The Tektronix 1720 is an NTSC vectorscope for precision composite video signal monitoring in broadcast, studio, and production environments. It delivers vector phase accuracy within 1.25° and gain accuracy within 2.5% (typical), enabling quantitative analysis of color and signal levels. The instrument features a bright CRT display with parallax-free internal graticules and mesh-type geometry for improved measurement fidelity. Its intuitive control interface and variable graticule illumination support both qualitative assessment and detailed technical evaluation of NTSC signals.
Technical Specifications
• Video Standard: NTSC (System M); PAL version (1721) and dual PAL/NTSC option (1725) available
• Display: Bright CRT with mesh-type geometry; white phosphor option available
• Graticule: Variable scale illumination; parallax-free internal graticules
• Dimensions: 8.5 inches wide × 5.25 inches high
• Weight: 8.5 pounds
• Power: AC source; 12 Vdc via optional field upgrade kit (1700F10)
• Input Impedance: >15 kΩ
• Maximum Input: ±5 V DC + peak AC
• Return Loss: >40 dB (50 kHz to 6 MHz)
• Loop-through Isolation: >70 dB at FSC
• Channel Isolation: >70 dB at FSC
– Key Features
• Vector phase accuracy within 1.25°; gain accuracy within 2.5% (typical)
• Quadrature phasing within 0.5° (typical)
• Subcarrier regeneration with pull-in range of FSC ±50 Hz and pull-in time within 1 second
• Simultaneous dual-channel (A & B) display capability with RGB/YRGB vector modes
• X-Y mode for audio phase and gain measurements
• Differential phase and gain measurement with 2° phase scale and 5% gain scale markings
• Center dot clamping with <0.4 mm spot movement stability
• SCH (Subcarrier to Horizontal) phase error measurement available (1720SCH-Series)
• Internal or external synchronization; external reference via CW subcarrier regenerator
– Typical Applications
• NTSC composite video signal verification and compliance monitoring
• Color vector analysis in broadcast and studio environments
• Differential phase and gain measurement for video quality assessment
• Audio phase correlation via X-Y display mode
– Compatibility & Integration
Auxiliary mode operation available when coupled with 1730 Series Waveform Monitor for line-selective analysis. Production from 1986 onward.
