They have 55-65 metal strings (12 to 17 basses and 50 treble strings known as prystrunky) tuned chromatically through 5 octaves, with or without retuning mechanisms.
And by using longer tuning pins, and northumbrian smallpipes-influenced tuning beads, some smallpipe drones can easily be retuned to a pitch one or two tones higher.
The catalytic emission control system was more efficient at reducing emissions than the previous non-catalytic system, which allowed engines to be retuned for improved drivability and fuel economy.
Modern transmitters can do this retuning within 15 seconds. 300 ohm balanced transmission lines are more or less standard for shortwave transmitters and antennas, although other values can be found.