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 Loewe 3NF (1926) -- the first integrated circuit?
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 Return to top of page · Post #: 1 · Written at 7:21:51 PM on 8 October 2018.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6678

From the wiki:

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

Produced by the German Loewe-Audion GmbH as early as 1926, the device consisted of three triode 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 receiver were the tuning coil, the tuning capacitor and the loudspeaker. The device was produced not to enter the integrated circuit era several decades early, but to evade German taxes levied on a per valve holder basis. As the Loewe set had only one valve holder, 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 (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 tetrodes plus passive components) and the WG38 (two pentodes, a triode and the passive components).

https://www.radiomuseum.org/tubes/tube_3nf.html

===

Some videos:

Russian explanation with English over-dubbing: https://www.youtube.com/watch?v=1E8StV497sQ

Testing a 3NF: https://www.youtube.com/watch?v=WguMWfYKBCI

Loewe receiver: https://www.youtube.com/watch?v=jEXZMkKhuUc


 
 Return to top of page · Post #: 2 · Written at 10:05:54 AM on 10 October 2018.
Simplex's Gravatar
 Location: Bathurst, NSW
 Member since 7 August 2008
 Member #: 336
 Postcount: 391

Read about the 3NF some where else and certainly there was a lot of innovative things tried in those early days.

Even in the days they were made must have been a costly item to buy.


 
 Return to top of page · Post #: 3 · Written at 11:23:07 AM on 11 October 2018.
NewVista's avatar
 Location: Silver City WI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 977

This is amazing for the mid 1920s!

in the video:
The Russian demonstrates radio while holding lit cigarette ( cigs only $1.50 a pack there!)


 
 Return to top of page · Post #: 4 · Written at 4:19:20 PM on 11 October 2018.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2363

"Grandpa, what's a cigarette?"


 
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