well, another interesting thing that i found today is the wing shing S8050 works and delivers R waves in a distance of abt 2Kms! And has alot better stability than c1959!, i didn't download its datasheet but a site says it has 1W power!, i wonder how come these transistors in an ordinary TO-92 packages while the same watt rated transistor (like.2n2219a,2n3866) come in metal cases? New technology? But to achive 2Km range,i had to power the transmitter with a 9V supply and a two meters long antenna, another important thing that i found today is i could power it using a mains transformer with lm317 regulator and abt 7 of those green 'sack like' caps to avoid hum completely!, anyway guys, i think we should design a circuit as mvs_sarma said, but i might need your help.