This is the third Ca. 1934 TNT CW Transmitter in the NEWSM collection. Please see the George Grammer Designed TNT (Tuned-Not-Tuned) Transmitter #1 for design details and reference material.
This TNT Transmitter was made by an unknown home builder. As with TNT #1, it is built according to the plans in the December 1929 issue of QST magazine with updates published in the 1934 ARRL Handbook. It has a Cunningham CX-310 tube (7.5V Filament, 425Vmax @ 18 mA) that has the same characteristics as the RCA UX-210 tube used in TNT #1. This TNT came with a large selection of plate and grid coils.
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The transmitter came with a filament (7.5V) and plate (?V) power supply that we have not investigated yet. It has two tube sockets and one Radiotron UX-280 (5.0V Filament, 400Vmax @ 110 mA) Full-Wave Rectifier tube installed.
References for TNT (Tuned plate Not Tuned grid) transmitter
- Building A 1929 Style TNT Transmitter, well illustrated build by VE7SL, Steve McDonald
- Planning and Building Transmitters, form 1934 ARRL Handbook (also referenced in above text)
- The Planning and Building of an Award-Winning TNT, by Nigel Wiegand, W0VLZ. Includes links to
videos of the TNT transmitter that he built. - The Saga of the TNT Transmitter, 1981 story of how W2SN addressed numerous hurdles while
building his TNT transmitter - The Single Control Transmitter, by George Grammer, Dec., 1929 QST (also referenced in above text)
- The TNT – A 1929 Single Control Transmitter, by Steve McDonald, reference on the Antique Wireless
Association Project Files page. - Vintage CW Transmitters, by Gary Poland. Illustrates and describes several reproductions of classic
1920’s transmitters, including the TNT built by Gary Poland, W8PU