The radio source 1422+202 (4C 20.33) is a steep spectrum radio source identified with a quasar of redshift 0.871 and visual magnitude 17.65 (Véron & Véron 1987). It was recognized as a member of the Compact Steep Spectrum class of sources by Mantovani et al. (1992) in their investigation of the arcsecond scale structure of a sample of 19 steep spectrum sources showing variability at low frequency. Reported as a variable source at 408MHz by Fanti et al. (1983), 1422+202 did not change in flux density with time at higher frequencies (Padrielli et al. 1987) for several years. In the VLA image at 5GHz (Mantovani et al. 1992) 1422+202 exhibits a structure elongated north-south, with a faint region of emission off-axis close to the southern bright hot spot.
We present here new VLA A-array observations at 8.4 and 15GHz and VLBI
observations at 1.6GHz made with the European VLBI Network (EVN).
The VLBI observations
were designed to apply directly the wide field mapping technique to the
data set from the correlator. However, due to technical problems during the
data recording at some stations we choose to analyse the data by
applying the phase referencing technique.
The main aim was the detection of
both the core and the southern hot spot which lies 
8
away,
as suggested by beating in the fringe visibility on
the baseline Effelsberg-Westerbork obtained in a previous EVN pilot
experiment at 1.6GHz. The absolute positions, relative to the calibration
source OQ208, obtained for the detected components
in the VLBI field of view, were then compared with those achieved
in the VLA image at 15GHz.
Combining the VLA and VLBI observations we investigated some of the issues regarding the nucleus of 1422+202. Before these observations it was not clear where this source fits in the CSSs scheme, which were the physical processes causing the helical structure shown by the jet, the nature of the asymmetrical structure and the cause of the variability at low frequency.