A amplifier of force RF for the FM , is always essential for the amateur that wants it strengthens some small transmitter, that likely already it has manufactured or has been supplied ready. The present circuit can give 50-60W RF force of expense, with control smaller than 15-20W in the region of frequencies of FM, that is to say in the 88-108MHZ. Transistor that we selected for this manufacture is the BLY90, that has gain 5dB.
If all they are it includes, you connect the exit of your transmitter (15-20W) in input the amplifier. The exit of amplifier him you will connect in some charge (dummy load) or in the aerial, through bridge stagnant waves. Supply with tendency 11-15V your amplifier (power supply it should gives current 4-5A). Regulate the 4 variable C1-C4, until you take the biggest force of expense. The amplifier is ready.

filter if pcb tube