audio vco

Hi!

I have a pll with a PIC and SAA1057 the frequency range is 500 to 1800KHz. I was searching for a suitable VCO for this. But it seems that most of the am vco's are with crystals.
Are there any schematics to be used with this pll?
I have found this schematic(see attachement) but this only transmits RF and i don't know how to modulate sound
Thank you

Exar company makes several VCO ICs that can run in the audio range.

I want to make one AM transmitter :D which is capable of transmitting in the frequency range 500 - 1800 KHz

Well! After 10 years let me update you.
I am using a TDA1072 as a vco and a MC1496 as a modulator.