regards, Joerg

 

[Tim Shoppa]

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:

http://www.leapsecond.com/pages/sony-wwvb/

Tim.

 

[Joerg]

Hello Tim,

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.

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

 

[Albert]

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

 

[Joerg]

Hello Albert,

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.

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

 

[Tim Shoppa]

two crystals. These alone can cost more

than a whole clock.

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.

 

[Albert]

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

 

[Joel Kolstad]

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.

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

 

[Michael A. Terrell]

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...)

---Joel Kolstad

Take a look at Jim Thompson's early design. He's an IC designer who
hangs out on the sci.electronics.* newsgroups.
http://www.analog-innovations.com/SED/WWVB-Schematic+Data.pdf

 

[Joel Kolstad]

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

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

 

[Jim Thompson]

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

 

[Michael A. Terrell]

Particularly considering it was done BC (Before CAD

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

...Jim Thompson

A "Before and after"?

 

[Joerg]

Hello Jim,

Particularly considering it was done BC (Before CAD

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

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

 

[Joerg]

Hello Tim,

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.

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.

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?

Strange. Maybe another resonance mode?

Regards, Joerg

 

[Michael A. Terrell]

Strange. Maybe another resonance mode?

Regards, Joerg

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

 

[Joerg]

Hello Michael,

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

Maybe but most WWVB receivers are more crude. They aren't concerned
about shape factors and stuff, all they want is enough selectivity to
make sure the things sync at night even if in California or Arizona. So
there is usally one crystal as a filter, or two in series for the better
ones.

Regards, Joerg

 

[Rich Grise]

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?

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

Cheers!
Rich