Measurement Sets

Features & Benefits

• Many Capabilities in One Instrument
• Digital Waveform Monitor
• Digital Vectorscope
• Picture Display
• Group Delay and Frequency Response
• Noise Measurement Set
• Automatic Measurement Set
• Measure Mode Provides Graphic Display of Measurements
• ICPM
• K Factor
• Differential Gain and Phase
• Chrominance-to-Luminance Delay
• Noise Spectrum
• Group Delay with Sin x/x
• Color Bars
• Relative to Reference on Most Measurements
• Configurable for All Standard Test Signals
• Award-winning User Interface
• Extremely Fast Update Rate
• Parallel and Serial Printer Ports
• Three Input Channels
• Channel Difference Modes
• External VGA Display Port
• Fully Documented Remote Control Operation
• Hardcopy for Analysis and Documentation
• S-Video Capable

Applications

• Research and Development
• Quality Assurance and Signal Compliance Testing
• Automated Functional Test
• Unattended Monitoring of Video Signals from Studios, STL's, Earth Stations, and Transmitters
• Baseband Network Monitoring

NTSC Video Measurements

Recognized with a technical Emmy award, Tektronix' world-class core competencies have enabled it to design and deliver the most comprehensive video measurement solutions in the industry.

Recognized as the de facto industry standard that keeps pace with evolving customer needs, the VM700T is a total solution for your baseband video and audio monitoring and measurement needs. Features such as an extremely fast and fully automatic measurement mode as well as full manual operation provides the first-time user, as well as the seasoned professional, an unequaled value for their test and measurement investment.

Automatic Video Measurement Set

The VM700T Auto mode makes standard video transmitter measurements quickly and automatically, including those specified in RS-250C/EIA-250C, NTC-7, and RS170A. Both vertical interval and full field measurements can be made and compared with user-defined limits. A dual limit verification system is employed to generate a caution or alarm message when either limit is violated. Reports can be generated and printed automatically at operator-scheduled times or triggered from a conditional event.

Graphic Displays of Measurements

Main measure mode display of available measurements.

Measure mode DGDP special position acquisition feature.

Measure mode provides virtual real-time graphic displays of measurement results automatically. Vertical interval or full field measurements including noise spectrum, group delay, K-Factor, differential gain, and differential phase are presented as clever, easy-to-understand interactive digital displays. Such displays are indispensable when extremely fast measurement update rates (up to 30 times a second) are required to provide instant feedback of critical adjustments and analysis of signal variations. User-definable limits are visually integrated into each graphic display and can be used to trigger a measurement report or a user-definable macro function. Such a function can, for example, dial out through a modem to report measurement results or control a signal router. A relative to reference mode allows normalizing to a signal source or eliminate signal path errors from the desired measurement. Up to 2 video references can be stored in NVRAM. Additionally, after downloading to a PC through the VM700T FTP driver, the video reference can be uploaded to another VM700T for reuse. A running averaging mode can be used to reduce the effect of noise. When additional measurement data is required, a user can custom configure measurement parameters and report format.

A powerful Test Signal search capability quickly and automatically locates and identifies valid test signals required for a selected measurement, eliminating the annoying and time-consuming task of manually locating test signals.

Digital Waveform Monitor/Vectorscope

The VM700T Waveform mode application provides real-time graphics displays of the video signal allowing many additional measurements to be made manually. Easy-to-use measurement cursors are available to measure time, frequency, and amplitude parameters of a video signal. These cursors allow a very quick and precise location of the 10%, 50%, and 90% points on any transition. Cursor mode also employs an automatic calculation in the wave shape in the center of the display. The parameters calculated are sine peak-to-peak amplitude, frequency, and offset from blanking level. This is very useful for frequency response measurements with the Multiburst signal.

The waveform display can be expanded around any point both vertically and horizontally. Since the data is digitized, the display remains bright and easy to read at all expansion factors. The scales automatically expand with the waveform, so all units are correct as displayed. A channel difference mode (A-B, A-C, B-A, B-C, C-A, and C-B) is also provided. A screen memory selection enables Envelope mode, which is useful for looking at teletext, Jitter, or other changes over time.

