Table of Contents
Antenna amplifier signal booster circuit diagram, this HD TV UHF wideband amplifier(Ultra High-Frequency amplifier) has a total gain of 10 to 15 dB in the 400 – 850 MHz domain frequency, so it can be used where the tv signal is weak.
For this, UHF antenna tv amplifier to work correctly, you need to cut the components pins as short as possible. This antenna tv amplifier or uhf wideband amplifier need to be built inside of a metal box and then connected close to the TV antenna.
About the amplifier circuit UHF digital TV antenna booster 10 to 15 dB
It is an RF amplifier for the UHF band which includes digital TV that uses this frequency band. The main component is the RF transistor 2sc3358, but you can also use an equivalent.
The signal coming from the antenna enters through connector J3, passes through the high-pass filter formed by C1, L3 and C2, is amplified by the transistor Q1, passes through a high-pass filter at the output and follows the cable to the power supply board. There it is connected to connector J4 by capacitor C12, blocking the DC voltage from the power supply.
The booster should be installed close to the antenna, to amplify the signal picked up by the antenna. The board should be mounted preferably in a metal box and should be protected from rain and sun. The power supply board can be located close to the TV, so as to have easy access to a power outlet.
The power supply uses a 9 to 12V /200mA transformer and a diode bridge + 1000uF capacitor. L5 blocks the RF signal from traveling through the power grid, the DC voltage travels through the antenna cable to the booster board, L2 blocks the RF signal from traveling through the transistor feed. L1 prevents the RF signal from traveling through the power supply. With these inductors, we have capacitors that form the low-pass filter.
Adjust trimpot R5 to set the best signal level for your needs.
The connectors should be type F, in the SMD version, no connector was added on the board, they should be screwed on the booster box and soldered at the points indicated on the board.
If you prefer, in the SMD version, space has been left for soldering a shielding to isolate the input circuit from the output.
Also in the SMD version you can order the components already soldered, see how to do here.
About the coils:
L1 ,L2 – 2 turns of 22 AWG wire, 3 mm diameter or inductor 0805 in SMD version
L3, L4 – RF shock of 10µH or 10 turns of 24 AWG wire wound on a ferrite stick, or inductor 0805 of 10uH ≥ 200mA in the SMD version.
Prototype pictures
Antenna amplifier signal booster circuit diagram schematic
PCB layout Antenna amplifier signal booster circuit diagram
SMD Version
The power supply is a simple 12V stabilized source. The antenna TV amplifier can be connected directly to the power supply through coaxial cable of the TV antenna, but you need a 10 – 100uH coil on the supply line. The TV set will be connected to the UHF amplifier through a small coupling capacitor.
Adjusting is easy, just bring the P1 to the middle and then adjust it until you obtain the best TV image quality.
BOM for assembling a UHF Digital TV antenna booster amplifier
Last Update: 28/11/2021 20:36
| Part | Valor | Descrição | Quantidade |
| PTH or SMD 0805 resistors | |||
| R1 | 2.2k | Red, red, red, gold (222) | 1 |
| R2 | 470 | Yellow, violet, brown, gold (471) | 1 |
| R3, R4 | 1k | Brown, black, red, gold (102) | 2 |
| R5 | 4.7k (472) | Trimpot | 1 |
| PTH or SMD 0805 Capacitors | |||
| C1, C2, C3, C4 | 10pF (10p) | Ceramic Capacitor | 4 |
| C5, C7, C11 | 10nF (103) | Ceramic Capacitor | 2 |
| C6, C8 | 1nF (102) | Ceramic Capacitor | 2 |
| C10 | 1000uF/25V | Electrolytic Capacitor | 1 |
| C12 | 470p (471) | Ceramic Capacitor | 1 |
| C18 | 10uF/16V | Electrolytic Capacitor (Tantalum Capacitor) | 1 |
| Semiconductors | |||
| B1 | DB107S or equivalent | SMD Bridge Rectifier | 1 |
| D1, D2, D3, D4 | 1N4004 or equivalent | Diode | 4 |
| Q1 | 2SC3358 or equivalent | Transistor | 1 |
| Miscellaneous | |||
| ANTENNA (ANT, ANT-) | F-type connector | Connect the antenna | |
| OUT (OUT, OUT-) | F-type connector | Connect the drop cable. | |
| Power (power, GND) | F-type connector | Connect the cable coming from the antenna. | |
| TV (TV, TV-) | F-type connector | Connect to TV | |
| CN1 | AC power | Jst Xh 2-Way Connector, 2.54 mm pitch or equivalent. | 4 |
| L3, L4 | 33 nH | Inductor, see text (SMD 0805) | |
| L1, L2, L5 | 10uH | Brown, black, black, gray (SMD 0805) | 3 |
| Solder, Wires, PCB, Box to house the circuit, 12V 250mA transformer | |||
Download the files for this assembly, includes PCB in format PNG, PDF, POSTSCRIPT and GERBER
- Download PDF datasheet of the 2SC3358 transistor
- Download DB107S rectifier bridge PDF datasheet, DB101S, DB103S, DB103S, DB104S, DB105S, DB106S
- Download PDF datasheet diode 1N4001, 1N4002, 1N4003, 1N4004, 1N4005, 1N4006, 1N4007
nao consigo encontrar o transistor sc 3358, informe outro similar. grato
The amperage is very low, i think no more of 50mA.I’am using a simplified circuit with this transistor to get more gain before of input of a cheap amplifier. 5db+20db?
OLÁ TONI EU TENHO UMA DÚVIDA SOBRE O CIRCUITO DO AMPLIFICADOR DE TV UHF A ALIMENTAÇÃO E 12 VOLTS MAIS A ÁMPERAGEM E NO VALOR DE QUANTOS ÁMPERES OU MÍLIAMPERES DA FONTE.UMA OUTRA DÚVIDA O CIRCUITO PODE SER LIGADO A UMA ANTENA EXTERNA OU SERIA A PENAS PARA ANTENA INTERNA.DESDE-JÁ AGRADESSO.