This elaborate mixer is from an Electronics Today International from the 80s. Operational amplifiers are common and resistors with no value determine the gain of the amplification steps.
We found this circuit in an American publication from the 90s. The transistors must be provided with...
The critical components of this project from a 1978 publication are the transformers, which can be...
September 2017 - Mouser Electronics already has the AP431S adjustable regulator from Diodes...