Calibrating the generator

About self-calibration

The generator can calibrate itself. Once calibrated, the generator does not require periodic calibration. There are no physical controls to adjust. All calibration is electronic.

Self-calibrating generators output very accurate analog video swings; more accurate then can be measured with most oscilloscopes. By comparing the output of these products with a chopped precision DC voltage source, swing accuracys better than ±5mv and component matches better than ±3mv have been routinely measured.

Given that the calibration circuit has a swing measurement accuracy of ±5mv, calibration of a nominally 700mV video signal should yield an actual video swing of between 695mV to 705mV. In the worst case, this would represent an error of ±0.7%.

The generator output consists of a buffer amplifier (with near 0-ohm output Z) and a

75-ohm source resistor. The resistor is inserted between a buffer amplifier output and the output terminal of the generator. The calibration circuit measures voltage at the output of the buffer amplifier – not at the output terminal, therefore any errors in the internal source or external load resistors will not be calibrated and will remain.

This could potentially add an additional 1% error to the mix. So a nominally 700mV video signal should yield an actual video swing of 688mV to 712mV at the output terminal into a 1% 75-ohm load. In the worst case, this would represent an error of ±1.7%.

Our current swing spec is ±14mV (or ±2%).

Using the Tektronix VM700T, which has a measurement uncertainty of 0.5% (or ±3.5mV at 700mV), we would expect readings between 684.5mV to 715.5mV video, when the generator output is within 1.7% of 0.7Vp-p (in the absolute worst case). Using a typical oscilloscope, which might have a swing measurement accuracy of ±14mV. In this case, we should expect readings between 674mV to 726mV under the same conditions.

How to calibrate generator

To calibrate the generator:

1.Connect the generator with VGM.

2.Connect a display to the generator, and display any static image.

3.In the VGM connections pane, select the generator, and then choose Tools > CMD Terminal.

4.In the CMD box, enter SCAL.

The generator displays the image you selected in step 2 after the calibration process is completed.

12 Chapter 2 Operating Procedures

802R-PCI specifications

Quantum Data 802R-PCI is a cutting-edge solution designed for testing and validating display technologies, particularly in the realm of video and audio applications. This advanced tool is widely used in industries such as broadcasting, consumer electronics, and digital signage, where high performance and reliability are paramount.

One of the main features of the Quantum Data 802R-PCI is its ability to support a wide range of video formats and resolutions, including high-definition (HD) and ultra-high-definition (UHD) video signals. This flexibility allows users to ensure their devices can handle various video standards, from standard definition (SD) to the latest 4K and 8K formats. The device is equipped with a robust set of input and output options, ensuring compatibility with a diverse array of devices, including HDMI, DisplayPort, and various other video interfaces.

Another significant characteristic of the Quantum Data 802R-PCI is its advanced signal analysis capabilities. It employs state-of-the-art technologies for real-time analysis of video signals, enabling users to detect issues such as signal degradation, timing errors, and format mismatches. The built-in oscilloscopes and waveform monitors provide visual representations of signals, making it easier for engineers to diagnose problems quickly and effectively.

The Quantum Data 802R-PCI also features comprehensive support for audio testing, crucial for applications where high-quality sound is essential. It is capable of testing various audio formats, including PCM, Dolby Digital, and DTS, among others. This ensures that users can validate the audio performance of their devices alongside the video capabilities, making it a complete solution for multimedia testing.

Additionally, its user-friendly interface and intuitive software make operation straightforward, even for those new to video testing technologies. The device is complemented by robust reporting tools, which allow users to generate detailed test reports for quality assurance and compliance purposes.

In summary, the Quantum Data 802R-PCI is an indispensable tool for professionals in the video and audio industries. With its extensive support for multiple formats, advanced analysis capabilities, and user-friendly design, it stands out as a premier choice for testing and validating next-generation multimedia devices.