Channel investigations of a helical-scan digital video recorder at normal and trick-mode playback

Based on a modified 8 mm mechanism using Metal-Evaporated tapes and special heads which provide a track width of 10 mu m, we have realised a recording channel with a raw bit rate of 72 Mb/s suitable for recording of compressed HDTV signals. The recorder employs a 24-25 code with embedded tracking tones for channel coding and Reed-Solomon product codes for error-correction coding. For full utilization of the available error-correction coding in trick modes, studies have been made on the signal behaviour in such situations. Through the use of a PC-controlled error-statistics measurement system we are able to evaluate the real-time performance of the recording channel.<>