Well, according to [this summary of Voyager's telecommunications systems][1] by JPL's Deep Space Communications and Navigation Systems Center of Excellence (DESCANSO), the uplink frequency (Earth to Voyager) is 2113.3 MHz. Here's the downlink (Voyager to Earth) frequencies of both Voyager 1 and 2:

[![enter image description here][2]][2]

So Voyager 2 uses a frequency of 2295 MHz (S-band) or 8415 MHz (X-band).


  [1]: https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_ed.pdf
  [2]: https://i.sstatic.net/o5ziO.png