UK Homebrew VHF Matchbox Bugs

There is a lot of interesting tech in these little boxes:  

-- The way they are powered (hearing aid batteries). 

-- The way they are modulated.  

-- The way they use a weather radio to receive the signal.  

-- The very simple on/off switches.  

It is all very cool.  

Thanks to Chuck WB9KZY for sending this video to us.