NO buzzing very straight rod, just tried plastic clevis to servo, clevis on rudder wood,
fault applies with bec or 4,8v from external source
losing my patience with this fault.
in many many years of building never had this agro .
Thank you all for the suggestions as to the problem
tried them all (except trying a new servo)could not get my head round the fact that only happened when connected to rudder.
so rummedge the sevo box found a Corona cs-929mg new in box fitted today works fine.
thank you all
Peter