[LEAPSECS] DUT1

[Tom Van Baak]

> It is not necessary, at least in the case of WWV and WWVB, to have special

> equipment beyond a short wave radio to decode DUT1. It can be done by

> ear.


In 1975 short-wave radios were common, but today a short-wave
radio qualifies as "special equipment".

Even with a SW radio, when was the last time you listened to the
*subcode* of WWV? These are not the famous 1 second ticks
we're talking about; it's the low 100 Hz audio tone that is hidden
below the ticks. It often takes quality headphones or instrument
grade SW radio to hear this. The subcode doesn't come through
on the cheap plastic handheld SW radios.

As for WWVB, that's a LF transmission (60 kHz) not short-wave
and there's no audio to hear. WWVB receivers are plentiful (in
so-called atomic clocks and watches), but none of them decode
DUT1.


> Timings of sun and star observations can be done with a hand-operated

> stop watch to a precision of 0.1 s, the same precision as DUT1. (Not

> to say there won't be personal errors in excess of 0.1 s, but those errors

> will probably be well under 1 s.)


Can you send me a link describing this procedure. I'm surprised
it can be done with just a stopwatch and no optics.


> I suspect the other reasons to drop DUT1 will be persuasive, but the lack

> of commercial decoders is not a valid reason to drop it.


Define "valid" then. If a government is spending taxpayer money
for a data service that citizens haven't used for decades, then it
seems to me there is some validity for dropping the service. Or,
at least replacing that vintage service with something modern.
You can get DUT1 on the web now with 1000x greater precision
of WWV/WWVB.

/tvb