Switching on a television set in the evenings is a habit for most. Surfing through the channels we may find a telecast we like and go on to watch. While there are no issues on most days, you might occasionally detect a noticeable difference in the audio and video. This could be the audio going faster than the video or lagging behind, or some other minor issue. It might not be a big issue for the end user sitting at home if it happens occasionally, but it definitely is a problem for the television broadcasting company. If this problem persists, their viewership could reduce and affect the revenues adversely. Hence efficient functioning of such systems is their necessity. The biggest user of video and audio analyser equipment is the broadcast industry, with the largest share going to television due to its immense popularity. With the amount of reach and effect this industry has, it needs nothing but the best in equipment.
Here we discuss T&M video and audio analyser equipment for related tests, which includes signal generation and analysis tools for specific technologies, as well as video and audio analyser equipment to test the audio and modulation quality of communication radio for security and military communication.
What to test for
Broadcasting of signals started in analogue form, but in this era we use combinations of analogue and digital modes of communication. Hence the testing parameters should cover both types of signals. The different tests to be performed include content server tests, reception tests, cable-antenna tests, Moving Picture Experts Group (MPEG) coder-decoder (Codec) tests, signal quality and signal condition tests, modem tests, intellectual property (IP) quality tests, etc.
The type of T&M video and audio analyser equipment required to perform these tests include network testers, cable antenna testers, MPEG codec testers, spectrum analysers and power meters. Oscilloscopes, bench-top digital multimeters (DMMs), spectrum analysers, signal sources and audio analysers are generally used for testing at R&D and manufacturing stages.
Profit margin depending on accuracy is high, but so is the competition among the companies producing T&M video and audio analyser equipment. Some big names competing in this sector are Tektronix, Harris, Rohde & Schwarz, Keysight Technologies, Anritsu and Comcon Technologies.
The move to digital in Video and Audio Analyser
“In India, analogue is the widely used form of transmission media. Now we are using orthogonal frequency-division multiplexing (OFDM) for modulation of data. This has led to an increase in the amount of data transmitted in the available bandwidth. Another welcome addition is the move to digital media,” says Vishal Gupta, senior applications specialist (RF/MW) at Keysight. He adds, “Five years back, India’s major mode of transmission was analogue, even in the studios. However, all broadcasters like public or private are moving ahead and introducing the latest standards. Going forward we are all moving towards digital technology. So the latest digital standards allow more video channels as well in the same frequency band and allow for better spectral efficiency. Equipment from five years back were focused on analogue and the latest are on digital.”
The type of equipment ranges from simple signal analysers to complex multiple signal comparators with noise reduction and auto tuning. With this wide a range of equipment, these can be employed at different levels such as high-end equipment for R&D, hand-held equipment for testing and bench-top equipment for basic testing and maintenance.