Electrical and electronic apparatus, namely, power supplies, potentiometers, fine adjustment locks, analogue control input, transformers and adjustable transformers; network apparatus, namely, standard rail power unites, power supply plug-in cards; network insertion boards for assembly frames; electronic loads; current sinks; adjustable apparatus for supplying a load, namely, resistance decades, inductance decades and capacitance decades; network analyzers; meters for measuring harmonic oscil...