R.F. head (in a radar set)
A term used to refer loosely to the assemblage of radar frequency components, sometimes including the antenna system and usually including the head amplifier.
Reference: B.S. (modified)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Centre of buoyancy
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM