The Model120A dc to 200 kc Oscilloscope is a general purpose oscilloscope employing a 5AQP- mono- accelerator precision type cathode-ray tube. It can be used with either internal or external sweeps which can be either .internally or externally synchronized and it can be obtained in either the cabinet or rack type mounting. Because ·0£ its high sensitiVity and balanced input, the Model 120A may often be used directly with transducers, enabling you to see a direct presentation of phenomena desired without having to resort to preamplifiers. The balanced vertical amplifi.er may also be used as· a differential amplifier amplifying the desired signals and re- jecting extraneous induced signals.