CALLIOPE is one of the main filters in JAGUAR. CALLIOPE (as any JAGUAR filter) can be used in the BASE, STEEP and STUDIO filter modes. These modes have different attenuation curves at the filter edges.
The CALLIOPE filter can leak audio +/- 96 kHz away from a frequency of a nearby powerhouse. It is never a problem if you listen to the frequencies of your local continent but can be an issue when listening to trans-oceanic signals, and the frequency you are listening to is matching that 96-kHz difference from any nearby broadcaster.
You can use the "F" key to rotate the filters until you see CALLIOPE displayed on AUDIOBAR.
You can also select CALLIOPE directly from that button (click/scroll until you get CALLIOPE), or you can select it from TOPMENU > FILTERS. Also, the FILTER APPLET can be used: click the FILTER button until you see CALLIOPE displayed.
The CALLIOPE filter characteristics (BW, OFFSET, BASE/STEEP/STUDIO mode) can be adjusted via the FILTER APPLET, AUDIOBAR or AUDIO WINDOW. More information on how to tune these can be found in the APPLET / AUDIOBAR / AUDIO WINDOW help sections.
The selected filter mode (BASE/STEEP/STUDIO) is also displayed over the FILTER APPLET: BASE = no fishnet, STEEP = red fishnet, STUDIO = white fishnet.
The STEEP and STUDIO modes will clear the audio frequency ranges outside the selected filter bandwidth. The effect can be seen in the AUDIO WINDOW and heard in the headphones. Sometimes you will make a clear improvement in the audio by means of either of these modes.