In Vector mode, the VM700T becomes a digital vectorscope with an electronic graticule. A "Color Bar Search" feature makes it easy to quickly display a line containing a color bar test signal.

Vector mode provides the normal vectorscope display. The vectors may be rotated or expanded, with the rotation angle and gain values displayed numerically on the screen.

Vertical interval test signals can be seen very clearly for additional analysis of the signal. These can be printed as support documentation for automatic measurement results.

A unique "Find Color Bars" feature searches all video for Color Bars and displays the vectors if found. The vectors can be referenced to either the selected channel's burst or the burst of one of the other two channels or continuous subcarrier. The phase difference between the selected channel and the reference is always displayed.

Select Line in both Waveform and Vector modes can be used to quickly specify any line for display or automatic measurement if it is the proper signal.

Picture Mode

Picture Mode display. (Video courtesy of KOIN-TV, Portland, Oregon)

Even a single horizontal synchronization pulse can be displayed at a high intensity.

The signal source can be quickly verified using the picture display. Additionally, a "bright-up" line select mode allows a user to select any video line for use in Measure mode or for viewing in Waveform or Vector mode.

User-programmable Functions

Function mode is an extremely powerful feature that allows a user to store a sequence of user operations as a macro function for later "playback."

For example, a set of measurements (complete with hardcopy commands) to be made on a transmitter demodulator video output, could be stored as a function labeled "DEMOD." The function "playback" could then be initiated manually, remotely, or completely automatically as a user-specified timed event. Function files can be stored as a text file on a PC for editing, copying, or uploading to another VM700T. Other function capabilities include controlling of external serial devices such as video/audio routers, switchers, signal generators, telephone modems, and many other devices which support RS-232 communications.

Hardcopy

All information on the screen may be printed in high-resolution graphics on printers supporting PostScript, Hewlett-Packard LaserJet, DeskJet and ThinkJet, or 24-Pin Epson graphics through the Centronics-compatible parallel port or standard RS-232C interface.

Automatic measurement results in text format can be printed on most ASCII printers using the parallel or serial ports.

Remote Operation

The VM700T has a powerful and fully documented remote control language. The VM700T can thus be operated from a remote terminal using RS-232C to monitor unattended transmission systems. In addition, all files can be uploaded to a main computer and downloaded to other VM700Ts. Two different protocols are supported: FTP (File Transfer Protocol) and TELNET. The user can also select a "no protocol" mode of the RS-232C interface when dealing with low baud rates. However, file transfers can only take place with FTP.

Characteristics

The performance requirements cited in this section are valid only within the following environmental limits:

• Temperature range of 0 to 50 °C, with a minimum warm-up time of 20 minutes. The following tables list each measurement and its performance requirement
• The range specifies the extremes between which a measurement can be made
• All measurement accuracies specified are valid only with nominal input signals of 1 V_p-p (±6 dB) with an unweighted signal-to-noise ratio of at least 60 dB on the incoming signal and a termination accuracy of ±0.025% (Tektronix PN 011-0102-xx or equivalent)

Measure Mode*^{1, 2}

*¹ All accuracies for measurements with averaging capabilities assume the default average of 32.

*² All accuracies for measurements with relative to reference mode assume an average of 256 was used to create the reference.

Bar line time measurement.

Bar Line Time

Bounce

Burst Frequency*³

*³ Requires a reference signal.

Chrominance-to-Luminance gain and delay measurement.

Chrominance-to-Luminance Gain and Delay

Chrominance Frequency Response

Chrominance Noise

Chrominance nonlinearity measurement.

Chrominance Nonlinearity*⁴

*⁴ Accuracies for chrominance nonlinearity amplitude and phase measurements assume an average of 256.

Color bar measurement.

Color Bar

SMPTE Color Bars Nominal Values

Differential gain and phase measurement.

Differential Gain and Phase

Frequency response and group delay measurement using Sin x/x.

