atomically correct time

Why not use a GPS receiver and get it the same way the cell sites get time?

--
James T. White

they sell the electronic clock that works on wwb at 10mhz atomic clock at woodcraft stores cheap to build atomic wood clocks,

What are you talking about the power line being wrong? Short term it may be off but long term it's right on. SO- build a clock that uses the power company as a time base and then add a WWVB of GPS receiver to set/verify your time. Galleon has a WWVB receiver, antenna and RS-232 interface to your computer for about $60. See

for the data format from the receiver. If I read it correctly, it's a continuous update, not just once per day.

For a cheapy frequency reference, the color subcarrier from a network TV station should be really close to 3579545 Hz. FCC requires them to be +/- 10 Hz but they're usually much closer than that.

GG

I was wanting to design a clock that updated by both

-the atomic clock radio signal

-cell phone towers

this is because the atomic clock signal sometimes is hard to get so I figured that cellphone towers are more reliable

does anyone have any suggestions

The clocks only update once a day. Realistically since they are crystal controlled even if they can't update for a few days, the average person will never notice. Clocks go out of time because they aren't set exactly right (ie they use the wrong "standard" to set them to, or they are sluggish in pressing the button), and because over a very long time the inaccuracy of the crystal (or the AC line if they use that for the timebase) is off and the accumulated error adds up. But you are hardly likely to notice that a clock is off until it has been long enough since it was set, or in the case of the "atomic clocks" since it last sync'ed up.

Michael

Alternatively (or along with other suggestions), you could use a more precise oscillator that will keep you closer to the actual time when your receiver isn't getting a good enough signal. Check out the DS32kHz, IIRC it's good to within seconds a year.

Even worse than a temporary signal fade, perhaps someday society will break down and all these signals will be gone, then how will anyone know what time it is?

Well, here's a solution. Go to

and scroll down to and click on the fourth picture, the "Most Accurate Wristwatch." No doubt there is an Agilent distributor standing by to take your order.

-----

I think the idea is to get the clock signal and send it to a primairy device and the idea is to have it accurate.

I think it is an aproaching the problem from 2 different angles

Me too ;-)

...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 | |

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Nonsense. It's DTV not HDTV and...

"The change to digital TV is triggered no sooner than the end of 2006, but only when 85% of U.S. homes can receive a digital television picture. Apparently that doesn't mean 'are capable of receiving the signal,' but rather 'have the equipment to view a digital television signal.'

I find it difficult to imagine digital TV market penetration being anywhere close to 85% less than years from today."

I have SEVEN NTSC sets in the house.

I receive signal via Cox Cable.

Unless Cox Cable can provide me with a signal that the new sets can tune WITHOUT A SET-TOP BOX, there is no way I will switch.

But I could probably just cease TV altogether. For instance my office TV is always tuned to Fox News and my back is to it, so radio would suffice.

In the evening we generally just watch a movie from our collection of nearly 300 DVD's.

...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.

Yup. I've even built a little Yagi for channel 56. :-)

Thanks, Rich

[snip]

What do you think those towers on Phoenix South Mountain are for ?:-)

...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.

Why did I read this as 'anatomically correct time'? Like Hubert in Sir Henry at Rawlinson's End:

"In his adolescence, during the long summers of yesterday, he would throw himself naked onto the lawns in a northerly direction parallel to the earthly axis. And with a bluey roman clockface tattoo'd about his private parts, think about Jean Harlow very hard and - from the shadow cast -tell the time with remarkable accuracy. "Look! No hands!" In winter he tried with birthday candles stuck in the end but he was hours slow and the drips hurt. Later, Henry told him to 'put a sock' on the sundial bit."

Paul Burke

Does anyone still receive terrestrial analog TV signals over the air?

I wonder where the subcarrier frequency is generated for the NTSC signals we get out of the coax (which are converted from digital, it looks like). Anyone know? I'm guessing it's in the distribution boxes.

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

What's so interesting about channel 56?

Back in the 70s we had a channel 79 (now channel 57 broadcast frequency) which showed racy movies every Friday night. People bought directional UHF antennas just to get them (they didn't really have much of a broadcast antenna either at the time). Now the signal from the world's tallest free-standing structure is powerful, but the movies are long gone.

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

No, for some reason the same thought crossed my mind.

Michael

It's a local indy that shows nostalgic shows like "Magnum PI" and "Columbo." And there's one that's not so old, "Becker", although I'm seeing rerun reruns already. ;-)

Yeah, now to get free porno, you have to use USENET. ;-P

Cheers! Rich

No, but the first time I saw the subject line, I read, "anatomically correct time". What? They have time with genitals now? ;-P

--
Cheers!
Rich

"Glenn Gundlach" wrote in news: snipped-for-privacy@g44g2000cwa.googlegroups.com:

Note that NTSC standard TV signals are due to go off the air in 2006,IIRC. Due to the forced move to HDTV.

--
Jim Yanik
jyanik
at
kua.net

OK, did anybody _NOT_ read "anatomically correct time"? ;-)

Cheers! Rich