a monitor for 433,92 MHz

[This question has been answered, the solution can be found in the comments.]

There are a lot of commercial very low priced remote controls. They mostly use the free 433,92 Mhz in the ISM band. If you decide to use one of these controls, it should be nice to measure first how busy this frequency is in your place. Too much interference from other users will degradete the maximum useable distance for your remote control. My proposel is to develop a small receiver just for this band with a kind of S-meter and some monitor function to get an impression through the day.