We have prepared a few DIY CPO kits (Around 50, completely sold out ) for our new batch of ASOC aspirants. Here is the schematic diagram of the same, it’s just a twin T oscillator with an LM386 as the audio amplifier.
You should download the assembly instructions from here, before you start assembling it. Also, do find some novel ways to house the kit and battery. See one by Ragav ,VU3VWR in the following picture.
SIARS is a non-profit organisation, promoting amateur radio and is based in Chennai.