I tried to make RF Link , Freq. = 85 MHZ , Modulation is FSK, I build the TX , and the RX was simply A radio whose o/p is 100mW , All i did is disconnectiong the speaker and take the o/p directly to P16F84A Microcontroller and increase the volume tuner . and by monitering the edges of the square wave signals and the duration bet. them i can know if the tranmitted signal is one or zero , and displaying result on LCD ( 1 or 0 ) , i also made a modification that when TX is just opened and no data will be tranmitted TX will send a square wave signal ( i called it signal 2) which the RX will understand it as the TX is opened and NOTHING will be appeared on LCD
The problem is that (TX should be first ON before the RX is on), when TX is turned off , Strange 1's and 0's appeares on LCD as it's from the background noise of the radio , how can i get rid of this problem , i want as there's TX is closed , and RX is opened no o/p on LCD ?
Thanks
signal (0) duration = 555HZ
signal (1) duration = 1KHZ
signal (2) duration = 10 KHZ