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.
D+ acts as the "plate" voltage for the tetrode, and is slightly less than B+.
Tri-Tet in popular cultureEdit
- Lamb, James J. “A More Stable Crystal Oscillator of High Harmonic Output.” QST June 1933: 30-32.
- Sterling, George E. 1940. The Radio Manual for Engineers, Inspectors, Students, Operators and Radio Fans. 3rd ed. New York: D. Van Nostrand Company, Inc.
- Shepherd, Jean (October 1980), "Some Guys Make It", 73 Magazine, Peterborough, NH