From the schematic http://cie-wc.edu/FREEKItPlans.aspx
I cant get my real life version to work so i'm throwing it up here to analyze it.
* Light represents Microphone
* cap parallel to inductor is suppose to be a trimmer so you can set the radio station then adjust trimmer to find correct value.
1
f = _____________
______
2pi v/ LC
(you never would have go that picture if i wasnt high right now >:p)
(frequency equals the reciprocal of 2 times pi times the square root of the product of L times C)
So with the current values transmission should happen at about 100.6 FM