area between two curves calculator program

If you already know the FM station class and the HAAT, use FMpower to compute the effective radiated power (ERP) needed to achieve coverage equivalent to the reference (maximum) facilities for the station class. For noncommercial educational stations (except LPFM), coverage over the community of license is defined by the 60 dBu contour (see Section 73.515).įor the appropriate FM interfering contour, please consult Section 73.509 for noncommercial educational stations (88.1 MHz to 91.9 MHz) or Section 73.215 for commercial FM stations (92.1 MHz to 107.9 MHz). That extended service is not protected from interference caused by other stations.Ĭity coverage for commercial FM stations is defined by the F(50,50) 70 dBu contour, per Section 73.315. In the absence of interference, FM stations can often be heard in locations well beyond the protected service contour. 60 dBu service contour for LPFM stationsįor radio stations, the service contour generally does not define the outer limit of listenable signal.60 dBu for all classes of noncommercial educational stations in the reserved band (88.1 to 91.9 MHz)įor LPFM (low power FM) stations, the 60 dBu service contour is not protected from interference caused by changes made to regular FM stations:.60 dBu (1 mV/m) contour for commercial Class A, C3, C2, C1, and C stations.57 dBu contour for commercial Class B1 stations.54 dBu contour for commercial Class B stations.FM Broadcast Radioį(50,50) protected service contours for FM stations are defined as follows:

The class of an FM station may be retrieved from the FM Query. Printable copies of these propagation curves are available at FM and TV Propagation Curves Graphs.Īntenna Height Above Average Terrain ( HAAT) values for a particular FM or TV station can be obtained from the FM Query or the TV Query, or use the HAAT Calculator. This function uses the FCC's CURVES program to make calculations of the F(50,50) FM and NTSC (analog) TV service curves, the F(50,10) interfering signal curves, and the F(50,90) digital TV service curves. This Javascript calculator uses the FM or TV propagation curves to find the distance to a service or interfering contour, or the corresponding field strength at a given contour distance.

Area between two curves calculator program