A New Random Noise Measuring Instrument for Television Signals
This new method for measuring noise in television signals utilizes the time-gated CRT display for the separation of noise power from the video signal. A small rectangular path of a uniform brightness is sampled from the picture signal and its waveform is displayed with a linear time-base sandwiched in between those of the adjustable reference noises. Since the brightness and the quasi-peak-to-peak amplitude of the two displayed waveforms are compared simultaneously, it is quite easy to match them with reasonable accuracy (about 0.5 dB). The instrument can be used to measure conveniently the noise level of the individual heads of the four-head video-tape recorder as a function of the signal level. It has a provision for the weighting functions against the noise frequency and the signal amplitude. The method is applicable to a very small sample area and this has advantages over the existing methods such as those proposed by Weaver and by Edwardson.
- Print ISSN
- 0361-4573
- Published
- 1967-03
- Content type
- Original Research
- DOI
- 10.5594/J07049