Hi Moray:

Those 500 Meg ohm resistors are too high to have any effect on the Q of a tuned circuit. Even 10 to 20 Megohms is pretty high. We could do a circuit simulation to show what effect the resistors would have but it maybe just as easy to connect the componets and measure the result.

The resonant frequency of a tuned circuit is equal too:

Fr = (2 * Pi)/(LC)^1/2

Where Fr = the resonant frequency
Pi = 3.1416
L = the circuit inductance
C = the capacity

The term (LC)^1/2 power is actually the square root of the (LC) product.

Hope this helps.

Ron