Compactron

12AE10 Compactron tube (a dual pentode), made by GE

Compactrons are electronic vacuum tube units which contain arrangements of diodes, triodes, or pentodes in multiple combination arrays, as well as high or low-voltage and power types.

History

The Compactron is a 12-pin vacuum tube family introduced in 1961 by General Electric in Owensboro, Kentucky ^[1] to compete with transistorized electronics during the solid state transition.^[2] Television sets were a primary application.

Use was prevalent in televisions because transistors were slow to achieve the high power and frequency capabilities needed particularly in color television sets.

Compactron's integrated valve design helped lower power consumption and heat generation (they were to tubes what integrated circuits were to transistors). Compactrons were also used in a few high end Hi-Fi stereos.^[3] No modern tube based Hi-Fi systems are known to use this tube type, as simpler and more readily available tubes have again filled this niche.

Notable features

The evacuation tips of these tube are the narrow points at the top.

A distinguishing feature of most Compactrons is the placement of the evacuation tip on the bottom end, rather than the top end as was customary with "miniature" tubes, and a characteristic 3/4" diameter circle pin pattern.

• Most Compactrons ranged in glass envelope diameter from 1 1/8" to 2 3/4" depending upon the internal configuration. Variations of the Compactron design were made by Sylvania and by some Japanese firms.

Design variations

These types of compactron are known:

• 6AG11 high-mu twin triode
• 6M11 twin triode - pentode
• 12AE10 twin pentode
• 8B10 twin triode - twin diode
• 38HK7 pentode diode
• 6K11 triple triode
• 6LF6 beam power tetrode with anode cap

Technological obsolescence

Integrated circuits (of the analogue and digital type) gradually took over all of the functions that the compactron was designed for. By the mid-1980s this type of tube was functionally obsolete. Compactrons simply don't exist in any TV sets designed after 1986. Other specialist uses of the tube declined in parallel with the television set manufacture. Manufacture of Compactrons ceased in the early 1990s. Finding replacement parts is very difficult if not impossible, as this component was never standardized.

References

1. ^ Electronic Design
2. ^ junkbox
3. ^ junkbox

• Duntemann, Jeff (2008). "Compactron Tubes: A Junkbox Guide". Copperwood Media LLC.. http://www.junkbox.com/electronics/CompactronTubesIndex.shtml. Retrieved 2009-11-03. 

• "Multi-Function Compactrons Promise Two-Tube Radio". Electronic Design. July 20, 1960. p. 74. http://electronicdesign.com/Articles/Index.cfm?AD=1&ArticleID=4554. Retrieved 2009-11-03.