Multi-function tubes, combining diodes, triodes, and pentodes in various combinations, were recently announced to reduce size and component counts in entertainment and industrial devices. "Compactrons," from General Electric, Owensboro, Ky., have 12 pins arranged around a 3/4-in. diameter base. Bulbs are 1-1/8 in. diameter and overall height ranges from 1 in. to 2-3/4 in. Presently available in sample quantities are:
- A combined oscillator, converter and i-f amplifier.
- A second detector, audio amplifier, power amplifier, and rectifier.
These two types contain the equivalent of a 12BE6, 12BA6, 12AV6, 50C5, and 35W4, the most popular tube lineup in table radios.
For tv applications, where heat and high voltage isolation problems are common, single rather than multi-element compactrons are available.
- Horizontal oscillator and afc, equivalent to a double triode, 6CG7, and double diode, 6AL5.
- Horizontal damper diode, equivalent to a 6AX4GTB.
- Vertical deflection oscillator and amplifier, equivalent to a 6DN7.
- Horizontal deflection amplifier equivalent to a 6DQ6B.
GE engineers see a two-Compactron radio replacing the standard five-tube complement (seven transistors needed for the same performance), a 10-Compactron tv set replacing 15 tubes and three diodes or 24 transistors and 11 diodes, and a seven-Compactron stereo replacing 10 tubes or as many as 26 transistors.
Several metallurgical advances have enabled up to 40 percent reduction in heater power. A multi-function compactron will eventually sell for 20 per cent less than an equivalent number of tubes, according to GE marketing officials. (Electronic Design, July 20, 1960, p. 74)