Things like the RTL-SDR can be any kind of radio you like on almost any frequency you like ... faced when trying to connect a Sennheiser wireless microphone to some receivers.

If you’re using the mic for a video conference or TV appearance, a pair of earphones may look more discrete than a pair of over-the-ear headphones. The Sennheiser Profile has a wide frequency ...

For the first time, it is possible to see what is happening on your own transmission frequency ... in Sennheiser’s history, such as the introduction of the first wireless microphone system?