The work that is presented is based on a new flux limited 200 mJy sample
of compact {\it flat} spectrum radio sources (March\~a {\it et al}. 1996).
The original sample consists of a total of 55 objects plus 2 that do not meet
the sample selection criteria but were considered interesting to study.
The main objective of this study is to complement the work already done on the sample, namely investigating the 1.4 GHz radio properties of 18 of the original sources. The 18 sources were divided into two large categories: one of {\it BL Lacs} and another of galaxies that, in (March\~a {\it et al}. 1996), manifested intermediate properties between a {\it Seyfert}-type and a {\it BL Lac} type object. Radio core polarizations, extended luminosites and the {\it R} parameter (which is the core luminosity divided by the extended luminosity) were calculated, as well as study of the radio source morfology at 1.4 GHz. In light of these parameters, any systematic diferences between the two categories were registered in order to compare with the diferences as were seen in (March\~a {\it et al}. 1996).
After some brief considerations of AGN theory, we present the preliminary results of this study including the first radio maps obtained of the sources at 1.4 GHz.