Tektronix 7904A Oscilloscope

The Tektronix 7904A is a 500 MHz non-storage oscilloscope mainframe with four plug-in compartments, introduced in 1984 as an enhanced redesign of the 7904 incorporating integrated circuits from the 1 GHz 7104 model. It accepts the full range of 7000-series plug-in units, delivering system flexibility for high-speed pulse and digital circuit characterization, telecommunications, and research applications. The instrument features an 8 cm × 10 cm CRT display with alphanumeric readout of plug-in parameters including deflection factor and sweep rate, plus dual-trace vertical and dual-sweep horizontal capability through electronic switching.

– Technical Specifications

• Bandwidth: Up to 500 MHz (3 dB down)
• Mainframe Architecture: Non-storage, four-bay configuration—two left compartments for vertical deflection, two right for horizontal
• Display: CRT with 8 cm × 10 cm graticule; P31 (green) or P11 (blue) phosphor options
• CRT Readout: Alphanumeric display of encoded parameters from plug-in units
• Y Delay Line: 65 ns
• Maximum Sweep Speed: 5 ns/div
• Signal Path: Completely differential; internal wiring 50 Ω coax
• CRT Deflection Plates: Distributed vertical configuration
• Vertical Deflection Accuracy: 0.1 div or less compression/expansion of center-screen 2 div signal anywhere in graticule
• Vertical Amplitude Accuracy: 1% or less
• Input Impedance: 1 MΩ (varies with plug-in selection)

– Key Features

• Exceptional writing speed derived from 7104 technology
• Flexible triggering via dedicated plug-in units
• Left, Right, and Add vertical display modes
• Free-Run and PULSED readout modes
• Distributed deflection plate topology for fast transient capture

– Typical Applications

• High-speed pulse characterization
• Digital circuit design and verification
• Telecommunications signal analysis
• General-purpose research instrumentation

– Compatibility & Integration

Full compatibility with all 7000-series vertical and horizontal plug-in units enables custom system configurations. The four-bay architecture supports simultaneous operation of independent measurement channels.