[Milsurplus] Doubting the Foxhole Radio, conclusions

[KD7JYK DM09]

"Well,,original radio communications used spark gap transmitter,,,and so
called coherent detector receiver,,there were no vacuum tubes.coherent 
detector
must be shaked if it were dot or dash in cw.But it worked,changed the course
of wars."

They used coherers, called such because the materials inside tended to 
cohere in the presence of electromagnetic and electrostatic fields, thus 
closing the circuit.  It was also a vacuum tube.  Tell me about this shaking 
process...

Kurt