We present data for a valved antimony cracker for use in solid-source molecular beam epitaxy. Both aspects of this source, the cracker and the valve, are characterized. In particular, the valve is shown to exhibit excellent performance in terms of control and reproducibility. As a demonstration of the capabilities of this source, continuously graded layers from GaAs to GaSb were grown by using the source in conjunction with a valved arsenic cracker. We discuss the influence of this source and other growth parameters on composition, structure, and morphology of these graded layers.