Group items tagged

This RF power amplifier is based on the transistor 2SC1970 and 2N4427. The output power is about 1.3W and the input driving power is 30-50mW. It will still get your RF signal quit far and I advice you to use a good 50 ohm resistor as dummy load. To tune this amplifier you can either use a power meter/wattmeter, SWR unit or you can do using a RF field meter. RF Amplifier Assembly Good grounding is very important in a RF system. I use bottom layer as Ground and I connect it with the top with wires to get a good grounding. Make sure you have some cooling at the transistor. In my case I put the 2SC1970 close to the PCB to handle the heat. With good tuning the transistor shouldn't become hot. RF Amplifier Printed Circuit Board You can download a pdf file which is the black PCB. The PCB is mirrored because the printed side side should be faced down the board during UV exposure. To the right you will find a pic showing the assembly of all components on the same board. This is how the real board should look when you are going to solder the components. It is a board made for surface mounted components, so the copper is on the top layer. I am sure you can still use hole mounted components as well. Grey area is copper and each component is draw in different colors all to make it easy to identify for you. The scale of the pdf is 1:1 and the picture at right is magnified with 4 times. Click on the pic to enlarge it. Low-Pass Filter Some of you might want to add a low-pass filter at the output. I have not added any extra low pass filter in my construction because I don't think it is needed. You can easy find several homepages about low pass filter and how to build them.

project of circuit potency lineal RF amplifier with BLY90 for Fm transmitter or vhf transmitter Circuit for lineal amplifier for VHF with power source and printed circuit board, using the transistor Bly90 It is to be used as amplifier of potency of RF in the high strip of of the power source that should be capable to supply a tension of 13 volts with a current of 10 amperes. it demands right care in the assembly of the source. Terrified armored transformer, and three shocks of RF to filter the components of high frequency. XRF1 and XRF2 are 30 you turns of wire 25 AWG in a nucleus of ferrite of 1 cm of diameter and 5 cm length. It can use one of a source at/atx bad, it is easier. XRF3 are 100 you turns of wire 25 AWG in a ferrite nucleus and 1cm of diameter for 5cm of length. Or use an usually found in the exits of sources ATX’s. something around 100µH. The capacitors C1, C2, C3, C4 should be ceramic of 600 V or more and the capacitors of 10nF are for 100v. RX cannot be of wire. Power supply circuit for the rf lineal amplifier Orijinal görüntüsünü görmek için buraya tıklayın. 512x223 px. About the transistor BLY90 The Transistor BLY90 was developed to work in the classes THE, B and C, with 12.5V current of 8A. For applications above 175MHZ. Below we have the diagram circuit of the amplifier using an only transistor BLY90. All capacitors should be ceramic. The resistor of 10Ω for 1 w should not be of wire, the entrance impedance and exit is of 50Ω , soon it should be linked with cable of 50Ω . It should be observed the legal restrictions as the operation of that equipment type. Diagram circuit of the project for the rf lineal amplifier Orijinal görüntüsünü görmek için buraya tıklayın. 522x297 px. Printed circuit board for the lineal amplifier with bly90 Below we have the drawing of the printed circuit board of the transmitter, observe that the components are mounted beside the copper and with the terminals the shortest possible, use heatsink in BLY90. lists of material for assembly of the lineal RF potency amplifier Power Supply RX = 22KΩ 1W C1,C2,C3,C4 = 100nF 600V Ceramic C5,C6,C7,C8, =10NF 100V C9 = 100NF C10 = 4700µF C11 = 2200µF D1,D2,D3,D4 = 1N5401 or equivalent. XRF1,XRF2 = 30 turns of wire 25 AWG in nucleus of ferrite of 1cm diameter for 5 length. Optional, use a shock of RF of a computer source, those of the entrance of the net. XRF3 = 100 turns of wire 25 AWG in a nucleus of ferrite of 1 x 5. T1 = Transformer of 12 Volts for 10 Ámperes with screening. Several = box, plugs, cables, etc. Amplifier of RF Q = BLY90 R = 10Ω 2W C1 =15PF C2,C3,C4,C5 = 100PF C6 = 470NF C7,C10,C11 = 470PF C8 = 47PF C9 = 56PF C12 = 22PF CV1,CV2 = TRIMMER 4 – 40PF CV3,CV4 = TRIMMER 60PF MAX. L1 = 3 turns of wire 24 AWG with diameter of 7mm, nucleus of air. L2 = Shock of RF of 0.22µH. L3 = 15 turns of wire 24 AWG around a resistor of 47Ω x 2W (it doesn’t serve as wire) L4 = 3 turns of wire 24 AWG with diameter of 7 mm, nucleus of air. L5 = 1 turns (sees fig. below for details) L6 = 3 turns of wire 24 AWG with diameter of 7 mm., nucleus of air. L7 = 4 turns of wire 24 AWG with diameter of 7mm, nucleus of air. Several = printed circuit board, antenna, cables, heatsink, box, etc. Detail of L5. That project is just for ends of didactic test, that doesn’t implicate in any responsibility of the idealizator about the non operation or illegality of operation of the equipment.