Hi Marc, actually the Halpha V&R and V/R are high variable parameters with a certain periodic behavior. Please have a look to the investigation we recently published at IBVS No. 6156
http://astrospectroscopy.de/media/files/IBVS_6156-02.pdf
The source of the variability of Halpha, originating from an accretion region around the hot companion, remains unclear and the time sampling of these Halpha observations are too sparse to permit a meaningful period analysis. See our IBVS publication No. 6198:
http://ibvs.konkoly.hu/pub/ibvs/6101/6198.pdf
Best wishes, Ernst