This auction is for a pre-owned Tektronix DC509 Universal Counter Timer plugin module in good condition. The Tektronix DC509 Universal Counter Timer is a high-performance test instrument designed for use within the Tektronix TM 500 or TM 5000 series mainframe system. The device measures frequencies up to 135 MHz.  It features digital LED display indicators for frequency and time measurements. 

Key Features:

• Versatile Functions: Measures frequency, period, ratio, time intervals, width, and totalizes events.
• High Resolution: Features a multi-digit display with auto-ranging units from Hz to GHz and seconds to nanoseconds.
• Dual Channels: Equipped with Channel A and Channel B inputs via front-panel BNC connectors for signal comparison and timing analysis.