Post subject: Telefunken TFK AD149 Transistor Sub?
Posted: Sep Wed 15, 2021 11:55 pm
Member
Joined: Mar Thu 18, 2021 5:13 pm Posts: 69
Location: Las Vegas, NV
Hello,
I am working on a Telefunken Studio 105 which has a tuner/amp like an Opus. It needs a couple of new output transistors but I will replace all four....anyone know of a good sub or whereabouts of originals?
Thank you...
Last edited by Basil Bond on Sep Fri 17, 2021 5:23 pm, edited 2 times in total.
The AD149 is a very common and cheap Germanium PNP power transistor ... in Europe. I expect it much harder to find in the U.S There are some listed on Ebay US but branded "Sumitomo" (?) could be anything inside the case...
The Motorola 2N1540 should be a suitable sub (or any of the 2N1541/42/43/... with higher max. Vce ratings) and should be available locally.
The Sylvania ECG sub is 121 if that could help.
When substituting Germanium power transistors it is allways recommended to check the output stage bias (idle current) and adjust it if neccessary. These transistors are fragile and have wide characteristics dispersion, usually they were matched at the factory.
