File:Replacing 2SA798 dual transistor with two TO-92 single transistors ENG.svg
Jump to navigation
Jump to search
Size of this PNG preview of this SVG file: 799 × 292 pixels. Other resolutions: 320 × 117 pixels | 640 × 234 pixels | 1,024 × 374 pixels | 1,280 × 468 pixels | 2,560 × 936 pixels | 930 × 340 pixels.
Original file (SVG file, nominally 930 × 340 pixels, file size: 67 KB)
Captions
Captions
Also applies to the 2sa979
Summary[edit]
| Description |
English: Many vintage Japanese hi-fi components (including the Optonica 2121H) contain the 2SA798 dual transistor with BCECB pinout. After 40-50 years these are likely to fail at random, and should be replaced whenever possible. There is no modern drop-in substitute, so a replacement is usually made of two generic PNP transistors in TO-92 package. There are hundreds of types available; as long as their rated voltage and current exceed 40V and 100mA of the 2SA798, and the beta is high enough, any well-matched pair will do. Matching is easy if you have something like twenty devices from the same factory batch - there will almost always be two or more very closely matched pairs. TO-92 transistors may have either CBE (e.g. BC556) or BCE (e.g. KSC922) pinout, but in either case mating two transistors is as easy as 1-2-3-4. More in the video [1]
Русский: В японской аппаратуре 1970-х (да и позже) годов часто применялась двухтранзисторная сборка 2SA798, на практике - по прошествии сорока лет - нередко выходящая из строя. Никакой замены в аналогичном корпусе с цоколевкой BCECB давно не производится. При восстановлении аппаратуры (да и просто профилактики ради) сборка заменяется на два дискретных транзистора в корпусе ТО-92. В зависимости от цоколевки транзисторов (в центре база либо в центре коллектор) применяются две конфигурации. Подбор пар - при наличии хотя бы двух десятков транзисторов из одной партии - сложности не составляет. Для выравнивания температур два транзистора склеиваются цианакрилом и одеваются в общую термоусадку. |
| Date | |
| Source | Own work |
| Author | Retired electrician |
Licensing[edit]
I, the copyright holder of this work, hereby publish it under the following license:
 
|
This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. |
| The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
|
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 20:39, 21 February 2020 | | 930 × 340 (67 KB) | Retired electrician (talk | contribs) | {{Information |Description={{en|1=Many vintage Japanese hi-fi components (including the Optonica 2121H) contain the 2SA798 dual transistor with BCECB pinout. After 40-50 years these are prone for random failures and should be replaced whenever possible. There is no modern drop-in substitute, so a replacement is usually made of two generic PNP transistors in TO-92 package. There are hundreds of them available; as long as their rated voltage and current exceed 40V and 100mA of the 2SA798, and t... |
You cannot overwrite this file.
File usage on Commons
The following page uses this file:
