  We consider the widespread hypothesis that coherent curvature radiation is
responsible for the radio emission of pulsars. The comparison of energy
conservation and the published data and luminosities explicitely proves that
coherent curvature radiation cannot be the source for the radio emission of
pulsars for frequencies below a few GHz. At higher frequencies coherent
curvature radiation can be ruled out because neither the observationally
deduced emission heights nor the observed radius to frequency mapping can be
reproduced by this mechanism. Our argumentation is in accordance with the more
general critics (e.g. Melrose 1992) that no adequate bunching mechanism has
been identified for coherent curvature radiation. We present 5 examples
(0329+29, 0355+54, 0540+23, 1133+16, 1916+10) of pulsars whose high frequency
(larger than 1.4. GHz, up to 32 GHz) luminosities are well known, and as a low
frequency example the faintest radio pulsar 0655+64 of the Taylor et al (1993)
sample.
