Tektronix Instruction Manual for the 1420 NTSC, 1421 PAL, 1422 PAL-M Vectorscope. Contents include Installation, Operating Instructions (Description, Controls and Connectors, Check-Out Procedure, and Obtaining Display Photographs), Specification (Chrominance Processing, Amplifier, Power Supply, Environmental, as well as Physical Characteristics), Circuit Description, Maintenance and Calibration, an Electrical and Mechanical Parts Lists, Servicing Illustrations, Diagrams, and Manual Change Information. Other points of interesting include an exploded view of the instrument, and schematics re: the Demodulator, Input Processing, Phase Lock and Timing, and Sub Ref Switching.