Sounds like the sub-ether radio in Hitchiker's Guide, where you had to sit infuriatingly slowly not to change channels: http://www.technovelgy.com/ct/content.asp?Bnum=1329
A loud clatter of gunk music flooded through the Heart of Gold cabin as Zaphod searched the sub-etha radio wave bands for news of himself. The machine was rather difficult to operate. For years radios had been operated by means of pressing buttons and turning dials; then as the technology became more sophisticated the controls were made touch-sensitive--you merely had to brush the panels with your fingers; now all you had to do was wave your hand in the general direction of the components and hope. It saved a lot of muscular expenditure, of course, but meant that you had to sit infuriatingly still if you wanted to keep listening to the same program.
Zaphod waved a hand and the channel switched again