HOW DOES IT WORK
Every fruitful hunt starts from this first most important step! Try to gain as much information as you can: Frequency, Bandwidth, Mode and so forth. Even the smallest detail could be decisive!
Inspect the unknown signal with many useful tools: compare the waterfall, listen to an audio sample to discover similarities or use the advanced filtering functions to reduce possible erroneous matches.
When only a few signal candidates remain in the top list, try to cross every information you have in combination with the most detailed description that is readily available on sigidwiki.com...now should be easy to understand what you are looking for.