The Dynaco ST-70 is one of the most popular tube amplifiers ever. First released in 1959, it's still sought after by hi-fi enthusiasts today.

A traveling wave tube amplifier operating above 300 GHz based on folded waveguide (FWG) slow-wave structure is presented in this paper. The design and test results of key components are presented, ...

We present the experimental demonstration of a traveling-wave tube (TWT) power amplifier operating in the W-band (75-110 GHz) frequency range. The device is based on a serpentine waveguide (SWG) ...