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Old 07-01-2007, 09:54 PM
Tommy Tootles
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Default Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency

Jeff Liebermann wrote:

> 40KHz thru 285Khz? Great idea. Just one minor problem. A 1/4 wave
> antenna at about 100Khz frequency is 750 meters long. That's going to
> be a rather large antenna for literally dragging behind you.


Well, your math is correct. However, the so-called "atomic" wrist
watches receive their time signal from WWVB which transmits at 60kHz.

How do they get that 1250 meter long antenna ( 1/4 wave at 60 kHz)
inside that itty bitty wrist watch case? ;-)


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