thanks for your reply sir,,i tested with an oscilloscope(used isolation transformer)and checked the wave,,,not so good.impulses are there a lot in sinewave...may be the electrical-rf-noices...but a good news also there, i plugged an old cordless fm intercom to next house(nearly 1/2 km appart frm my house,and pushed the call switch,same time i heared the ring tone in the slave end,,i checked with scope and a clean fm carrier around 367khz recived on the pll input of reciver...this way i sure that plc is possible...these intercoms are old technology..but using zerocrosse with a pic micro i strongly belive this will work...here iam attaching a document of plc...unfortunately source code is not compleated...can you go thru this and guide me to construct one?