The Simplest FT8 Transceiver You’ll Ever Build

Probably the most interesting aspects of radio amateurs in 2021 are in the field of digital modes. The use of the unlimited possibilities of software-defined radio stations has freed digital radio communication from what can only be done with analog electronics, and as a result it is a rare field in which radio amateurs can still keep up with the technology curve. One of these newer digital modes is the FT8, created by the fruitful [Joe Taylor K1JT].

And that’s for this mode [Charles Hill] has created an easy to build transceiver. His brain is Teeny 3.6, while the host is a Si4735 receiver chip and transmitter is a Si5351 programmable clock chip, control power amplifier Mini-Circuits GVA84 with suitable filter. The interface is via a touch screen. It relies on existing work that applies a patch on the go to the Si4735 receiver chip for SSB reception and another FT8 software project.

The charm of this transceiver is that it can be assembled almost entirely from modules. Some radio enthusiasts may complain that home radios should use only the most basic components gathered from the first principles, but the obvious answer to this should be that anything that makes it easier to design a radio should be welcomed. If the output power of 100 mW seems a bit low, it is worth remembering that the FT8 is a weak signal mode and under the right propagation conditions the world should be able to hear it despite the scarce output.

We introduced a lot of radios using the Si47XX series, which can really turn into very neat receivers.