Problem with EUSART pic16F18877 in async mode
After a carefull re-reading the code and recompiling I discovered where the error was made. I was misled by the information in table 33-4 where SPBRG = 520 in combination with SYNC = 0; BRGH=1 and BRG16= 1; This decimal value can not be used in this format.

//Therefore not: 
 SPRG = 520;
//but:
 SPBRGH = 0x02;
 SPBRGL = 0x08;


After recompilation and testing I found that the information came through correctly; So time to move on with the rest of the program.