Variability of VLBI components of OQ 208. a) Total flux density variability of OQ 208 observed with the UMRAO 26-meter radio telescope: 4.8 GHz (black), 8 GHz (red), 14.5 GHz (blue). The sum of 15-GHz flux densities of the VLBI components (see Table 1) is represented by green symbols indicating that  ~15% is missed due to lack of short uv-spacings. b) Temporal variations of the flux densities of VLBI components. The flux densities are derived from the model-fitting results listed in Table 1. Two vertical lines mark the peak epochs of NE1 (around 1998.313) and SW1 (around 2003.313). To clearly show the variability behavior of SW1, the flux densities of SW1 have been multiplied by a factor of 10. c) Variation of the 15-GHz flux density of the hotspot NE1 with the component size. The flux density of NE1 experienced a slow rise before epoch 1998.313, followed again by a sharp decline until epoch 2005.473 followed by a slow decline. The component size constantly increases during the whole period. d) Temporal variation of the spectral index of the NE lobe. The spectral indices are calculated from the 15-GHz MOJAVE data and 8-GHz RRFID data at close epochs. A sharp jump of the spectral index occurs around 2006, after which the spectral index steepens significantly.