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18dB FM/UHF/VHF High Power TV Booster (TV Signal Amplifier) Circuit Diagram using 2sc3355

Today, we introduce simple & small High Power FM/UHF/VHF booster (TV signal amplifier) circuit. It covers the frequencies from40MHz to 900MHz and boosts the VHF signals up to 23dB and UHF signal up to 18dB. An External power supply not necessaryfor this circuit, it operates using the coaxial cable as feed line. It’s very easy to build, but try to maintain the terminals of componentas close as possible to discharge involved frequencies. Make this circuit on good quality PCB for best performance.

Frequency response – 40MHz – 900MHzTypical Gain – 18dBMaximum output level – 90μVImpedance – 75Ω

Components:D1, D2 – IN4148D3, D4, D5, D6- IN4007C1, C4 – 100PF (101) CeramicC2 – 2.2PF CeramicC3 – 1000PF (102) CeramicC5 – 470μf / 16V ElectrolyticC6 – 1000μf / 16V ElectrolyticC7 – 0.24μf (224) CeramicR1 – 82K/0.25WR2 – 1.5K/0.25WR3 – 270Ω/0.25WR4 - 120Ω/0.25WQ1 – 2SC3355T1 – 230V – 12V/300mA step-down transformerL1, L2 – Wire thickness – 0.5mm (25 SWG / 24 AWG) Diameter – 5mm Turns - 8L3, L4 – Wire thickness - 0.5mm (25 SWG / 24 AWG) Diameter – 3mm Turns - 25

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MAR-6 VHF-UHF wide band amplifier circuit

design electronic project

This wide band amplifier circuit is designed using the MAR-6 IC manufactured by Mini Circuits . ThisMAR-6 VHF-UHF wide band amplifier circuit will providing stable gain of at least 9dB up to 2GHz.Because the MAR-6 is designed to receive its power via the signal output pin, it’s very suitable for use as amasthead amplifier. It requires about 3.5V DC, at a working current of around 16mA.As you can see in the circuit diagram this masthead amplifier electronic project , require few external electronicparts , so if you will use SMD components you’ll have a very compact design . With power applied, the LEDshould glow reassuringly and you should be able to measure about 6.8 - 7V DC at the end of R1 nearer IC2 andC5 . If the LED doesn’t glow and you get no voltage reading, chances are that you’ve wired the DC input withreverse polarity .If the LED doesn’t glow but there’s almost the full plug-pack voltage present at R1, you’vealmost certainly wired the LED in backwards.

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Active Antenna AA-7 HF/VHF/UHF,3-3000MHz

by Fred Blechman and Tony van Roon

"Lift those hard-to-hear signals out of the mud withthis handy receiver accessory."

If you have a shortwave or high-frequency receiver or scanner that is struggling to capture signals with a short,whip antenna, and you'd like the kind of performance that a 60-foot longwire antenna can provide but lack thespace to put one up, consider building the AA-7 HF/VHF/UHF Active Antenna described in this article. TheAA-7 is a relatively simple antenna that is designed to amplify signals from 3 to 3000 MegaHertz, includingthree recognized ranges: 3-30Mhz high-frequency (HF) signals; 3-300Mhz very-high frequency (VHF) signals;300-3000MHz ultra-high (UHF) frequency signals. Those bands are typically occupied by shortwave, ham,government, and commercial radio signals.

Active Antennas:In its simplest form, an active antenna uses a small whip antenna that feeds incoming RF to a pre-amplifier,whose output is then connected to the antenna input of a receiver. Unless specifically designed otherwise, allactive antennas are intended for receive-only operation, and thus should not be used with transceivers;transmitting into an active antenna will probably destroy its active components. A well designed broadbandactive antenna consider field strength of the desired signal (measured in microvolts per meter of antenna length),atmospheric and other noise, diameter of the antenna, radiation resistance, and antenna reactance at variousfrequencies, plus the efficiency and noise figure of the amplifier circuit itself.

