Should work fine. You'll just lose the Advanced Program Guide information. Remember to reset your system to "no dish." Might leave the subscription card in it, too. It's supposed to work OTA without it, but once it's been activated, there have been a few reports of it not wanting to cooperate without that card inserted.
Plus with the card in and the dish connected, you will get any software updates. Not that there's been a plethora of those...
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