Author Archives: James

Soundmodem update

Posted on 2013-11-04 by James

So I had some initial success with the Raspberry Pi and using soundmodem as a software TNC for APRS packet radio. The success seems to have been short-lived. I am able to decode packets from test wave files that I’ve … Continue reading →

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Raspberry Pi & Soundmodem – It works!!

Posted on 2013-10-31 by James

It is a bout time for an update on my Raspberry Pi APRS project. (Part 01) Many months ago I was working on getting a Raspberry Pi working for APRS work. I was experiencing a ton of issues with getting … Continue reading →

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Interface v0.20 laid-out

Posted on 2013-10-16 by James

Having recently explored the signal integrity issues in the Interface v0.11, I’ve re-tooled the board to use the TY-311P transformers in v0.1 which meant a total redesign of the layout. In the most recent version, I’ve grouped the components in … Continue reading →

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More testing …

Posted on 2013-10-12 by James

I thought that I would do a little more side-by-side comparison between the transformer and the capacitor methods of signal isolation. My test bench consisted of: DG1022 function generator DS2202 oscilloscope Sound Card Interface v0.11 As I found that there … Continue reading →

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