| 摘要 |
PURPOSE:To enable increase in the frequency to be analyzed and displayed with a simple constitution and a low cost, by enabling simultaneous switching of tuning frequencies of a plurality of band-pass filters over to respective different ones with a change-switch. CONSTITUTION:In a spectrum indicator which displays a plurality of frequency component through a plurality of band-pass filters, change-over switches 1-6 are provided which switch tuning frequencies of a plurality of band-pass filters simultaneously over to respective different tuning frequencies. In other words, capacitors C1-C6 for determining the tuning frequencies connected to operational amplifiers 7, 8 and 9 composing the band-pass filters are so arranged as to be switched by the group of two types with change-over switches 1-6 interlocking them. Thus, change-over switches are provided to switch tuning frequencies of the plurality of band-pass filters simultaneously to respective different ones thereby enabling increase in the number of frequencies to be analyzed and displayed with a simple construction and at a low cost. |
