The rotor tested was from a Pitcairn PCA-2 autogiro.

A video of the history of the Langley Full Scale Tunnel can be seen by clicking on this link (courtesy of NASA Langley CRGIS). The rotor test appears at time 1:22 in the video.

Source: Full-Scale Wind-Tunnel Test of a PCA-2 Autogiro Rotor, John B. Wheatley and Manley J. Hood, Langley Memorial Aeronautical Laboratory, October 12 1934