20 julio, 2026
This is the 3rd Edition of the classic Hollow-State Design book by Grayson Evans, an authority on thermatrons (vacuum tubes), their use primarily in amateur radio circuits and equipment. Table of Contents: 1. Introduction 2. Why Build with Thermatrons? 3. Inside the Thermatron 4. Numbering Systems, Bases, Bulbs 5. Thermatron Characteristics 6. Keeping the Filaments Lit 7. Power Thermatrons 8. Thermatron Homebrew Techniques 9. Designing with Triodes 10. Designing with Pentodes 11. Designing Thermatron Oscillators 12. Thermatron Mixers 13. Designing Power Amplifiers 14. So Many Thermatrons, So Little Time 15. Get to Know a Thermatron NOTE: All copies sold on ebay will be autographed by me (the author).

