[amsat-bb] Re: DTMF on HF?

[Gus]

Unfortunately, in some cases the differences are very close.  "C" and 
"3" have pairs with a differential only 1 Hz apart.

Perhaps some heuristic approach which examines several consecutive 
tone-pairs, looking for a single offset that would make them all valid?

On 01/10/2014 06:31 PM, Joe Leikhim wrote:
> Since DTMF has two tones for each number, it would seem possible that
> you could have some DSP detect the difference frequency of each pair and
> then either adjust its decoders or QSY the receiver's VCO to get a lock.
> There are a ton of small development boards like Raspberry PI that have
> hardware that might be able to do this.
>
> Has anybody got the AMSAT-bb daily digest to work through their e-mail
> provider other than Gmail?
>

-- 
Gus 8P6SM
The Easternmost Isle