Pititico 1 transistor transceiver

You may be interested in this (and other) videos on the Pititico transceiver on DX Explorer. 

As there is no amplification of the audio on RX I imagine it is not very sensitive so probably safer to call stations you can hear. Putting out a call you might squash another station already there that you cannot hear!

DX Explorer YouTube channel

This is a YouTube channel I really like. It is sponsored by PCBway. The videos are of a modest person from Eastern Europe exploring various aspects of the radio hobby. The one here is just an example.

Simple regen RX

This site is really, really good. He is so modest and talks through his journey into amateur radio. In this video he is trying to make a simple regen RX better.

DX Explorer video

This site is great. He always tries new things. I like that he is a true experimenter.