Great 12AT7 regenerative receiver at http://www.w7ekb.com/glowbugs/rx/Regens/regens.htm
Original artical by Green from Electronics Illustrated January 1967.
Has appeared in Popular Communications as well in the last
few years. Good circuit and easy to build. Will also work with 6BQ7 / 6BZ7, which is less expensive than 12AT7. I have built a number of these for myself and Vocational electronics students who wished to practice code for their ham license.