The transistor used in this circuit is uncommon today. AC124 or equivalent such as AC188K and 2N2431 can be used. The circuit is from the 80's and makes use of transformers.
Found in a documentation from the 90s, this circuit limits and amplifies a voice signal in the 800...
This circuit is from an Argentine publication from the 1970s but can still be assembled with...
This simple LDO, or low voltage drop regulator was found in an Electronic Design from the 90s. The...