1940s commercial receiver (T1618E)

This receiver was found in a Radio Electronics from 1949. It is a superheterodyne of the time using 6 tubes.

Code Practice Unijunction Oscillator (CB1430E )
e find this circuit in documentation for radio amateurs of 1974. The unijunction transistor can be...
Announcing Two New Low-Cost, Feature-Rich PIC32 Curiosity Development Boards from Microchip
Rapid Prototyping Boards for 32-bit Applications Include Peripherals, Easy-to-use Interface and...
Sound level meter (CB8225E)
This sound intensity meter was found in a 90s Elektor. The circuit uses an integrated device from...