Mitsubishi Electric 
 
M50117CP 
 
CMOS
18 pin plastic DIL 
 
Function: PCM Receiver 
 
These were used by Plessey Australia in remote control equipment many years ago and were used in conjunction with the M50115 PCM Transmitter chip
I probably have a datasheet, supplied on request
            Tested as described in the description
This item is not returnable, UNLESS not as described