i had the DIY transistor radio with earpiece
I had "built" it myself, so I was allowed to take it to boarding school and listen to it in the dorm.
Our school allowed us to rig a 150ft copper wire so we could build crystal radios. Just good teachers.
As an aside, I became an engineer because my Physics master was a rampant Communist. Let me explain: He worked for Shell and got sacked for Communist agitation so he became a teacher, and he taught Physics the way he preached communism

He even looked like Lenin
