  We report photometric observations of the hidden symbiotic star SU Lyn in the
optical bands. In five nights we detect a weak flickering in U band with
amplitude of about 0.05 magnitudes. No intranight variations are found in B, V,
g' and r' bands. This is one more indication that the secondary component is a
white dwarf accreting at low accretion rate. We also searched for intranight
variability of a dozen related object (RR Boo, RT Boo, AM Cyg, AG Peg, BF Cyg,
NQ Gem, StHa190, V627 Cas, XX Oph, FS Cet and Y Gem) in which no variability
above the observational errors is detected.
