The East-West arm of the 'Northern Cross' radio telescope of the Bologna Univer sity has been used to observe 14 planetary nebulae at the frequency of 408 MHz. The half-power beamwidth of the instrument is 4' E-W by 100' N-S. For the very weak sources studied here, confusion permits a positional accuracy of 2 s E-W by 15' N-S. As the resolution limit is about 0-2 flux units, the measured flux densities of the weakest sources are accurate to 30%. Constant declination scans were made through the

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... ptical positions given by Thompson et al. (1967), and at adjacent declinations spaced at intervals of 30', in order to restore the N-S diagram of the sources. As calibration objects for flux density and position the sources 3C 48, 3C 71, 3C 119, 3C 216, 3C 237, 3C 245, 3C 446, and CTA 102 were used.