Identifying Accutron Transistors

Submitted by kratzjoseph60 on March 10, 2024 - 1:15pm

I have recently gone down the rabbit hole of replacing all the bad components in my horde of accutron coils. I have already sourced the correct capacitors and resistors, but I am having issues finding what transistors were used on the 214 2 wire coils and the various different transistors used on 218 coils. From what I've gathered the 214 3 wire coils have CK722 or AY1117 transistors originally, and that a BC858A will work as a replacement. I have also seen sources stating that a BC847 is a good replacement for the 2 wire coils, but the 847 and the 858A are surface mount components and will ruin the look of the coil in a spaceview. I have yet to see anyone attempt to figure out what the transistors are in the 218 coils. I was wondering if anyone knows what transistors were used in the coils from the factory. Even if the components are obsolete I want to be able to try and find a replacement that's in an acceptable package and size. I am also working on making a coil winder to be able to rewind coils. So if I can find the transistor specs I should in theory be able to completely rebuild any accutron coil I want as long as I have the plastic coil form and the metal hardware on the forms.

Posted March 11, 2024 - 5:52pm

I've been retired from electronics for some time now but an NTE semiconductor book might be of some help to you. It has cross references for nearly all transistors and other semiconductors. But the information will be about 20 years old so take that into consideration. Also take into consideration that I know absolutely nothing about Accutrons. I worked on satellite antenna receivers, televisions and radios.