Frequency is the number of complete oscillations a wavelength makes each second. Frequency is measured in hertz (Hz) and when there are one million hertz there are called megahertz (MHz). A complete oscillation is when the wavelength reaches the same spot from where it started. To find frequency you use the equation f=1/T where T equals time. T is the time it takes for a wavelength to complete one oscillation. The equation will give how many complete oscillations made in one second, which is frequency.
For a source of frequency I used a 900 MHz cordless telephone. To find frequency I used an oscilloscope, which measures the time for complete oscillations, which is equal to T so I could plug T into the equation. The oscilloscope is hooked up to the antenna of the cordless phone, which is what puts out the frequency.
To cool the antenna of the phone I used ice to cool it down and a thermal blanket to heat it up. After I reached the temperature of the antenna I hooked the oscilloscope to the antenna and then I measured the frequency.