|My assembled 40m Pixie
The Pixie is a very simple HF transceiver. Usual power out is in the 200-1000mW region, depending on band and DC power source. It was first developed some years ago but the basic concept is using a PA transistor as a mixer in a simple direct-conversion receiver. On TX this is used as the TX PA.
Being simple, it has a number of limitations but it certainly works. A major issue can be AM broadcast breakthrough, although my 40m version is perfectly usable. I was very impressed with my little kit that came with all parts including a silk-screened PCB, all sockets and a crystal. It needed low-Z Walkman type headphones, a morse key and battery – that was all. On 40m the sensitivity is pretty good with 0.5uV clearly audible and my RF power out is around 400mW. A lack of both RF and AF RX selectivity is also noticeable.
Kits are available from several sources at prices that are hard to beat. I recently bought a kit for $10 with free airmail from China. It is available for less than half this price I subsequently found out. Unbelievable for a fully functional HF transceiver. Of course, being so simple you may prefer just to build it dead-bug fashion. I bought a kit as I wanted to see how my building skills were.
As a mature design, it has been through several iterations, some improve the basic design, but most do so at the expense of increased complexity. You’d be hard pressed to find a circuit for a complete HF CW transceiver much simpler.