Panasonic VP-7721A Manual

NOTES(1) The input signal levels (S components) below 1 Vwill limit the selectable ranges for S/N measure¬ment. Detailed information will be described laterin paragraph 4.8.(2) In principle, the S/N key is pressed once more whenthe frequency or amplitude of the S component (inthis case, the signal output from the oscillator)changes. With a restriction that the S/N measure¬ment is made using the internal oscillator, theanalyzer is designed so that the same operation asthe S/N key is repressed is executed internallyjust after the frequency or amplitude setting keystrokes. In manual ranging mode, however, the S/Nmeter range does not return to 0 dB as described instep 39) .(3) The S component.is stored by charging a capacitor.The stored value gradually decreases with time;however, its accuracy is not affected within threeminutes. Repress the S/N key if the S/N ratiomeasurement prolongs for three minutes or more.(4) As described above, the oscillator does not providethe normal output signal while the S/N key is on.In this state, the frequency or output amplitude isindicated normally in the digital display. Thedisplay merely indicates the value within 1.5seconds immediately after the S/N key is pressed.When the oscillator of the analyzer is to be usedas an audio frequency oscillator only, the LEVEL orDISTN key of the MEASUREMENT keys (eT) must be kepton.The operations in the preceding.description (oscillator frequency,output amplitude, level measurement, distortion measurement, andS/N measurement) are basic to this instrument. These operationsare called "normal operation" because setting of each operation isdone when necessary.4-18