Zagnut,

You can calculate the frequency using the following formula:

Time(in seconds)= Resistance (Ohms) X Capicatance (Farads)

This will give you the cycle period in seconds.

For example using a 500 ohm resistor and a 0.47mf capacitor:

500 X .00047 = 0.235 seconds. Dividing 0.235 into 1 gives 4.255 cycles per second(Hz).