Turret board
Encyclopedia
Turret boards were an early attempt at making electronic circuit
s that were relatively rugged, producible, and serviceable in the days before printed circuit board
s (PCBs). As this method was somewhat more expensive than conventional "point-to-point" wiring techniques, it was generally found in the more expensive components, such as professional, commercial, and military audio and test equipment. This is similar to cordwood construction.
Turret boards consist of a thin (generally 1/8 inch) piece of non-conductive material drilled in pattern to match the electronic layout of a set of components. Each hole drilled will have a turret positioned in it. Electronic components are suspended between these turrets and soldered to them to create a complete circuit layout.
Most of the military electronics used in WWII
made use of this construction method, and Altec
professional gear of similar vintage has the same construction. However, the underside of some turret boards, such as a consumer Zenith 1A10 console radio, circa 1940, consists of an array of electronics components that are simply suspended, rather than tethered or soldered down, and thus could move unexpectedly. Such construction methods tended to keep the neighborhood radio repairman in work. In general, however, the use of turrets and turret boards dramatically improved reliability and serviceability.
Turret boards additionally allowed some degree of "engineered" construction. That is, an engineer could design a turret board with listed component interconnects such that it could be assembled by someone skilled in component recognition and soldering. A schematic was unnecessary for assembly.
Until reliable high-temperature printed circuit boards were developed, turret board construction was considered the best available technology. Currently, the use of turret boards is limited to hand-wired vacuum tube
electronics (be it commercial or hobby), often as an attempt to replicate a classic design or design approach. Popular "DIY" (Do-It-Yourself) components utilizing this approach include reproduction vintage guitar amplifiers and certain professional studio components from the 1960s, such as the classic and still widely used Teletronix LA2A tube compressor. In general, however, due to the expense and time-consuming nature of turret board construction methods, experimental or test-stage electronics projects generally make use of one of the many types of perfboard
available, while final circuits—both hobby and commercial—utilize printed circuit boards.
Electronic circuit
An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow...
s that were relatively rugged, producible, and serviceable in the days before printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s (PCBs). As this method was somewhat more expensive than conventional "point-to-point" wiring techniques, it was generally found in the more expensive components, such as professional, commercial, and military audio and test equipment. This is similar to cordwood construction.
Turret boards consist of a thin (generally 1/8 inch) piece of non-conductive material drilled in pattern to match the electronic layout of a set of components. Each hole drilled will have a turret positioned in it. Electronic components are suspended between these turrets and soldered to them to create a complete circuit layout.
Most of the military electronics used in WWII
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
made use of this construction method, and Altec
Altec Lansing
Altec Lansing is a line of professional, home, automotive, computer, and multimedia audio products first developed in 1936. They were used in many studios as monitor speakers...
professional gear of similar vintage has the same construction. However, the underside of some turret boards, such as a consumer Zenith 1A10 console radio, circa 1940, consists of an array of electronics components that are simply suspended, rather than tethered or soldered down, and thus could move unexpectedly. Such construction methods tended to keep the neighborhood radio repairman in work. In general, however, the use of turrets and turret boards dramatically improved reliability and serviceability.
Turret boards additionally allowed some degree of "engineered" construction. That is, an engineer could design a turret board with listed component interconnects such that it could be assembled by someone skilled in component recognition and soldering. A schematic was unnecessary for assembly.
Until reliable high-temperature printed circuit boards were developed, turret board construction was considered the best available technology. Currently, the use of turret boards is limited to hand-wired vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
electronics (be it commercial or hobby), often as an attempt to replicate a classic design or design approach. Popular "DIY" (Do-It-Yourself) components utilizing this approach include reproduction vintage guitar amplifiers and certain professional studio components from the 1960s, such as the classic and still widely used Teletronix LA2A tube compressor. In general, however, due to the expense and time-consuming nature of turret board construction methods, experimental or test-stage electronics projects generally make use of one of the many types of perfboard
Perfboard
Perfboard is a material for prototyping electronic circuits. It is a thin, rigid sheet with holes pre-drilled at standard intervals across a grid, usually a square grid of 2.54 mm spacing. These holes are ringed by round or square copper pads...
available, while final circuits—both hobby and commercial—utilize printed circuit boards.