limlim500

Hey, i am building the medium range transmitter (http://www.electronics-lab.com/projects/rf/025/index.html) I am having problems because i have built it from the schematic and it will not work. the only difference is i used a 5-65pf trimmer instead of a 4-40pf transmitter since they dont sell them and that was the closest match up. would this make a big difference? i've used all the same parts and transistors etc, can anyone help me figure out whats wrong? also is it meant to transmit in AM or FM? and for the audio input would a headphone input be ok? any help is appreciated. liam.