This may be of little help also.
Access via PGM>FUNC>GLOB.
FUNC>SEL provides info.
WIN500 = Max cached tunes under General Tuning in Extended Settings tab.
PSREdit = Max Search Tunes per Scan Cycle under Sweeper/Search Options in Weather/Advanced Configuration tab.
ARC500 = Max Tunes under Global Settings Expert tab
Anyway, the setting value appears to set the number of tunes prior to restart of new group.