To activate the FCC curves routines, click the FCC "Curves Access" check box under the "Study Type" menu item. When you do this, the "FCC Curves" work area becomes visible.
Select a curve value, F(50-50) service or protected signal contour curve, F(50-10) interference signal curve or the newer DTV curve F(50-90).
Input the power and HAAT in the appropriate text boxes.
Make sure you have a channel assigned in CONTOUR's "Channel" text box under "Transmitter parameters" of the main screen. This is how CONTOUR knows which curves to use, i.e. low & high VHF or UHF.
Assuming you want a distance of a given signal, input the desired signal in the "Contour" input box then click the "OK" button. This will cause CONTOUR to deliver the distance to your desired signal contour at your given ERP and HAAT.
If you desire the signal value at a distance, input the desired distance in the "distance" text box. Then, click the "OK" button and the program will report the signal value at the given distance from the transmitter. (Note: this function is not available for the F(50-90) curves.
When you are finished click the "Curves Access" menu, unchecking it to "off" and the FCC Curves routine will be removed from your screen.