Graphical Symbol in full simplified diode, indirectly heated duodiode, indirectly heated or triode, indirectly heated or duotriode with separated cathodes, indirectly heated, heating filament with central tapping, internal screening of the system tetrode pentode, suppressor grid connected with cathode triode - pentode triode - heptode (according to the circuit, the systems may be drawn left-and-right reversed) 1.10.    From Wordnik.com.  [1. Selected Graphical Symbols of Electrotechnology] Reference

It uses a 12AF6 / BD6 remote-cutoff pentode and a 12AV7 dual triode.    From Wordnik.com.  [MATRIXSYNTH] Reference

But ask them to build a push-pull amplifier using pentode vacuum tubes and adjustable gain control and they wouldn't have clue one.    From Wordnik.com.  [Slashdot: Book Reviews] Reference

In triode mode, of course, the screen grids of the KT88 pentode tubes are tied to the plates, and the tubes operate as indirectly heated triodes.    From Wordnik.com.  [Stereophile RSS Feed] Reference

The highly anticipated Oceanus LT-381 features a newly designed large dual-diaphragm capsule, NOS military grade pentode input, transformer-less triode output, and variable omni, cardioid and figure-8 polar patterns.    From Wordnik.com.  [Harmony Central] Reference

A basic ring-modulation function is also available in the unit -- applying a carrier pitch from an external oscillator to the screen grid of the pentode, this allows making inharmonic sum-and-difference pitch sound effects, with a unique vacuum tube pentode sound.    From Wordnik.com.  [MATRIXSYNTH] Reference

6550C push-pull output tubes with a combination of pentode operation and ARC's "partially cathode-coupled topology.".    From Wordnik.com.  [Stereophile RSS Feed] Reference