Crystal based Hartley oscillator...

Hi,

I want to construct one AM transmitter which can transmit high frequency(High bit rate) signals.. For example,DTMF signals..


First step i want to build one oscillator which will provide good wave form out put(Clear wave form).. I am planning to go for Hartley.. It seems if we design it using crystal,it will yeild better reslut.. So can u please suggest what modifications i can do in basic hartley oscillator to make it into a crystal based one..

If any link regarding that topic,please post it here..