  Problems solved? Pulsar research must be considered - 35 years after the
detection of pulsars - a mature science, where the basic questions have been
raised and discussed. One would hope that many if not all generic and important
problems have found some kind of answer and that scientific work can
concentrate now on specific details requiring more in depth investigation. We
know, however, that this picture is not true. Even well studied areas did in
the past not always lead to a general accepted model and some were investigated
at the beginning with enthusiasm but left behind.
  This paper will concentrate on one narrow topic, pulsar radio spectra. It is
the attempt to work out, what features are now generally accepted, but also
what features are still in discussion after so many years of pulsar research.
In this sense the paper will enlighten in a personal view those aspects which
are still under discussion.
