This is Wide band high frequency amplifier circuit, a Wide frequency band between 75-150 MHz, Using transistors, a PNP amplifier. To enhance the signal strength. Before the receiver of the phone. Or FM radio or amateur radio.
If high-frequency signals, in particular, its VHF. The booster circuit is one, serves to amplify the signal strength only.
Operation of the circuit
High-frequency range VHF, inductive antenna, to the emitter pin of the transistor Q1. so circuit held, in conjunction with the bass, a nice low output impedance. You can use a special access code 50 ohms, the antenna on the circuit at all.
The Signal at the Q1 will be expanded to increase. And sent to a tuner or receiver to the receiver.
The L1 coil wire enamel No. 24 SWG, thousands of rounds of 10, inside diameter 3 mm. And the coil L2 wire number. Thousands of 13 turns, diameter 5 mm. Stent both as a non-core, or an air core.
The power supply is +5 V, this circuit while current is 2.5 mA. If the components to use. Should be based on the antenna. And design of high frequency printed circuit boards as well.
How to assemble circuits
The assembling circuit onto the universal PCB board as Figure 2 May have problems, the interference inserted come in, If assembly circuit to actually use. Should have a basic antenna and PCB design in high frequency reasonable.
The components list
Resistors size ¼ W +5%
R1, R2: 18K
R4: 220 ohm
C1, C3: 0.0056uF 50V
C2: 56pF 50V
C4: 5.6pF 50V
Q1: BF324___PNP Transistors
L1: is 10 turns of 24 SWG enamel coated magnet wire wound with an inside diameter of about 3mm. no core.
L2: is 13 turns of 24 SWG enamel coated magnet wire wound with an inside diameter of about 5 mm. no core.
The Universal PCB board
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