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. 

Discover (or rediscover) the fun and magic of building electronic circuits with thermatrons (vacuum tubes).  This book has everything you need to know about the art and science of vacuum tube design and construction.  It pulls together, in one easy to read book, thermatron types and characteristics, thermatron homebrew techniques, and how to design audio and RF triode and pentode circuits.  The book is written primarily for radio amateurs (or audio equipment builders) that already understands basic electronics but have forgotten or never had the pleasure of working with hollow-state devices.

The 3nd Edition has nearly 100 pages of new material and revisions including new chapters on thermatron mixers, power tubes, and power amplifier design.  It is 333, 8.5 x 11” pages, packed with hundreds of photos, schematics, diagrams, charts, and how to examples.  The author, Grayson Evans, KJ7UM has been licensed since 1962, grew up on thermatrons, spent 40 years in the electronics industry, and is bored to death with solid-state!

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).