The RR Wiki indicates you can (for now) receive `conventional` and Motorola TRS systems.
http://wiki.radioreference.com/index.php/Pro-2050
Navigate over to the Travis County page in the RR Database:
http://www.radioreference.com/apps/db/?ctid=2749
You could program in All Points for Metro Care Ambulance
The other TRS (Trunked Radio Systems) are either not supported for your scanner
or do not have any Publci Safety Agencies.
Any of the conventional frequencies listed below that are `AM`, `FM` and NOT `APOC-25` you should be able to receive.
You could also look at the Federal Page and program the `FM` frequencies.
You can also look at the city of Austin's page:
http://www.radioreference.com/apps/db/?aid=4311
Depending where you are, as a rule of thumb you can expect to receive TRS from about 10-15 miles, but conventional systems and their repeaters can extend to 25-45 miles.
Look at the map and the individual cities and experiment.
You can also use (if the scanner has it) a `search` of frequency ranges and see what you pick up.
HTH, Mike