HF 70 watts power amplifier DIY kit. Part 1.

Some time ago I ĥave bought a DIY kit - the 70 watts HF power amplifier. The reason for buying is simple: I have a low power transceiver (20 watts) and sometimes it is required to make it stronger to reach more distant stations not being able to hear my quiet voice. And although 70 watts is not dramatically bigger than 20, I decided to buy it - the price is reasonable and the overall complexity of joining all together is pretty low.