Hi,
i have refurbish my old Datron 1061, Analog board, Digital board, power supply. Together with resistance and current board it work excellent . Put in a MAT12 and AD711 after that it worked very good. Problem with sockets, drivers, optical ..
Now it works and very stable.
Today or shall i say the last year refurbish the AC-board. instability and not possible to make a zero calibration. To much noise
Lost Hfe in 2N3905, 2N214C and so on. Many measurement traditionally with diod tester ok , but no gain with curve tracer. Found 6 transistor without/low gain until now from input to TL7. The differential Q21 and Q22 did not match
Now my problem:
I miss information about Teledyne double jfet SU2656M to make it possible to measure with a curve tracer to see if I have to exchange them
I am on the right way. I have spend to may hours but I have retired so ..
I am a bit tired of all this but want to finish with AC-board at the same level as new or better.
Best Regards
S