I currently have an HR22 box. I understand if you have 2 coax lines going into it from your dish that you can record 2 programs at the same time. Unfortunately for me, I only have 1 coax right now going into it because I'm in an MDU building that has not upgraded to the newer system that uses SWM's. Thus, I can only record the program I'm watching. If I add a AM21, would I be able to record 2 programs at the same time, such as one my HR22 is watching plus a local OTA coming in through the AM21?