Circuit Description:Fig. 1 shows the schematic diagram of the AA-7, which contains only two active elements; Q1 (an MFE201N-Channel dual-gate MOSFET) and Q2 (a 2SC2570 NPN VHF silicon transistor). Those transistors providethe basis of two independent, switchable RF pre-amplifiers. Two double-pole double-throw (DPDT) switchesplay a major role in this operation of the AA-7. Switch S1 is used to select one of the two pre-amplifiercircuits (either HF or VHF/UHF). Switch 2 is used to turn off the power to the circuit, while coupling theincoming RF directly to the input of the receiver. That gives the receiver non-amplified access to the auxiliaryantenna jack, at J1, as well as the on-board telescoping whip antenna. With switch S2 in its power-on position,the input and output jacks are disconnected and B1 (a 9 volt battery) is connected to the circuit. With switchS1 in the position shown in the schematic, incoming RF is directed to the HF pre-amp circuit built around Q1(an MFE201 N-Channel dual-gate MOSFET). The HF pre-amp operates with an exceptionally low noise level,and is ideal for copying weak CW and singe-side band signals. When S1 is switched to the other position, thecaptured signal is coupled to the VHF/UHF pre-amp built around Q2 (a 2SC2570 NPN VHF silicontransistor), which has excellent VHF through microwave characteristics. With the on-board whip antennaadjustable to resonance through much of the VHF-UHF region (length in feet = 234 divide by the frequency inMHz), the VHF/UHF mode is ideal for indoor and portable use with VHF scanners and other receivers. Eithermode can be used when tuning 3-30 MHz HF signals. The VHF/UHF pre-amp offers higher gain than the HFpre-amp, but also has a higher noise level. You can easily choose either amplifier for copying any signal; ofinterest--just try both positions. The RF gain control (R5) can be used to trim the output of either amplifier.

Caution: The AA-7 is not intended for transmitting operation (be it Ham, Maritime, or CB); if it is usedwith a transceiver of any kind, make sure it is not possible to transmit by accidentally pressing a mike buttonor CW keyer. Transmitting RF into the AA-7 is likely to ruin one of both of the transistors in the circuit.

Construction:

The AA-7, which can be built from scratch or purchased in kit form from the supplier listed in the Parts List,was assembled on a printed circuit board, measuring 4 by 4-11/16 inches. A template for the pcb board isshown in fig. 2. You can either etch your own board from that template, or purchase the circuit board or thecomplete kit of parts (which includes the pcb and all parts, but not the enclosure). The kit comes with a16-page kit instruction manual that gives step-by-step assembly instructions and contains additionalinformation not covered in this article. Kit assembly time, working slowly and carefully, should take less thanan hour. Most of the parts specified in the Parts list are standard components and can be procured throughconventional hobby electronics suppliers. However, some parts--J1, J2, S1, S2, and R5-- have particularphysical mounting dimensions; the Printed Circuit Board is designed to accept these particular parts. Inaddition, Q1 and Q2 can be hard to find; however, it is possible to make substitutions provided that you canfind a supplier. Suitable replacements for Q1 and Q2 are given in the Parts List.

The telescoping whip antenna screw-mounts to the board; the screw provides contact between the printedcircuit board traces and the antenna. To save time and trouble locating and ordering hard-to-find parts, a SpecialParts Kit is also offered by the supplier listed in the Parts List.A parts placement (layout) diagram for the AA-7's printed circuit board is shown in figure 3. When assemblingthe circuit, be especially careful that transistors Q1 and Q2, and the electrolytic capacitor C4, are oriented asshown.Although not shown in the schematic (Fig. 1) or the layout (Fig. 3) diagrams, an optional led power indicatorcan be added to the circuit. Adding a power indicator to the circuit allows you to tell at a glance if the circuit ison; leaving the circuit on, even though the AA-7 draws only about 0.7 mA, will eventually discharge thebattery. Of course, adding an led will increase the current drain to by about 7 mA, but the red glow makes itobvious when the unit is on.

If you decide to include the LED indicator in your project, power for the indicator can be easily taken from theswitched 9-volt DC terminal of S2 (center terminal, right side, looking at the top of S2). Simply connect thepositive voltage to the anode (longer wire) of the led and connect her cathode lead through a current limitingresistor of about 1000 ohm to a ground point on the printed circuit board, or as the author did from the frameof R5. Mount the led at any convenient point near the switch.Although not supplied with the kit, a custom plastic enclosure (with front and back panels) or a regular 'hobby'case of some sorts, and knobs for the switches and gain control can be purchased from most local electronicsstores or mail-order.

