Jano OM8AAK is the author of an interesting article on PA, which he managed to compile for a few crowns. The base is a hybrid PA Mitsubishi M6779H2, which was bought on the stock exchange for fifty crowns. The PA gives approximately 20W of power in the 70cm band.
Connecting the entire PA is very easy thanks to the hybrid IO:
After switching on, it is necessary to match c3-c7 at the input and at the output for that reason alone, that the integrated circuit is mainly intended for frequency 450-480 MHz. This setting adjusts its operating frequency downwards. It heats up especially during longer cranking.
If you need something more powerful and have more integrated circuits, go to the site http://www.qsl.net/dl4mea/70cmpa.htm.