Frequency Response and Group Delay

Horizontal Blanking

Horizontal timing measurement.

Horizontal Timing

Incidental Carrier Phase Modulation

H Jitter.

Jitter

K-Factor measurement.

K-Factor

Level meter measurement.

Level Meter

Line Frequency

Luminance nonlinearity measurement.

Luminance Nonlinearity

Multiburst measurement.

Multiburst*⁵

*⁵ Total Harmonic Distortion on packets must be ≤46 dB.

Noise spectrum measurement.

Noise Spectrum

SCH phase measurement.

SCH Phase

Vertical blanking display.

Vertical blanking serration pulse measurement.

Vertical Blanking

Auto Mode

RS-170A Horizontal Blanking Interval Timing Measurements

RS-170A Vertical Blanking Interval

FCC Horizontal Blanking Interval Timing Measurements

FCC Vertical Blanking Interval Timing Measurements

Amplitude and Phase Measurements

Frequency Response Measurements

Incidental Carrier Phase Modulation

Color Bar Measurements

Out-of-Service Measurements

Waveform Distortion Measurements

VIRS Measurement

Signal-to-Noise Ratio Measurements

Unified Unweighted filter response curve per CCIR Recommendation 567.

Unified Luminance Weighted filter response curve per CCIR Recommendation 567.

NTC 7 Unweighted filter response.

NTC 7 Luminance Weighted filter response.

Measurement Methods - Auto Mode

The following paragraphs describe the measurement methods for each measurement. Each timing measurement method is written for the FCC method. If there is an RS-170A method for that same measurement, and the RS-170A method differs from the FCC method, the RS-170A requirement is enclosed within square brackets in the FCC description.

Horizontal Interval Timing Measurements

These timing measurements are made within the active picture area, averaging the results over 32 lines starting at line 50 and skipping 1 frame plus 5 lines for each successive sample (i.e., average over line 50 of first field, line 56 of second field, line 62 of the third field, etc.).

• Breezeway Width: Measured from the 10% point on the trailing edge of horizontal sync (nominally -4 IRE) to the leading half-amplitude point of the burst envelope.
• Color Burst Width: Measured from the leading half-amplitude point on the burst envelope [leading zero crossing of the first half-cycle of burst that exceeds 50% of burst amplitude] to the trailing half-amplitude point on the burst envelope [trailing zero crossing of the last half-cycle of burst that exceeds 50% of burst amplitude].
• Front Porch Duration: Measured from the 10% point on the trailing edge of setup (+4 IRE nominally) to the 10% [50%] point on the leading edge of sync (nominally -4 [20] IRE).
• Horizontal Blanking Width: Measured between the points on the leading and trailing edges of horizontal blanking that are at an amplitude of 10% [50%] of sync above blanking level (nominally +4 [+20] IRE).
• Horizontal Sync Rise Time and Fall Time: Measured between the 10% and 90% points on the leading and trailing edges of horizontal sync, respectively (nominally -4 IRE and -36 IRE).
• Horizontal Sync Width: Measured between the 10% [50%] points on the leading and trailing edges of horizontal sync (nominally -4 [-20] IRE).
• SCH Phase: Phase at the middle of burst relative to the 50% point on the sync leading edge.
• Sync to Setup: Measured from the 10% [50%] point on the leading edge of sync (nominally -4 [-20] IRE) to the point on the trailing edge of blanking that is equivalent to 10% of sync (nominally +4 IRE).
• Sync-to-Start of Burst: Measured from the 50% point on the leading edge of sync (nominally -20 IRE) to the leading zero crossing of the first half-cycle of burst that exceeds 50% of burst amplitude.
• Sync-to-End of Burst: Measured from the 10% point on the leading edge of horizontal sync (nominally -4 IRE) to the half-amplitude point on the trailing edge of the burst envelope.

Vertical Interval Timing

Equalizing Pulse Width: Measured between the 10% [50%] points on the equalizing pulse (nominally -4 [-20] IRE).

