Has anyone heard of any cases where the radio pulses of a well-observed
radio pulsar suddenly stop being detected? I know that X-ray pulsars,
called X-ray transients, are observed to "turn on" and "shut off",
sometimes periodically and sometimes randomly. But has a radio pulsar
with a period of 0.001 sec to 4 sec ever gone silent?

Thanks for any information on this topic.

Rob Oldershaw