Unsubscribe Device?

I have two Kindles. Can I remove one from Calibre's control, while retaining another? If so, how is this done? I am now using a Kindle Fire HD for receiving news using Kindle. I'd like to prevent my Kindle Keyboard from receiving the same news publications. [When I turn on wireless connectivity on the Kindle Keyboard it starts receiving the news publications intended for the Kindle Fire.]

Thanks
John