[sdiy] 40Mhz triangle core on FR4 substrate!

[karl dalen]

Im trying to scream up a 8Mhz triangle VCO core 
to 40Mhz on a FR4 PCB substrate, does anyone know
of a online PCB design tutortial for RF somwhere?

How high up can one design "easy" with single and doubble
sided FR4 substrate? 2 layer ought to create capacitive
problems at certain frequency. I used to know this but 
i have completely forgotten!! 

I mean, how far can one design in frequency without
having to take to much care of the properties of 
the FR4 material?

KD