A short-pulse transmitter is a communication device standard in Colonial Vipers, capable of transmitting in scrambled code.
Captain Apollo asks Lieutenant Boomer to radio Galactica on the short-pulse transmitter after discovering Robber, Slayer and Tanya on an abandoned settlement, in the hopes of informing Galactica that Starbuck is alive and that there are no Cylons (deleted scene, The Long Patrol).