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Amplificador de RF de transmissão (BFt)
Esquema
Material
Placa de circuito impresso virgem de 15 x 15mm
1 Transistor 2N3904 mas pode ser BC547B BC547C BC548B BC548C.
2 capacitores ceramicos 100nF (podem ser entre 47nF e 220nF isolação maior que 25V)
1 capacitor ceramico 10nF ( isolação maior que 25V)
1 resistor de 560R 1/8W (pode ser 1/4W)
1 resistor de 2k7 1/8W (pode ser 1/4W)
1 resistor de 68R 1/4W
1 resistor de 10R 1/8W (pode ser 1/4W)
1 resistor de 100R 1/4W (pode ser 82R ou 120R de 1/4W)
1 indutor (microchoque) de 22µH
1 bobina bifilar (vide modulo B3 )
Layout
Montagem
1. Cortar placa e serrar as ilhas
2. Soldar o transistor ilhas 1 (base) 2 (coletor) 3 (emissor)
3. Soldar resistor entre ilhas 1 e GND.
4. Soldar resistor entre ilhas 1 e 4
5. Soldar resistor (68R) entre ilha 3 e GND.
6. Soldar resistor de 10R em pé na ilha 3
7. Soldar capacitor entre a ponta do resistor e a terra (GND)
8. Soldar bobina bifilar.
9. Soldar capacitor entre ilhas 4 e terra (GND).
10. Soldar resistor e indutor entre ilhas 4 e 6.
11. Soldar capacitor entre ilhas 6e terra (GND).
Fotos / Pictures
TX RF amplifier (BFt)
Schematics
Parts List
Copper clad PC board 15x15 mm
1 Transistor 2N3904 may be BC547B BC547C BC548B BC548C.
2 100nF (104) Disc cap (between 47nF - 220nF greater than 25V)
1 10nF (103) Disc cap (greater than 25V)
1 560R 1/8W resistor (or 1/4W)
1 2k7 1/8W resistor (or 1/4W)
1 68R 1/4W resistor
1 10R 1/8W resistor (or 1/4W)
1 100R 1/4W resistor (or 82R or 120R 1/4W)
1 bifilar coil (look module B3 )
Layout
Building
1. Cut the PC board and make islands with a hand saw removing the copper layer.
2. Solder transistor island 1 (base) 2 (collector) 3 (emitter)
3. Solder resistor between islands 1 and GND.
4. Solder resistor between islands 1 and 4.
5. Weld a resistor (68R) between islands 3 and GND.
6. Solder resistor (10R) one side aerial at island 3
7. Solder ceramic cap between 4R7 (aerial) and ground (GND).
8. Solder bifilar coil.
9. Solder cap between islands 4 and ground (GND).
10. Solder resistor between islands 4 and 6.
11. Solder cap between islands 6and ground (GND)
Pictures