The Loewe 3NF was an early attempt to combine several functions in one

electronic Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductor * ''Electronics'' (magazine), a defunct American trade journal *Electronic storage, the storage of data using an electronic device *Electronic co ...

device. Produced by the German Loewe-Audion GmbH as early as 1926, the device consisted of three

triode A triode is an electronic amplifying vacuum tube (or ''valve'' in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). Developed from Lee De Forest's 19 ...

valves (tubes) in a single glass envelope together with two fixed capacitors and four fixed resistors required to make a complete radio receiver. The resistors and capacitors had to be sealed in their own glass tubes to prevent them from contaminating the vacuum. The only other parts required to build a

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

receiver were the tuning coil, the tuning capacitor and the loudspeaker. The device was produced not to enter the

integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...

era several decades early, but to evade German taxes levied on a per valveholder basis. As the Loewe set had only one valveholder, it was able to substantially undercut the competition. The resultant radio receiver required a 90 volt HT plus a 4 volt LT (A and B)

battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

(the HT battery provided not only 82.5 volts for the HT, but also two grid bias supplies at −1.5 volts and −7.5 volts). One major disadvantage of the 3NF was that if one filament failed, the whole device was rendered useless. Loewe countered this by offering a filament repair service. Loewe were to also offer the 2NF (two

tetrode A tetrode is a vacuum tube (called ''valve'' in British English) having four active electrodes. The four electrodes in order from the centre are: a thermionic cathode, first and second grids and a plate (called ''anode'' in British English). Th ...

s plus passive components) and the WG38 (two

pentode A pentode is an electronic device having five electrodes. The term most commonly applies to a three-grid amplifying vacuum tube or thermionic valve that was invented by Gilles Holst and Bernhard D.H. Tellegen in 1926. The pentode (called a ''tripl ...

s, a triode and the passive components).

References

Vacuum tubes {{Electronics-stub