The Tek 1780R Series Video Measurement Set offers features for precise evaluation of studio and transmission performance. This multi-function instrument is a wide bandwidth, multi-input, waveform/vector/SCH measurement package. The advantages of separate waveform and vector instruments are provided in a single rack width, 5.25 in. or 133.4 mm high package. In addition, specific measurements take advantage of the 1780R Series' shared waveform monitor and vectorscope internal processing. Separate, optimized waveform and vector display CRTs allow simultaneous monitoring of several video parameters.
Characteristics / Specifications
Vertical Range, Full Scale -
Fixed: 1.0 V ±.007 V.
Variable: Approximately 0.67 to 2.00 V.
Vertical Magnification - Fixed, Variable, X5.
Maximum Input Signal -
AC Coupled: 2.0 Vp-p, 10% -90% AP.
DC Coupled: ±1.5 V (DC + peak AD).
Return Loss -
Inputs A, B, B2 or B3: < 40 dB DC to 5 MHz.
Aux Video in, Aux Video out, Pix Mon out
< 34 dB DC to 5 MHz.
External Sync Input: < 46 dB DC to 5 MHz.
Waveform Monitor Vertical System
Frequency Response (Flat X1) -
50 kHz - 5 MHz:
Input CH A, B, B2 and B3: 1%.
5 MHz - 10 MHz:
Input CH A: 1%.
CH B1, B2 and B3: 2%.
10 MHz - 15 MHz:
Input CH A, B1, B2 and B3: +2%, -5%.
15 MHz 20 MHz:
Input CH A, B1, B2 and B3: +2%, -15%.
Voltage Cursor -
Resolution: 1 mV.
Accuracy: 1.00 V ±0.2%.
Resolution: 1 mV at 1.00 V.
DC Restorer -
Mains Hum Attenuation:
Slow Clamp: < 0.9 dB.
Fast Clamp: > 26 dB.
Lum/Chroma Gain Ratio - 1:1 ±1%.
Vertical Overscan -
1 Vp-p Modulated Sin2 Composite Signal, X5 Gain: < 7 mV variation in baseline of chroma when positioned anywhere between sync tip and 100% white.
DC Channel Matching -
Typically Within: 10 mV.
Common Mode Rejection (A-B1) -
60 Hz: A-B > 46 dB.
15 kHz: A-B > 46 dB.
1 MHz: A-B > 40 dB.
FSC: A-B > 34 dB.
Luminance: < 3 dB down at 1 MHz, > 40 dB down at FSC.
Low Pass: > 14 dB down at 500 kHz.
Chrominance: Typically ±1% of flat at FSC, 3 dB points ±.75 MHz FSC, within ±.15 MHz.
Diff'd Steps: < 40 dB at FSC.
Linear Waveform Distortion -
Pulse Overshoot and Ringing: < 1% of applied pulse amplitude.
25 µs Bar Tilt: < 1% of applied square wave amplitude.
2T Sin2 Pulse to Bar Ratio: 1:1 ±1%.
Non-linear Waveform Distortion -
Aux Video and Pix Mon out:
Differential Gain: < 0.25%, 10-90% APL. Differential Phase: < 0.25°, 10-90% APL.
Input Resistance - Nominally 1.0 mega ohms.
Input RC Product - Nominally 20 µs (20 pF).
Gain Full Scale - 0.1 V, 1.0 V ±3%.
Frequency Response - 25 Hz to 10 MHz: ±3%.
Probe Calibrator - 1.0 V ±0.5%.
Waveform Monitor Horizontal Deflection System
Sweep Rates and Timing Accuracy -
1H (5 µs/div): ±2%. 2H (10 µs/div): ±2%.
3H (15 µs/div): ±2%.
1F displays 1 full field including field rate sync. 2F displays 2 full fields, first field selectable even or odd. 3F displays 3 full fields, first field selectable even or odd.
Sweep Linearity -
1H, 2H or 3H: ±1%.
1F, 2F or 3F: ±0.5 div.
Slow Sweep: ±5% full screen over sweep length.
Magnified Sweep Accuracy -
X5 (1 µs/div): ±1%. X10 (0.5 µs/div): ±2%.
X20 (0.25 µs/div): ±3%. X25 (0.2 µs/div): ±3%.
X50 (0.1 µs/div): ±3%. X100 (50 ns/div): ±5%.
Magnified Sweep Linearity - ±1 minor division (< 2%).
Variable Sweep Range - < ±20%.
Slow Sweep Duration - 4 - 12 sec.
Timing Cursors - Accuracy: 5 ns any delay within one line.
