I Bought this unit as it is dual purpose and has a high sensitivity range. I have only used to set up a TV Aerial in the loft. I used the Compass on my smart phone to set the rough direction for the Aerial. Fit the battery in the unit and either a patch cable or the feed cable, if you use the feed cable, you will be sure of the picture quality when the cable is fitted to the TV. You can fine tune the signal by the audio tone alone higher the pitch better the signal. The LED's will show the signal quality that you can expect in operation. Any more than two Led's showing and it will be ok. In Short it is quick and easy to use and gives you high confidence that TV will work when connected.