The system is Harris County Central system. And Houston simulcast system. .South Houston and Mutual A 1-2
Took off the outside antenna put the stock on. Nothing not even The state.
As has been mentioned several times, the biggest drawback for reception in your area is simulcast. If you have not already done so, read the
Simulcast Distortion page in the Wiki for a more complete explanation. Unless you are extremely lucky in your location (which, it seems, is not the case based on your comments), the only thing you can do is try to use a directional antenna to focus reception to only one transmitter site. But doing that limits what you can receive that are carried on different sites. It's not something that can be corrected via programming. In a few isolated cases, you might improve your results by either using attenuation, or by using less of an antenna. Doing that night require using a paperclip for an antenna, or no antenna at all. But, again, that may also affect other agencies that you might also want to monitor.
South Houston is on Site 1-52, Harris County Central Simulcast. You can see a map with the simulcast tower locations here:
The most complete database of radio communications data
www.radioreference.com
As far as Houston Public Safety itself goes, it also has a group of simulcast locations, and it's sites, I believe, only carry P25 Phase II traffic, which your scanner cannot receive. The limited number of Houston Public Safety talkgroups that are P25 Phase I are carried on the Houston General Government Services Simulcast, site 3-005, as was noted above in
post 11. A map of that site's tower location can be seen
here.
Your only really effective way to improve results would be to consider acquiring one of the Unication pagers, or a scanner in Uniden's SDS series.