We present a model for the generation of Langmuir waves in the outer heliosphere. We further invoke the nonlinear interaction between the Langmuir waves resulting in electromagnetic radiation, at the second harmonic of the plasma frequency, which is able to leave the source region. This model can provide a quantitative explanation of the remote observation of radio emissions at 2--3 kHz by the Voyager plasma wave instrument in the outer heliosphere. If these radio emissions are generated by Langmuir waves, the Langmuir wave electric fields at the remote source are estimated to be 100--200 &mgr;V m-1. Location of the source of the emissions at the meridian passing through the apex is consistent with the recent direction finding on Voyager 1.