(Continued from Part 1. This concludes the article.) Some Additional Notes Here are some additional notes on the circuit design and practical use of the Franzi one-tube radio kit: First, it’s noticeable that this is a hybrid radio. It uses a 6J1 valve (tube), equivalent to the EF95 (also known as 6AK5), as a regenerative detector, followed by a transistor (T2) acting as a preamplifier, and then a power amplifier (the well-known LM386) to provide enough audio power to the speaker, It doesn’t include a headphone output, which is a downside, however a simple modification and a high impedance earphone … The post Building a Simple One-Tube Radio Kit – Part 2, by Mike in Alaska appeared first on SurvivalBlog.com.