The BITX40 is a low cost, single band (40m), low power, SSB transceiver kit. Now ‘kit’ isn’t really what you might make of the word. It is a fully assembled (and supposedly tested) circuit board, along with a collection of external parts, wires, all house in a plastic box. The ‘kit’ part comes into play when it comes to final assembly and enhancements.
The BITX40 uses an Arduino controlled VFO called the Raduino which includes a 2 line LCD. The Arduino is a programmable microcontroller, which means that you can modify its program to enhance and extend the functions of the BITX40.
My BITX has a few modifications. I added a fix for a pop that occurs when switching between transmit and receive. I also added an audio AGC to even out loud signals next to weaker sounds.
I also customized the Raduino to display my callsign, and modified the tuning step. Here is my BITX40, fairly far along in the construction process.
More detail later on the construction and customizations.