Dish is currently offering a bunch of free previews of channels that may not be in the packages you subscribe to.
Current free previews include Comedy Central (Ch. 107), FOX Movie Channel (Ch. 384), MGM HD (Ch. 385), Animal Planet (Ch. 184), and HDNet Movies (Ch. 130) all through Thursday, February 28.
BBC America (Ch. 135) is available free until Tuesday, February 26.
Starting Friday, Feb. 15 the provider begins a free preview of EPIX (Channels 292, 380-382) through Monday, Feb. 25.
And, the last weekend of the month you can get a free preview of NBA TV and NBA League Pass from Saturday, Feb. 23 through Sunday, February 24.
NBA TV can be found on Channel 156, while NBA League Pass takes up Channels 5000-5061 and 470 on Hopper.