Hollow-State Design is the complete guide to thermatron (vacuum-tube) design with 333 pages of schematics, tips, and how-to examples. The book has everything you need to know about the art and science of thermatron technology

Discover (or rediscover) the fun and magic of building electronic circuits with thermatrons. The first kit is a thermatron version of the original one transistor Michigan Mighty Mite (MMM), a simple CW QRP 80M (or 40M) crystal controlled transmitter.

We have finally added a “companion” HSD high-voltage power supply. It outputs 190V DC and 6.3V AC. It can be used to power the TMMM CW transmitter or any homebrew thermatron device.

Learn how to design and build thermatron homebrew projects with these educational (and fun) videos from KJ7UM.