OKye first the chip 88422 i am using is certified to be used in pakistan. ALso i have make a couple of experiments on the telephone lines and till now i am not getting any problmes and the proff is that my telephone is working FINE TILL NOW after those experients.


second i test the dialer on the local telephone exchange. there is a a telephone on the exchange 111. wheneven i dial this number i got the ring on the telephone. but i can not dial any other number on the exchange.

pls don't tell me that my circuit is not generating other tones.

here is the telecommunication standards in pakistan
http://www.angelfire.com/ak/shahzad73/PS.pdf


and here is the circuit of MH8880 and MH88422 from zarlink

http://www.angelfire.com/ak/shahza...MT8888.pdf


i'm not good in analog affair so can some body look at these and let me know if there is any differene between DTMF levels or durations what my circuit is generating and what is required on the telephone exchange in pakistan

please give me any lead where should i go.

thnaks
Shahzad