Joe, A -16dB pilot carrier would solve the frequency offset problem. This was a common solution for Marine shore stations in the last century. Art, KC6UQH
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Joe Leikhim Sent: Friday, January 10, 2014 2:31 PM To: amsat-bb@AMSAT.Org Subject: [amsat-bb] Re: DTMF on HF?
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?
-- Joe Leikhim
Leikhim and Associates
Communications Consultants
Oviedo, Florida
JLeikhim@Leikhim.com
407-982-0446
WWW.LEIKHIM.COM
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