6SN7 Preamplifier (T1105E)

This preamp circuit has a typical configuration as found in a 1946 publication. Supply voltages are indicated.

Soft Start Regulator (CB15498E)
When establishing the voltage at the input of this regulator, the output voltage rises smoothly until...
High Voltage SCR Variable DC Power Supply (CB13382E)
We found this circuit in a documentation about SCRs from the 70s. The circuit can be implemented with a...
Fiber Optic Link (CB14351E)
The operational ones used in this project are old types from National Semiconductor, since the...