Building the 2P3 AM Radio

In an Episode of Ham Nation or Amateur Logic featuring Joe Eisenberg (K0NEB), I saw him recommend a few radios as good beginner projects. The 2P3 radio looked like an entertaining project and something I could probably tackle with one of the kids. Amelia had recently discovered an old “boombox” from my youth and was playing the radio a lot. We decided it might be fun to listen to a radio that she had built.

I ordered the kit from Amazon. The instructions come on a beautiful HUGE poster. It has an enormous schematic of the radio. I had wanted to build the radio by stage and is recommended when home brewing a radio. We started from the power conditioning part of the circuit. Once we had all the parts of the power we went back and installed the audio amplifier and worked our way backward.

I had intended to test the build frequently as we went along. Initially I couldn’t get any of the measurements to come out according to the schematic. I would go back and study the schematic and I was absolutely certain we had put the parts in the right polarity, etc. and continued forward. On the final day of the build I finally figured out why. . .

The way the circuit is designed there are purposefully installed breaks in the circuit. There is an X to mark the spot in the 3 points. basically they don’t allow power from the power rail to the circuit block you just finished. Being confident I had quintuple checked everything I bridged the circuit breaks and turned on the power the tested all the levels on the schematic. It worked! first try!!

The 2P3 is definitely NOT a beginner kit. But it is a great kit to build with someone who knows just a little and the finished product is a really nice radio.