SoC/SBC Boards for Ham Radio (2)

Figure 1: FLDigi is shown running on the Pi2, decoding a BPSK signal, using Cirrus audio.

The Cirrus adapter worked just fine on the Pi2, as can be seen in figure 1.0. I took the audio first from the “phones” jack of an old amateur radio receiver, and then from the sound card of a second PC running a browser webSDR page. This audio was connected via the “line-in” connector of the Cirrus adapter in the Pi2 box. In both cases the audio was very good, and was adequate to decode signals while using a only a moderate input level. The noise and spur levels were much less than on an i386 PC based machine I had used for FLDigi/ham activities in the past.

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A Second SDR for the Desktop

Figure 1: I liked the “Soft66 Lite” so much I decided I needed another for the desktop, in addition to the one purchased for the homemade tablet. For the desktop unit, a separate enclosure was needed.

These tiny little things are addicting! The enclosure was outfitted with a couple switches to do bandswitch duty, since (unlike the homemade tablet) there will be no GPIO to apply for that function. A big, clunky SO-238 connector was attached to the box, to accept the PL-259 plug from the antenna coax. And of course, holes were made for the audio and power connectors.

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A Shortwave Receiver for the “Homemade” Tablet

Figure 1: The “soft66 Lite” SDR (software defined radio) board. It’s a fun thing to build in a spare three hours, and even more fun to operate!

Recently I’d integrated a “homemade”  tablet into the station, for things like receiving weather faxes and BPSK31 transmissions.  I’d been using external receivers to do that, but mentioned that I really wanted to put a “shortwave” receiver board inside the tablet, for an all-in-one effect…

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