2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/175807We show that there are physically relevant situations where gravitational waves do not inherit the frequency spectrum of their source but its wavenumber spectrum.4 pages, 2 figures. In v2 minor corrections and a full sentence changed in section III in the paragraph about turbulence. Version accepted for publication by PRDAstrophysicsGeneral Relativity and Quantum Cosmologytext