Panasonic VP-7721A Manual

automatic ranging mode; therefore, the appropriate range is selectedand the S/N ratio is indicated. The meter ranges of 3 V (10 dB) or10 V (20 dB) and -90 dB will be selected. The meter range LEDassociated with 3 V or 10 V indicates the range of the INPUT LEVELmeter (7) indicating the S (signal) component and the LED of -90 dBindicates the range of the S/N meter (7^) during S/N measurement.--- NOTE --“-1-*The S/N ratio is indicated in dB. The ranges below 0 dBare used for S/N measurement ignoring minus signs (tenranges from 0 dB to 90 dB). The S/N meter uses only thedB scale in green (—20 to +1 dB), and the plus and minussigns should be inverted for reading.Example: Range display —90 dB i\ S/N = 96 dBMeter reading -6 dB J35) The S/N ratio is calculated as the ratio of the S (signal) componentto N (noise) component. The meter (7) indicates the result. Pres¬sing the S/N key causes the analyzer to operate as shown in Fig. 4-3S/N□PressedS component isautomaticallyswitched toN component. N component,Ampli¬tude.This value is comparedto the stored S com¬ponent, S/N is calculatedand the result is indicat¬ed by the meter (7TAbout1.5sec.This value is stored, and indicatedby the INPUT LEVEL meter (7) evenafter switching from S to N.-Time7 Fig. 4-3 S/N measurement■MOCMoI00e:4-16