Tri-tet oscillator (original) (raw)

A tri-tet oscillator is a crystal-controlled vacuum tube electronic oscillator circuit. It is a type of (ECO), which uses a tetrode or pentode tube. The tri-tet was introduced by James J. Lamb in the June 1933 issue of QST magazine. In an ECO, the screen grid acts as a plate for the triode oscillator. Some of the electrons pass through the screen grid to the plate, causing a current to flow in the load. This effectively isolates the oscillator portion from the load, so that loading does not affect the operating frequency. The C2/L2 tank circuit is tuned to the desired harmonic.