Have 622-counts as 2, and 2 stand alone units. Upgrading to the 722 and wanted to use the 622 to replace the 510 in my office to get TV on my HD Big sreen monitor and still have the TV with the exercise bike. After 1 hour on phone, Loyalty Dish tells me no can do! Advised to purchase own unit on ebay and hook up. Said there would be no additional charges. i'm confused and beginning to feel stupid. Can anyone enlighten me? i'm all ears. Paying about $ 150/month for everything.