text: what is the operation of a regenerator  in telecommunications?   regen units were used in old pulse dial systems to clean up the pulse waveform on long distance calls.  the old rotary dials generated a number of pulses (on/off) = to the number dialed.  over a long line, or if routed through trunk exchanges the signal is attenuated so you can't tell on from off.  a regen unit redials the number afresh before the signal is lost.  they were fun to maintain, lots of pins flying everywhere like a gattling gun.  in a modern system this will be a dull box that takes a signal in and cleans it up digitally.