Usually, if your not receiving a channel at the time you rerun a setup on the AM21, you might lose the channel. But, not always. So if you're pointing your antenna at La Crosse, you might lose channels in your other markets that you already have. By running Raleigh NC, you will get 48.2 RF49 La Crosse, if your antenna is receiving that channel at the time of the setup. But I have no way of knowing what your configuration looks like right now. If you have almost all the channels you desire right now I would leave it that way. One thing to remember. There is a good chance when there is a software upgrade and the DVR reboots, you will lose most of your channels attained with your secondary zips and you will have to redo the process to get them back. One helpful hint on that issue. If you look at the settings and help, system info and go to more system info. It lists a lot of system info. If you scroll down the screen it will have listed a primary zip and a secondary zip. These are the last two zip codes run on an AM21 setup. When the DVR reboots, it will retain all the channels in these two zip codes. So if you have hard to attain channels, just make sure that zip is stored in your DVR and it should retain that channel, even after a reboot. So in essence, make sure you have the zips of your hardest to attain channels stored in your DVR, in case of a reboot.