Thanks a lot Mr Hans Van Pelt Mr Andy Neil and Mr Erik Malund for your informative advices I will now try to search for information on ring buffer also I had put active filter on both the in put and out put I even put a peak and hold circuit at the input of the adc0804 too. Yes I had put a jnb ti,$ and a jnb ri,$ in my code but that cause worse problem ,I guess that’s because I had to share betwix tx and rx. In my reasoning audio signal should exits in continous uninterrupted stream but at the rate my circuit performs time sharing of tx and rx signals become a real problem and I hadn’t fully realize yet but the ring buffer might help solve my problem if I can store data from conversion while tx and retrieve it during rx I might be fine anyhow micro controller is a great thing to learn especialy when you are retired and gets tied to one spot like me,just reading all the posts and sometimes post some question make a guy fell less lonely.
Thanks a lot every body.