PNR - Panama Republic :

Canal Radio (HPN60) PNR-32
  MARS Howard AFB (AGA0HO) PNR-44
  NDB Chitre - Alonso Valderrama *CHE PNR-51
Panama Aero PNR-20
Panama Intelmar Radio (HPP) PNR-37
TRTC Panama City PNR-25
USAF Albrook (AHF) PNR-43
USNy Balboa (NBA) PNR-41

 

See also for the Panama Canal Zone (PNZ), which became part of the Republic of Panama on October 1, 1979

The HAM-Radio-QSL from HP1XHI (see below) gives a fine map of the Canal Zone Area: