plese give me idea on data receiver

 

hello sir ,
i am trying to make a project of rf data transmission .then give me an idea of..
if i used 555 ic in the transmiter end then what ic used in the receiver end

 

we can replace 2n3904 with bc547 , yes or no?
and
we can replace 2n3906 with bc557 , yes or no?

 

Take a look at the Clare M-8888 DTMF transceiver (www.clare.com). One chip, two functions.

--Rich