The 15 MHz portable dual-trace oscilloscope PM 3226 is a compact, lightweight instrument featuring simplicity of operation, for a wide range of use in servicing, research and educational applications. Other features include provision for chopped or alternate display of Y signals, automatic triggering, mains triggering and triggering on the line and frame sync pulses of a television signal. The cathode-ray tube displays a useful screen area calibrated into 8x10 divisions by an external graticule. All circuits are fully transistorized and mounted on printed-circuit boards for ease of maintenance. The straight-forward design and layout combines simple operation with a high degree of reliability.