Suppressor grid modulation uses a pent code in a class C modulated amplifier wherein the modulating voltage is applied to the suppressor which is biased sufficiently negatively. It provides linear modulation up to eighty percent modulation depth. Screen grid modulation is applied at the screen grid. The distortion produced is low. In the collector modulation method the modulating voltage is applied in the collector circuit of tuned class C amplifier in push pull arrangement. It has the merits of high linearity of modulation, high collector circuit efficiency and high power output per transistor.Square law modulation methods makes use of non linear current voltage characteristics of diodes or triodes and are suited only for use at low voltages. Square law diode modulation uses non linear region of the current voltage dynamic characteristics of a diode--Tymon Hytem has worked in the electronics feild for the past 15 years. He enjoys helping people decide on electronic gadgets from telephones to XM Radio and choosing the perfect XM Satellite Radio system for their needs.