On Wed, Feb 4, 2026 at 1:55 AM Peter Coghlan via cctalk <[email protected]> wrote:
> I don't think germanium power switching transistors enjoyed a long and > stellar reign. Maybe this acounts for the apparant rarity of this > version of the board? Or maybe their reliability was poor and they > were quickly superceded by the board version with the silicon transistor > as soon as that technology became available? The only germanium horizontal output transistors that I've come across are the AU101, etc, used in the Perdio Portarama portable TVs. They were not very reliable (and a right pain to change in that set, the CRT has to come out first...) I am surprised there's a VT100 using them. Silicon horizontal output transistors were well-known by that point, and a lot more reliable. The VT52 uses a silicon NPN horizontal output transistor. The VT05 seems to have used at least 2 monitor PCBs, one of which uses the 2N3731 horizontal output transistor which is germanium PNP. But the other version uses a silicon NPN transistor. So by the time the VT100 as introduced silicon NPN transistors were established in this application. -tony
