We consider the widespread hypothesis that coherent curvature radiatio
n is responsible for the radio emission of pulsars. The comparison of
energy conservation and the published data and luminosities explicitly
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 neit
her the observationally deduced emission heights nor the observed radi
us to frequency mapping can be reproduced by this mechanism. Our argum
entation is in accordance with the more general critics (e.g. Melrose
1992) that no adequate bunching mechanism has been identified for cohe
rent curvature radiation. We present 5 examples (0329+29, 0355+54, 054
0+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 frequ
ency example the faintest radio pulsar 0655+64 of the Taylor et al (19
93) sample.