Line Select -
Range: Full field, waveform and vector monitors may select different lines.
Field Selection: 1 of 4 for NTSC (1780R) or 1 of 8 for PAL (1781R), even, odd or all fields.
Staircase Input: 10 Vp-p for 9 division wide display ±1.4 major divisions.
Staircase Operating Signal: DC signal levels plus peak AC, not to exceed -12 V to +12 V.
Maximum AC Signal: 12 Vp-p.
Field or Line Rate: Front panel selectable.
External Horizontal Input - 0 to +5 V. 5 V is nominally a 10 div H sweep.
Waveform Monitor Differential Gain and Differential Phase Display
Differential Gain (DG) -
Deflection Factor: 5% DG deflects the trace 50 IRE (1780R) or 500 mV (1781R) ±5%.
Residual DG (10-90% APL): < 0.2% last 90% of track.
Calibrated DG (CRT Readout) -
Accuracy: 0.1% ±10% of reading.
Differential Phase (D) -
Deflection Factor: 5° D deflects the trace 50
IRE (1780R) or 500 mV (1781R) ±5%.
Residual D: (10-90% APL) < 0.1° last 90% of trace.
Calibrated D (CRT readout):
Resolution: 0.05°. Accuracy: Burst lock ±0.1° over any 10° increment; ±0.2° over full 360° range; Ext ref ±0.1° over full 360° range.
Digital Recursive Vertical Filter -
Displayed Error Signal White Noise Reduction: Approx. 15 dB.
Cross Luminance Rejection: Approx. 30 dB.
Unit Sample Response: Settles to within 1 dB in 50 samples.
Chrominance Bandwidth: 500 kHz ±100 kHz baseband.
Sync Input - Internal:
Reference Sync Separator: 0.2 to 2.0 Vp-p composite video. Internal Sync Separator: 0.5 to 2.0 Vp-p composite video.
Black Burst: 286 mV (1780R), 300 mV (1781R) sync and burst amplitude, +6/-14dB Composite Sync: 0.2 to 8.0 Vp-p. SCH Modes: 286 mV (1780R), 300 mV (1781R) sync burst ±3 dB.
Direct Sync -
Horizontal Frequency Range: 15.734 kHz ±100 Hz.
AFC Sync -
Horizontal Frequency Range: 15.734 kHz ±200 Hz.
Lock-in Time: < 1 second.
Slow Sweep Triggering -
Signal APL change from < 10% to 90%.
Sensitivity: 0.4 to 2.0 Vp-p composite video with APL change.
Rate: > 0.2 Hz.
Remote Sync -
Amplitude: 2.0 to 5.0 V squarewave or 4.0 V composite sync.
Vectorscope Vector Display
Digital Phase Shifter Phase Accuracy - 0.1°.
Chrominance Bandwidth -
Upper -3 dB Point: Fsc +500 kHz, ±100 kHz.
Lower -3 dB Point: Fsc -500 kHz, ±100 kHz.
Display - Vector Phase Accuracy: ±1.25°.
Quadrature Phasing - ±0.5°.
Subcarrier Regenerator -
Pull-in Range: ±50 Hz of Fsc (1780R), ±10 Hz of Fsc (1781R, typically ±50 Hz).
Phase Shift with Burst Amplitude Change:
Phase Shift with Input Channel Change: < 2°.
Clamp Stability - Better than 0.4 mm.
Variable Gain Range - +14 dB to -6 dB of 75% colorbar preset gain.
Variable Gain Phase Shift - < 1° as gain is varied +3 dB to -6 dB.
Vectorscope XY Display
DC Coupled Differential Inputs Through Rear Panel Connector -
Input Amplitude: 2 to 9 Vp-p, adjustable internally for full scale deflection 0 dBm to +12 dBm for 600 ohms system. Factory set to 0 dBm.
Maximum Input Voltage: ±15 V combined peak signal and DC.
Frequency Response: DC to < 500 kHz.
X and Y Input Phase Matching: < one trace width of separation to 20 kHz.
Vectorscope SCH Phase Display
Absolute: ±5° phase at 25°C.
Relative: Typically ±2°.
Acquisition Time: < 1 second.
Display Range -
Absolute (Internal Reference): ±70°.
Relative (External Reference): 360° Indicates correct color framing.
CRTs and High Voltage Supplies
Waveform Monitor -
Viewing Area: 80 mm x 100 mm.
Accelerating Potential: Nominally 20 kV.
Viewing Area: 80 mm x 100 mm.
Accelerating Potential: Nominally 13.75 kV.