Capacities...
The scanner's manual doesn't go into any detail at all, and I'm not at liberty to give too much, but here are some rough sample values for what the PRO-107 can "hold". All numbers are per-gigabyte (1,000,000,000 bytes) of available SD Card space, and all values are "exclusive" of all others (e.g. if you have the max number of conventional channels, there's no room left for trunked systems, etc.)...
* Conventional channels, each in two playlists: 8 million
* Trunked systems, minimum 20 talkgroups per system: 6 thousand
* Trunked systems, every possible talkgroup (~65,000) in every system: 151
* Minimum number of total talkgroups (@ one per system, 6000 systems): 6 thousand
* Maximum number of total talkgroups (@ ~65,000 per system, 151 systems): 9.8 million
* Entire 15NOV2009 USA RadioReference database imported (including digital): twice
In the above, each trunked system has up to 50 sites (though there's no practical limit). All talkgroup numbers presume all systems are "Motorola Type-II" - the system type that a) uses the most space per talkgroup, b) potentially wastes the most space per talkgroup, and c) has the largest number of possible talkgroups. The minimum and maximum numbers of talkgroups are absolutes; actual values depend on system types as well as how talkgroups are distributed among systems and within systems. No "RadioIDs" are included in the above.
In more general terms:
* Conventional channels: limited only by SD Card space and max FAT32 file size
* Trunked systems: limited only by SD Card space
* Sites per system: limited only by SD Card space
* Frequencies per site: fixed at 32 (yes, I know it's too many)
* Talkgroups per system: limited only by SD Card space, up to maximum for system type