Test and Use:Prepare a coaxial cable to connect the RF output of the AA-7 to the antenna input of your receiver or

scanner. One end of the interconnecting cable must be terminated with an RCA phono plug; the other endconnector depends on the target receiver or scanner. With some receivers, the only practical connection is toclip the output of the AA-7 to the receiver's antenna, although that connection won't be as effective asconventional (ground-return type) coupling.To increase signal strength, especially for the lower frequencies, you can connect a simple supplementaryportable antenna of any design (a dipole, random-length wire with Earth ground, a bigger vertical whip of somekind, etc.) to the circuit. Just use a small-diameter coaxial cable terminated in an RCA plug for mating with J1.No alignments are required. If you're using the whip antenna, simply connect the output of the AA-7 to yourreceiver, with the unit turned off (that's the bypass position) and the RF gain control (R5) turned fullycounter-clock wise. Turn on the receiver and tune-in a weak station. Switch S2 on, and adjust the gain control

clockwise to increase the output signal. Toggle S1 back and forth to see which setting gives you the bestresults. Don't be surprised if the gain control overloads the receiver; if so, back it off.

Troubleshooting:The fact that there are two independent pre-amplifiers in the AA-7 makes faults easier to diagnose than withmany other devices. If a problem occurs, only at one setting of S1, concentrate on that part of the circuit. If theproblem is common to both settings, the components and the connections common to both preamps should bechecked. Make sure the jumper wires are in place!There are other characteristics or phenomena associated with preamplifiers and active antennas that does notmean that your circuit is malfunctioning. For example, if you have strong AC hum in the HF setting, theantenna is too close to an AC cord or powerline. HF signals may be clearer at the VHF/UHF setting than in theHF setting. Why? Although either pram may be used for HF, the signal strength will be greater with theVHF/UHF pram. However, the HF signal-to-noise ration is better with the dual-gate-MOSFET-based pram.Try both and use the best for your particular receiver conditions.Some portable receivers not enclosed in metal cases may break into oscillation when connected to any RFpreamplifier. Try reducing the AA-7's gain and make sure that good grounds are provided with theinterconnecting coax cables. A preamplifier will intensify any problems due to poor receiver design:overloading, images, or any other problems with selectivity and image rejection.

Parts List and other components:

Semiconductors:

Q1 = MFE201, SK3991, or NTE454. N-Channel, dual-gate MOSFET (see text)Q2 = 2SC2570, NTE10, NTE107. NPN VHF/UHF silicon transistor (see text) Note: If you use the NTE107 as a replacement, make sure to insert it correctly

into the pcb. The orientation is different than as shown on the parts layout diagram. (e-c-b seen front view for NTE107). See this Data Sheet

Resistors:All Resistors are 5%, 1/4-watt R1 = 1 Mega Ohm R2 = 220KR3,R6 = 100K R4 = 100 ohm R5 = 10K potentiometer, (pc mount)

Capacitors:C1,C2,C5,C6 = 0.01uF, ceramic disc C3 = 100pF ceramic disc C4 = 4.7 to 10uF, 16WVDC, radial lead electrolytic

Additional Parts & Materials: B1 = 9-volt alkaline batteryS1,S2 = DPDT PC mount pushbutton switchJ1,J2 = PC mount RCA jack ANT1 = Telescoping whip antenna (screw mount) MISC = PCB materials, enclosure, enclosure, battery holder and connector, wire, solder, etc.

If you wish to purchase a parts kit and pcb, [CLICK HERE]

Fig. 1. "The AA-7 Active Antenna contains only two active elements: Q1 and Q2 (a 2SC2570 NPN VHFsilicon transistor), which provide the basis of two independent, switchable RF preamplifiers."

Fig. 2. "The AA-7 was assembled on a printed-circuit-board (PCB), measuring about 4 by 4-11/16inches. A template for the printed-circuit-board is shown here. Note that it may not be to scale.

Parts assembly diagram (layout) is shown in Fig. 3 to make soldering the unit together a breeze!"

Fig. 4. shows the finished assembly without the enclosure. Make sure the antenna-hole in the enclosure isin-line with one on the pcb. On mine I used a stud with thread on both sides to enable me to use differentlength antenna's; all I have to do is unscrew and screw another antenna back in without taking the AA-7 apart. Iused a 9-volt battery tray which allows me to replace the battery without opening up the case, but the regularbattery clip and battery works fine. As you can see from the pictures, this is a nice one-evening project.

I fully support this project. since my unit has been in operation for quite a few years now and still running onthe same battery. Power consumption if minimum. Most parts can be obtained via your local electronics store.I will answer all questions but via "Tony's Message Forum" only. This Forum can be accessed via the mainpage, gadgets, or circuits page.

Copyright and Credits:Source: "Electronics Hobbyist Handbook", Spring 1994. Copyright © Fred Blechman and GernsbackPublications, Inc. 1994. Published with permission from Gernsback. (Gernsback Publishing no longer exists).Document updates & modifications, all diagrams, PCB/Layout drawn by Tony van Roon.Re-posting or taking graphics in any way or form of this project is expressly prohibited by internationalcopyright laws.

