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Old Transistors.

This subject falls loosely under the heading of wiring, so please forgive me if you are expecting to discuss kA and kW. There again some equipment may still have old transistors in it.


I have become addicted to renovating old radio cassette recorders. It has become an obsession. I saw a model advertised on fleabay that I used to own and had disposed of. I bought it with a view to renovating it and enjoying past listening pleasure with some old comedy and music cassettes.


The Philips cassette recorder is a model N2205 and just pays and records on compact cassettes. It is an early 70s model. The motor speed control will not adjust correctly and the player plays at odd speeds. Also the sound output vaires and I have to bang the machine to achieve full sound output sometimes.


The circuit boards use tin cased/ canned AC127 and AC128 transistors which I believe suffer from internal whisker growth that can cause shorts internally.


Are there any plastic cased transistors that are equivalent these days please?


Z.


Parents
  • There are plenty of equivalents for these but all metal TO1 etc cans.

    AC127  could use  e.g. AC176  2N2430  OC140?

    AC128 could use 2N2706 

    Specs are pretty basic HFE >50 P 340mW(127) 267mW (128)  VCE 16V !!

    Plenty of Japanese Germanium made too . most start 2SA.... but not all 2SA are germanium IIRC anything up to 2SA 479 is germanium you would need NPN for the 127 and PNP for the 128.  I have some data (too much to post) so if you find something feel free to contact and I may be able to help with data and connections.
Reply
  • There are plenty of equivalents for these but all metal TO1 etc cans.

    AC127  could use  e.g. AC176  2N2430  OC140?

    AC128 could use 2N2706 

    Specs are pretty basic HFE >50 P 340mW(127) 267mW (128)  VCE 16V !!

    Plenty of Japanese Germanium made too . most start 2SA.... but not all 2SA are germanium IIRC anything up to 2SA 479 is germanium you would need NPN for the 127 and PNP for the 128.  I have some data (too much to post) so if you find something feel free to contact and I may be able to help with data and connections.
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No Data