RF amplifier circuit diagram
This RF amplifier circuit is a very simple and is designed to work for 10 meters band (26 ... 30 MHz) reserved for amateurs.
By making this RF amplifier circuit small power transmitters of 200 mW, can be transformed into a power transmitters reasonable, ranging between 2 and 3 W. The circuit is very simple. Network output filter suppresses noise by at least 55 dB.
Amplifier is suitable for almost all types of transmissions, because of the possibility of adjusting the drain current of FET's by P1. For linear applications (AM and BLU), drain current must be adjusted to 20 mA. If is used for FM-CW, P1 will be adjusted so that no current will not flow through the drain rest. For this case, the idle current is 200 mA and between 300 mA.
Coils are made on cases with a diameter of 9 mm. Care should be taken to wound as tight turns without any space between them.
Coils should be made as follows: L1 = 12 turns enamelled 0.6 mm copper, L2 and L4 = 5 turns 1 mm enamelled copper, L3 = 8 1 mm enamelled copper coils.