I finally managed to connect a PIC to the mains and send some basic X10 commands to a couple of receivers without using a PL513/TW523. The trick was in getting the X10 signals out of the PIC, pre-modulated at
120 KHZ to avoid using an external oscillator.
And, thanks to you Dave, I had a number of PLC coupling techniques to refer to.
Thanks again.
Regards,
Anand