Serration Width: Measured between the 10% [50%] points of serration (nominally -4 [-20] IRE).

Vertical Blanking Width: Measured between the points on setup [active picture] at a level equal to 10% [50%] of sync amplitude (nominally +4 [+20] IRE), where setup [active picture] immediately precedes and follows the vertical blanking interval.

Color Bar Measurements

Color Bar Amplitude Error: Measured as deviation of the peak-to-peak amplitude of each color bar from the nominal value for that color bar expressed as a percent of the nominal value. Six values reported.

Color Bar Phase Error: Measured as deviation of the phase of each color bar from the nominal phase for that color bar, relative to burst phase. Six values reported.

Color Bar Chrominance-Luminance Gain Ratio: Measured as ratio of chrominance level to luminance level of each color bar, relative to the nominal ratio for each color bar. Six values reported.

Color Bar Values

Amplitude and Phase Measurements (FCC or NTC-7 Composite VITS)

VITS ID display.

• Bar Top: Measured as the ratio of the bar top to Zero Carrier amplitude to the blanking (at back porch) to the Zero Carrier amplitude. Result expressed as a percent of Max Carrier.
• Bar Amplitude: Measured from the reference blanking level (at back porch) contained within the test line to the level at the center of the bar.
• Burst Amplitude: VITS not required. Burst amplitude must be at least 10 IRE. Measured as peak-to-peak amplitude of the color burst at burst center.
• Chrominance-Luminance Delay Inequality (Relative Chrominance Time): Measured as the time difference between the luminance component and chrominance component of the modulated 12.5T pulse.
• Chrominance-Luminance Gain Inequality (Relative Chrominance Level): Measured as the peak-to-peak amplitude of the chrominance component of the modulated 12.5T pulse.
• Differential Gain: Measured as the absolute amplitude difference between the smallest and largest staircase chrominance packets. Result expressed as a percent of the largest packet amplitude.
• Differential Phase: Measured as the largest difference in phase between any two staircase chrominance packets.
• Luminance Nonlinear Distortion: Measured as the difference between the largest and smallest step amplitudes of the staircase at the center of each step. Result expressed as a percent of the largest step amplitude difference.
• Relative Burst Gain: Measured as the difference between the peak-to-peak amplitude of burst and the staircase chrominance packet located at blanking. Result expressed as a percent of the packet amplitude.
• Relative Burst Phase: Measured as the difference in phase between the color burst and the staircase packet located at blanking.
• Sync Amplitude: Measured from the tip of the horizontal sync pulse to blanking level.
• Blanking Level: Measured as the ratio of the blanking (at back porch) to Zero Carrier amplitude to the sync tip to Zero Carrier amplitude. Result expressed as a percent of Max Carrier.
• Sync Variation: Measured as the peak-to-peak variation of the horizontal sync pulse amplitude within every third line of a field.
• Blanking Variation: Measured as the peak-to-peak variation of the blanking level within every third line of a field.

Frequency Response Measurements (FCC Multiburst or NTC-7 Combination VITS)

• Multiburst Flag Amplitude: Measured from back porch blanking to the center point of the flag top.
• Multiburst Amplitude: Measured as the peak-to-peak amplitude of each of the multiburst packets. Six results reported.

Waveform Distortion Measurements (FCC or NTC-7 Composite VITS)

