Construction of the amplifier is relatively simple however; special attention should be given to thermal conductivity around the output transistors. Normally such an amplifier is driven with a 10 watt exciter having a  low pass filter in the output. It may be necessary to have an input attenuator and matching network to present a 50 ohm resistive load to the exciter. If the input and output filters are of the same design, oscillation of the PA at VHF frequencies may occur. It is adviseable to ensure that if the input filter is capacitative then the output filter should be inductive and vice versa.