I'm not experience in making electronics, but I do have a working knowledge of basic circuit laws and such, but we never covered something with transistors such as this BFO metal detector circuit I've been making as a weekend project:
This metal detector is relatively weak and I wanted to improve it a little, but I can't get a grasp on what this circuit in particular is doing. I see 2 oscillators on the left, but they both have transistors in them, and I'm not sure what that does to them. I put them in a simulator and they didn't do anything.
I understand the way this works is supposed to be based on heterodyning. So I'd like to make my reference oscillator, a detector oscillator, then multiply the signal somehow and feed it to my speaker. The speaker will only be able to pick up the lower frequency, difference signal, but that's the one I want. I have no idea how this circuit is doing that.
If this circuit is easy for you to figure out, is there a resource you could direct me to so I can learn how it works as well?