PJ0X 1948 Netherlands Antilles
Curacao, Dutch West Indies
Amateur Radio was not authorized in the Dutch Caribbean until 1951. There were perhaps two licensed Government Experimental Licenses issued (PJ3X in 1946 for certain and maybe PJ0X in 1948), and they were allowed to work Amateur stations. As far as I can tell, any others (PJ1BV in 1938, for example) was an illegal/pirate operation. Jossy PJ2MI was working for the licensing authority on Curacao and Sint Maarten during his entire work life (hes now 83 years old), and has confirmed that there was no official Amateur Radio until 1951 for the Dutch islands.
QSL from the estate of W8JIN
Info from K8ND in 2013
Article from September 1946 issue of CQ Magazine, page 35