Some interesting suggestions for operations. Keep them coming. I'm always looking for fresh ideas and many of these are already under consideration for future implementation.
Regarding the sub audible tone idea - I like the thought but that will only work on the Kenwood D700. The VHF and UHF Ericsson units are not reprogrammable and as such would not send the tone when the crew used them.
Regarding the drive for packet - I suspect that comes from the fact that there are several crossband repeater style satellites available (SO-50, AO-51 and VO-52) and very few easily accessible packet satellites orbiting. PCSAT is only functional in full sun, ANDE and RAFT require significant ground stations and will be deorbiting in a relatively short time.
Ideally, each radio system on ISS will support a unique operation so that nearly everyone would have something to play with. Currently, the Kenwood radio is being used as a prime radio for everything. That means changing it from one mode to the next a lot. The simplest switch is from voice to packet (3 steps). Activation of the crossband repeater is (unfortunately) a 27 step process and therefore is crew intensive. That is a major driver in it's activation.
Once the planned hardware is aboard and installed, having each system dedicated to a specific operation will minimize the need for mode changes and crew interaction. There will be more unattended modes of operation available for longer periods of time. When a crew member wishes to be active, they will have several options to do so but should they not want to be active, they just turn the volume down and the unattended operations will not suffer as they do now.
Kenneth - N5VHO