• Line Time Distortion: Measured as the peak-to-peak amplitude change of the bar top, excluding the first microsecond and the last microsecond.
• Pulse-to-Bar Ratio: Measured as the peak amplitude of the 2T pulse, expressed as a percent of the bar amplitude.
• Short Time Waveform Distortion: Measured as a weighted function of time, the result is the peak deviation from flatness within 1 ms of the center of a bar transition. ANSI/IEEE Std.-511-1979, Section 4.4, Appendix B.
• Chrominance Nonlinear Gain Distortion: Measured as the peak-to-peak amplitude of the first (nominally 20 IRE) and last (nominally 80 IRE) chrominance packets in the 3-level chrominance signal, referenced to the peak-to-peak amplitude of the middle packet (nominally 40 IRE).
• Chrominance Nonlinear Phase Distortion: Measured as the difference between the largest and the smallest deviation in phase among the 3-level chrominance test signal subcarrier packets.
• Chrominance-to-Luminance Intermodulation: Measured using the 3-level chrominance test signal. Result is the maximum amplitude departure of a filtered part of the luminance pedestal from a part of the pedestal upon which no subcarrier has been superimposed.
• 2T Pulse K-Factor: Measured as the greatest weighted amplitude of a positive-going or negative-going echo-term half-wave which is within 1 μs before the 2T pulse leading edge half-amplitude point or within 1 μs after the 2T pulse trailing edge half-amplitude point. Result expressed as a K-Factor which is the ratio of the weighted amplitude of the echo-term half-wave to the sampled amplitude of the 2T pulse.

VIRS Setup (Reference Black)

• VIRS Chrominance Reference Amplitude: Measured from the blanking level included in the test signal to setup level.
• VIRS Chrominance Phase Relative to Burst: Measured as the amplitude of the VIRS chrominance packet, expressed as a percent of burst (or percent of bar if no burst).
• VIRS Luminance Reference: Measured as the difference between the VIRS chrominance packet phase and color burst phase.

Signal-to-Noise Ratio Measurements

• Measured from the blanking level included in the test signal to luminance reference level (nominally 50 IRE).
• Unweighted SNR: Measured as the ratio of bar amplitude to the unweighted RMS amplitude of the noise on a quiet line.
• Luminance Weighted SNR: Measured as the ratio of bar amplitude to the luminance-weighted RMS amplitude of the noise on a quiet line.
• Periodic SNR: Measured as the ratio of bar amplitude to the peak-to-peak value of the periodic noise.

Out-of-Service Measurements

• Long Time Distortion: Measured as the peak overshoot and settling time in a flat field test signal switched from 10% to 90% APL in less than 10 μs.
• Field Time Distortion: Measured as the peak-to-peak amplitude change of the 100 IRE field squarewave top. The first and last 250 μs are excluded. Expressed as a percent of the field squarewave amplitude.

Power Requirements

Mains Voltage Range - 87 VAC to 132 VAC or 174 VAC to 250 VAC.

Mains Frequency - 47 Hz to 63 Hz.

Power Consumption - 250 W.

Environmental

Operating Temperature Range - 0 °C to 50 °C ambient.

Safety - UL3111-1, CSA1010.1, EN61010-1, IEC61010-1.

Physical Characteristics

Ordering Information

VM700T Opt. 01

NTSC Video Measurement Set.

Includes: Instruction manual, 75 Ω terminators (3) 011-0102-xx, power cord.

When ordering, please use the nomenclature given here. The standard instrument is shipped as a rackmount product.

Additional Options

Opt. 11 - PAL Measurements.

Opt. 01/11 - Dual-standard Measurements.

Opt. 20 - Teletext Measurements.

Opt. 21 - Camera Measurements.

Opt. 30 - Component Measurements.

Opt. 40 - Audio Measurement Module.

Opt. 41 - 6-channel Audio Measurement Module.

Opt. 42 - Audio-to-Video Delay Measurement.

Opt. 48 - GPIB Interface.

Opt. 1C - Cabinet Version.

Opt. 1G - Echo/Rounding Measurements.

Opt. 1S - Serial Digital Video Measurements.

VM700T Software Utilities

VMBKUP - VM700T backup utility.

VmtWin - VM700T remote control software.

Optional Accessories

VM7FR1 - Field-installable conversion kit to convert cabinet to rackmount unit.

Service

Opt. C3 - Calibration Service 3 Years.

Opt. C5 - Calibration Service 5 Years.

Opt. D1 - Calibration Data Report.

Opt. D3 - Calibration Data Report 3 Years (with Opt. C3).

Opt. D5 - Calibration Data Report 5 Years (with Opt. C5).

Opt. R3 - Repair Service 3 Years.

Opt. R5 - Repair Service 5 Years.