In article <[EMAIL PROTECTED]>,
Serge Bets <[EMAIL PROTECTED]> wrote:

> Thanks for your reply. I'm not sure to have enough background knowledge
> to understand it fully. You mean the filter removing 77.5 kHz carrier to
> keep 1 Hz pulses needs 17 ms to recognise the lower amplitude during the

No.  The filter removing interfering noise and signals above about 
77.55 kHz and below about 77.45kHz.  It is a fundamental consequence
of physically realisable filters that they introduce delays because
the signal cannot start rising before the input signal starts to rise
and cannot rise fast and have a low bandwidth.

Actually, post detection filter that strips the carrier and its
harmonics may have a similar bandwidth, so may also contribute to
the delay, but it is not the most important filter in the receiver.

> There is something strange: These pulses that should be in theory 100 ms
> (or 200 ms), when seen by "radioclk -t" are always shorter, around
> 92.9 ms (or 190 ms). What could explain that?

The logic slicing level isn't exactly 50% of the peak to peak range.

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