Grayson Evans KJ7UM joins us to talk about the art and science of building with thermatrons! PERMALINK - https://www.hamradioworkbench.com/podcast/hollow-state-design Our Website - http://www.hamradioworkbench.com/ Follow us on Twitter - https://twitter.com/hamworkbench Contact us - http://hamradioworkbench.com/contact Connect with us on Facebook - https://www.facebook.com/groups/hamradioworkbench/ BrandMeister Talkgroup 31075 - https://hose.brandmeister.network/group/31075/ QSO Today Expo https://www.qsotodayhamexpo.com/   Hollow-State Design 2nd Edition  by Grayson Evans | Apr 24, 2013 (Amazon Link Included above) Testers: Hickok Tube testers Resources Book: Tube Lore - Ludwell Sibley https://www.amazon.com/Tube-Lore-II-Ludwell-Sibley/dp/1532376316 Sprat magazine GQRP Club http://www.gqrp.com/sprat.htm Electric Radio Magazine  https://www.ermag.com Hand Made Vacuum Tubes by Claude Paillard https://www.youtube.com/watch?v=EzyXMEpq4qw Antique radio supply Hammon electronics transformers https://www.hammfg.com/ Tube depot   https://tubedepot.com/ Tube Lore By Ludwell Sibley  https://www.amazon.com/Tube-Lore-II-Ludwell-Sibley/dp/1532376316 Electric Radio Magazine https://www.ermag.com/ SPRAT Magazine of the GQRP club http://www.gqrp.com/sprat.htm