This low noise preamplifier has a gain of 19 dB in the 30 MHz band. The circuit is from the 80s. Transistors are from the era, and equivalents can be used. The circuit consumption is 13 mA.
This crystal or galena radio was found in documentation from the 1990s. The earpiece must be a...
Found in documentation from the 1980s, this circuit makes use of discrete components of the time....
This variable oscillator with power step for alarms was found in an American documentation from...