Active AM Radio Antenna Amplifier Preamplifier Circuit
Active AM Radio Antenna Amplifier / Preamplifier Circuit The antenna amplifier circuit has a part count of about 40, using the following active parts: 2 NPN transistors (BC548's), 1 MOSFET (BF981), 2 Varicap diodes (KV1235), as well as a 6v2 zener-diode. there is and a 330uH (micro Henry) inductor / coil, which can be modified for operation on other frequency bands. Designed to work with a telescopic whip antenna, the amplifier circuit operates in the typical AM / MediumWave band of 550 - 1650 kHz (kilohertz), with a power requirement of 12 Volts DC. The circuit also has a gain control feature, so weather signals can be amplifier more, if need be. This amplification alteration is provided via, RV1 The amplifier circuit's output impedance is 50 Ohms, which is the standard for all of radio receivers, so it ought to work well along with your AM receiver. Notes This circuit is designed to amplify the input from a telescopic whip antenna. The preamplifier is designed to cover t...