bd40bc7c7a "Travelling Wave Tube Amplifiers". Cole (1985). Retrieved 2 July 2008. p.328. There are a number of RF amplifier tubes that operate in a similar fashion to the TWT, known collectively as velocity-modulated tubes. ^ Zimmerman, Robert (Fall 2000). I recently redesigned my site, and many pages have been moved around. Contents 1 Description 1.1 Basic TWT 1.2 Comparison 1.3 Coupled-cavity TWT 2 Traveling-wave-tube amplifier 3 Invention, development and early use 4 Uses 5 See also 6 References 7 Further reading 8 External links . ^ Dennis Roddy (2006).
Sorry, I can't find that file. San Francisco Press. The best known example is the klystron. Retrieved 2008-07-08. These function as narrowband power amplifiers. By controlling the accelerating voltage, the speed of the electrons flowing down the tube is set to be similar to the speed of the RF signal running down the helix. Helical waveguides have very nonlinear dispersion and thus are only narrowband (but wider than klystron). The main difference between most power supplies and those for vacuum tubes is that efficient vacuum tubes have depressed collectors to recycle kinetic energy of the electrons, so the secondary winding of the power supply needs up to 6 taps of which the helix voltage needs precise regulation. S.