U/D Ratio Calculator

About the U/D Tool

The U/D Tool is for use with the FCC's translator interference process outlined in §74.1203(a) and §74.1204(f). The tool uses various calculations to determine the service contour of a listener in respect to a 'desired' station as well as determining the interfering contour to an 'undesired' station. This tool should be used by an incumbent station to determine if an interference complaint brought on by a listener claiming interference from a new FM translator application or authorization could be actionable under the rules. It does this by calculating the 'undesired to desired' (U/D) ratio of both stations at the listener's location. The U/D calculation is only one of a few steps necessary to qualify a listener complaint.

You will need the Application ID numbers for both the desired and undesired stations. You can find those application ID numbers at fccdata.org.

Listener Information

Desired Station

Use fccdata.org to get application IDs

(This is your station)

Enter the application ID of the desired station:

Undesired Station Information

(This is the new translator)

Enter the application ID of the undesired station: