Building a single stage audio amplifier

I have long wanted to build an audio amp for my regenerative receiver, so designed a simple one-stage affair around a BC547 transistor.

My calculations for the design weren’t as good as I had hoped.

I used what I had in my junk box to build the amp.

All the components in place ready for testing.

I hooked up my Hantek 6022BE oscilloscope and wasn’t impressed withe the output signal; it was cropping off the top of the amplified sine wave.

Input signal is the yellow trace with the green being the amplified signal.

I tried changing the values of the biasing resisters until I finally achieved a better result.

The amplified signal looks much better now.

Now it was time to integrate the amplifier into the receiver and turn on the power.

All ready for the smoke test.

The result was pleasing. It worked. But the sound isn’t exactly room filling. That hopefully will change when I build a second stage just the same as the first and add it to the system.

Another successful project.