40-900 MHz TV Signal Amplifier
Here's a small signal amplifier circuit which covers the broad band frequencies from 40 to 900 MHz. These frequencies include TV in VHF and UHF and also the radio broadcasting frequencies in the 88 - 108 MHz FM band. It is connected between the antenna and the input of your receiver and boosts the signals by up to 20 dB.
Technical Specifications -Characteristics
Frequency response: 40 - 900 MHz
Gain: . 20 dB
Maximum output level: 90 uV
Input - output impedance: 75 ohm
The signal amplifier circuit is built around a single transistor a UHF low signal device, the BFW 92. This transistor can operate in frequencies as high as 1.6 GHz, and has a gain of 23 dB. The signal from the antenna is applied to the input of the circuit and through C5 is fed to the base of the transistor. It is amplified and from the collector of the BFW 92 through C2 and C1 is taken to the input of the radio or TV receiver.
The circuit operates off a small 9 V battery which, because of the very low power consumption of the circuit, is going to last for a very long time.
TV Signal Amplifier Printed Circuit Board
Printed circuit board dimensions (4,3cm x 5,4cm)
TV Signal Amplifier Parts List
R1 = 120 Ohm
R2 = 1,5 KOhm
R3 = 270 Ohm
R4 = 82 KOhm
C1,C5 = 100pF (ceramic)
C2,C3 = 1nF (ceramic)
C4 = 2,2pF (ceramic)
D1,D2 = 1N4148 diode
Transistor = BFR90, BFR91, BFW92
Misc = PCB, 6pins, solder, 9V battery clip
L1,2 -= diameter : 5mm, wire thickness : 0,5mm, turns : 8
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