atomic clocks

Loopstick vertical: Pure noise and no signal.

Bottom line is that the loopstick should be mounted horizontally and perpendicular to Ft Collins CO. Vertical mounting does NOT work.

Interesting. I have the Time Machine and the Time Machine with a projection clock. With the loopsticks vertical, neither has yet lost sync

That is... the sync annunciator (or what I interpret to be the sync annunciator) in the display is still visible.

Both show the same time, which is unlikely if either had lost sync.

"Of course" an antenna's orientation should match the signal's. Why the La Crosse only works when it doesn't, and it doesn't seem to matter for the Oregon Scientific products -- I don't know.

I suspect the loss of lock delay is rather long. It would not do to have the sync indicator flashing on and off as the signal fades in and out. Besides, the receiver is only powered on for 5 minutes. If you don't mind tearing it apart, just ground the PON (power on) line, and monitor the output with an oscilloscope. No need to use the sync indicator.

Incidentally, with a 1 baud data rate, an LED attached to the data line should give a tolerable visual indication of signal quality. On the Temic[1] chip, the output is rather high impedance, so something like a CMOS buffer will be needed. I might modify mine into something like that when I have time.

I beg to differ. Reception could be miserable and the sync indicator probably won't show a problem for 24 hours. I think (not sure) that it really means that it hasn't received an update for 24 hrs.

I've seen worse RF design mistakes. I couldn't find a teardown of the WS-811561 or any similar La Crosse radio clock. One possible problem is that it's impossible to test a WWVB clock in China as the signal doesn't go that far. It's possible that they designed and tested it using a simulator, which will not have the cross polarization problem. Just guessing.

[1] Temic was bought by Atmel in 1998:

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Ferrite aerials ALWAYS need to be horizontal with the side of the rod roughly facing the transmitter.

The correct name for clocks like this is radio controlled.

In regions where the signal controls the change to and from summer time the normal time these clocks sync themselves is at the time when changes to and from summer time. 02:00 AM in Europe. Some may also sync at other times of day in addition to 02:00 AM.

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Brian Gregory (in the UK). 
To email me please remove all the letter vee from my email address.

I agree in principal. But the antenna in my La Cross is vertical. And my Oregon Scientific clocks work fine with their antennas vertical.

If you like, I can take a photo of the La Cross's internals, and you can see which way the antenna is oriented.

Since my original post, I've discovered that the La Cross tries to sync at midnight. The unit sits next to a large-screen TV, so this sync is often blocked. Once the TV is shut off, the La Cross will almost immediately try to sync again, regardless of the time.

Sorry. Forty lashes with a WD-40 coated loopstick! Principle, of course.

You still don't believe my crude test of antenna orientation?

This I would like to see, especially since I can't find any photos online. I'll trade you.... I'll build up my WWVB module to include a flashing LED, that should demonstrate the quality of the signal by flashing regularly at 1 second intervals when there's a good signal, and flashing much faster and erratically when there's only noise. [1] If you want, I'll mail something to you so that can convince yourself. Now, here's someone that tried it with a vertically mounted loopstick antenna: Notice the rather erratic flashing light pattern. Hmmm...

What I guess(tm) is happening is that you are either in a good location or have a particularly good loopstick, where the difference in antenna orientation produces signal level changes from perhaps very strong, to not so very strong. Therefore, it works in any orientation. At my location, the signal is not so strong, so the variation changes from usable, to totally gone.

I hot wired my Oregon Scientific to run all the time. It burns the battery a bit more, but I can now see WHEN it will sync by simply killing the power and waiting for the display to update. It takes about 5 minutes with a strong signal. After about 9PM PDST, it will erratically start to sync. After midnight, it's very consistently. I haven't been up early enough to test when it stops.

WWVB loopstick winding and oscilloscope photos:

[1] At the very end of the video, notice that the flashing light pattern changes. That's the 1 minute sync pattern.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Why should I disagree with your results?

The fact is that the La Cross antenna is positioned vertically. There's a sort-of-slot for it, and as shipped, it's hot-glued in place.

No trade is needed. Give me a day or two, and I'll send a photo.

A man with my sense of humor...

That's plausible. Some things are always true -- except then they're not.

has the manuals for the TMC transmitters used by all the WWV services. They were designed for the US Navy.

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