3-YEAR MONITORING OF A SAMPLE OF FLAT-SPECTRUM RADIO-SOURCES AT 327 MHZ

Results of a 3-year monitoring programme at 327 MHz with the Ooty Synt hesis Radio Telescope are presented. The majority of the sample consis ts of BL Lac objects, high-optical polarization quasars (HPQ) and low- optical polarization quasars (LPQ). In addition, a few known variable sources, GHz-peaked spectrum sources and compact doubles were also add ed. Including an additional set of 36 control and calibrator sources, a total of 82 sources were observed at roughly 3-month intervals for a bout 3 years. We find 19 variable and 6 possibly-variable sources. How ever, the observed variability in the BL Lac-HPQ-LPQ subsamples does n ot seem to be influenced by their optical properties.