APS-4 Radar unit

Hi everybody!

I translate books about (mostly) WWII planes
from Polish to English and sometimes I need some help with
phrasing, or to better understand how something works, etc.

An example would be about the radar unit (APS-4) used on the
F4U-2 night fighter. How was the distance indicated on the
screen, what are the English words on the indicator lamps that
showed whether you were above or below the enemy plane, how was
it indicated when you were level with the enemy, and what are
the names of the two range modes (0-0.5 mi. and 0.5-3 mi.) for
that unit.

If any body here can help me with this, I'd really appreciate
it.

TIA
--
Petros
Ap' ola prin ipirche o Logos