RF amplifier for the 10 metre amateur band

The VN66AF manufactured by Siliconix has quite a few advantages, over its rivals; good value for money, in terms of price per watt, high dielectric strength and exceptional gain. It also has a low tendency to oscillate. The most common appli- cation for VMOS FETs is in power amplifiers, but, that is not a reason to discount them for any other use. They have been used successfully in pre- amps, and RF amplifiers. In this 12... 15 V particular case it is used as an RF amplifier for the 10 metre amateur band (26 ... 30 MHz). Small transmitters of around 200 mW can be transformed into reasonably powerful ones delivering between 2 and 3 W by using the circuit described here. The design is fairly straightforward. The fixed filter network positioned at the output, suppresses noise by as much as 55 dB. If the coils are constructed to the specifications outlined in the parts list, then the filter will not require calibration. Obviously experienced hands may wish to change the specifi- cati...