[GreenKeys] Different Type Of TU

[Jeffrey D Angus]

On 5/22/2016 8:45 PM, JC White wrote:
> A couple of months ago I came across an article for constructing a TU
> that uses no tone filters at all.  The Dec 1991 issue of ELEKTOR, page
> 18 - 20, has an FSK decoder based on a pair of one-shots. Basically,
> they are set to react to the period of an incoming tone, so actual shift
> is not very important.  Neither are the actual tones, as long as the
> periods of the one-shots are adjusted (somewhat).  Having tossed
> together the circuit I am rather surprised how well it works.
It's an interesting idea, one that's been around for quite a while.
<http://zpostbox.ru/frequency_comparator_circuit.html>
This was what was used for a speed control in the 1971 RSGB handbook,
and a variation of which I used with the Lorenz motor speed control
project.



-- 
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

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