“Funny” Transistor Radio

If you thought something was unusual about the schematic in our last Project, Crystal Set Radio , just take a look at this schematic.

There's a transistor ... but no Batteries are used! But when you finish making the wiring connection, adjust the Tuning control. Hear anything?

If you managed to hear stations on our last Project (you'll have to use an outdoor antenna to make it work), you'll be able to hear AM stations on this one too.

Now put on your thinking cap: why does the Transistor in this Project think it's a diode? Give up?

It's because a transistor is actually two diodes back-to-hack. One diode is from the emitter to base and the second is from the collector to the base. That's why in our circuits using transistors we have currents from emitter to base and another from collector to base. (And vice-versa ... see Project Meet the Transistor in transistor section.)

Try using both the emitter-base and collector-base "junctions" whit other transistors. How well do the different connections work?








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