FEATURES The TEKTRONIX 7844/R7844 is a solid-state, wide bandwidth, dual-beam oscilloscope. The instrument accepts TEKTRONIX 7000-Series plug-in units to form a complete measurement system. The flexibility of the plug-in feature and variety of plug-in units available allow the system to be used for many different measurement applications. The 7844/R7844 provides separate vertical and horizontal deflection systems in addition to FOCUS, INTENSITY, and BEAMFINDER functions for each beam. The plug-in unit in either vertical compartment can be selected to provide vertical deflection for either beam. The plug-in units in either horizontal compartment may be selected to provide horizontal deflection for either beam. The 7844/R7844 features regulated dc power supplies to ensure that the performance is not affected by variations in line voltage and frequency, or by changes in load due to varying power requirements of the plug-in units. The 7844/R7844 operates from a 115 V or 230 V {50 Hz to 400 Hz) nominal line source. Other features include a dual-gun full-overlap crt with a graticule area of 8 x 10 centimeters. The instrument also provides a crt display of alphanumeric information encoded by the plug-in units. The READOUT display indicates plug-in unit status such as deflection factor, sweep rate, and other plug-in dependent parameters. The Option 21 instrument is basically the same as the standard 7844/R7844 except that the vertical deflection system is dedicated. The amplifier unit in the LEFT VERT compartment controls the vertical deflection of beam 1 and the amplifier unit in the RIGHT VERT compartment controls the vertical deflection of beam 2. The VERTICAL MODE switch and VERT SEP control have been deleted.