Comparison of mean flux densities reported in this paper with those obtained by Bilous et al. (2020). The line of equal flux values is shown by green dashed line. In order to maintain symmetry between the two axes, for the systematic error we take a range from 50 to 200% of the equal flux value (green area). Red triangles show the flux density upper limits when a pulsar was detected only by FR606 LBA (triangle is pointing down), or only by LOFAR Core (triangles are pointing left). Note that for the upper limits for the LOFAR Core we used the value of 3σ, where σ is the nominal uncertainty on the flux following Bilous et al. (2016), while for the FR606 upper limits, we used Eq. (1) from the present paper.