Why not start by building a small audio amplifier that can be powered by a 9V smoke alarm battery? And before you know, it can easily grow into a radio project!
While there is no shortage of circuit designs out there, this one is quite simple to build, uses no special components other than commonly available resistors, capasitores, and transistors. It is low noise and distortion, and can give comfortable listening levels in a small speaker, around 200mW (it is louder than you think!)
Sensitivity with the components shown is about 20mV. Frequency responce begins to fall off at around 20 kHz by capasitor C3.
Here is the circuit diagram below:
Current consumption is less than 5mA from a 9V smoke alarm battery.
There are several ways to go about building it. Check out ''manhattan style''. It makes it easy to get started. This is how I built the circuit:
Yes, it is ugly! And it is quick. But you could make a pretty printed circuit board if you wanted to.
Can you tell me what resistor controls the gain? And are R1 - R2 4.7 K ?
This is a class AB amp, cool! It would make a great headphone amp. Even stereo would only be 10 ma. Yes, the parts are all still widely available. And it's not ugly.
This person sells Manhattan parts and pads that work great. His products are really cool. (The website is right out of 1996) http://www.qrpme.com/?p=product&id=SD2
Manhattan style is awesome, and it impresses people when you show them, which is very important 😊 Thanks for posting this project !!!