Thanks for the info on the extra columns - I'll try it.

The "Talk Around" setting (my bad calling it TalkAbout) is on page 37 of the TH9000 manual.    It's a field in the channel memory section (as is the voice compander and Reverse TX/RX settings).  

From the manual:

By Talk Around function, you can directly communicate with other radios in your group in case the repeater is not activated or when you are out of range. The transceiver will transmit by RX frequency with its CTCSS/DCS signalling.   

The bad grammar is directly from the manual. The options are ON and OFF.   It appears to be a feature to set the radio in simplex mode using the RX freq, while continuing to use the TX Signalling coding.  

There is also a "Reverse TX/RX" option (per channel) that reverse the TX/RX frequencies and Signalling.