Advertisements I have one MCard installed in my TiVoHD. The self-install was successful with Comcast and took about 30 minutes. I am getting a second TiVoHD. I do not plan on using both TiVoHDs simultaneously and therefore do not want to rent a second MCard. I want to use the same MCard in both TiVoHDs, but obviously not at the same time. Will I be able to swap the MCard back and forth between both TiVoHDs without calling Comcast support each time?