Radio Theory and design

 

Using an op amp  for a simple radio. Single 9 volt supply. An example of how to "split" the supply ans create a reference for the ...

This little circuit is a start point for an active antenna. I labeled some tie pints to help with the hookup. The gain is good. Look at the ...

A question about this circuit started me looking at it. It uses a 9 volt supply but why? The audio amp and Vcap tuning require 9 volts. The ...

  The four transistors produce a Vcap to tune the oscillator. The sim is stepping the 10k pot from 1k to 10k in 1k steps. The 100p cap (C2) ...

 Back to the project. I will be going with the 3 volt supply. My earbud is rated at 1ma. This amp look good. The input is 500uv for 1 ma out...

 I'm putting this here so it does not get misplaced.