Back to Circuits pagePage Copyright © 1995 - Tony van RoonProject Copyright © 1994, by Fred Blechman

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Wideband PreAmp's for HF/VHF/UHF

RE-HFA1MAR6 Wideband VHF/UHF/SHF monolithic PreAmp based onMARx-series

The MAR6 (MSA-0686,0685,0885) is a high performance silicon bipolar Monolithic MicrowaveIntegrated Circuit (MMIC) housed in a low cost, surface mount plastic package.This MMIC is designed for use as a general purpose 50 W gain block. Applications includenarrow and broad band IF and RF amplifiers in commercial and industrial applications.The MSA-series is fabricated using HP’s 10 GHz fT, silicon bipolar MMIC process which usesnitride self-alignment, ion implantation, and gold metallization to achieve excellentperformance, uniformity and reliability. The use of an external bias resistor for temperatureand current stability also allows bias flexibility. It is a Cascadable Silicon BipolarMMIC Amplifier.

MAR 6 and MAR 8 Features (MSA-0685 & MSA-0885)• Frequency range from DC to 2GHz• high gain, 22.5 dB (31.5dB MAR8) at 100 MHz, reduces component count• high power output, +12.5 dBm typ.• low noise

• improved stability• protection against power supply transients• exact footprint substitute** MAR-8 and MSA-0885• 3.2...4.2 volt @ pin 3•

Schematic with external power supply

Components:40Mc...2GHzIC1 = MAR-6 or MAR-8 or MSA-0685 and MSA-0885 respectivelyIC2 = 78L05C1 = 56pFC2 & C3 = 100pFR1 Bias* = 120 (rev1.3)C4 & C7 = 4.7uF/25vC5 & C6 = 100nFC8 = 560pFL1 = 3 a 4 turns of 0.2 Cu wire through a ferite beadL2 = 2,7uH or 4 turns of 0.2 Cu wire through a ferite bead (optional, static blead)D1 & D2 = 1N41481Mc...1GHzC1 = 1000pFC2 & C3 = 2200pFL1 = 100uHL2 = 47uH (optional, static blead)

PreAmp features:• High gain, 22.5 dB (31.5dB MAR8) at 100 MHz, 20dB @ 1GHz• Can be used for TV and ATV reception too.• Frequency range from +/- 30Mc to 2GHz (1Mc to 2GHz see above components list)

• Voltage indepentend (8...20volts)• Low current drain• Static drainage (L2)• Output protection (D1 D2 inverted diodes) for accidental TX• 50 Ohms input and output impedance• Voltage indepentend (8...20volts)• Dynamic range 14.5 dBm - 20dBm MAR 8• VSWR in 1.5 out 1.8• Noise < 3dB

* Biasing R1 =120 Ohms @ 5v270 Ohms @ 9v470 Ohms @ 12v

Tips:The best place to put a pre-amplifier is with out a doubt as closest to the antenna as possible.If possible, directly mounted at the feeder (dipole) and using phantom-type powering of theamplifier. The RF/DC splitter comes inside the shack just before your receiver.

Keep the connections as short as possible @ RF IN and RF OUT and keep them in 50 Ohmsimpedance starting at the leads from the IC. Mount it in a shielded casing.

With use with an transceiver: This preamp is protected to a certain degree for accidental TX(+/- 5watt) at the output, but no guarentee is given that your MAR-6 will survive. So make theneeded precautions to prevent this from occuring when used in a TX type situation (likebetween your antenna and transceiver). Use a RF-sensing circuit instead.

When using it only with a receiver: you can leave out the parallel inverted diodes and C3.

L2 can be left out if your antenna has already some type of static bleeder build in (or DCshortened, like a folded dipole etc...). If you don't know for sure, just take your Ohm-meterand measure between the centre and the braid of the coax which should read something like <1k or so. Inverted parallel diodes are also used to bleed of static build up. Test this with yourdiode tester. Ever so now and then (mostly with older type of RX verticals) a neon bulb is usedhence never can be measured. Just leave L2 as it is (can't do much harm in any case statedabove anyway).

Schematic with phantom power supply using the coax as feedline

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This wideband antenna preamplifier has a gain of around 20 dB from 40 to 860 MHz,covering the entire VHF, FM, commercial, and UHF bands.

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comprei o cabo RGC 213, que no meu caso foi o DLC 213 premium, da datalink, que no fundo é a mesmacoisa...

fiz o cálculo de medida para cada gomo..

= (v * c) ÷ (2 * f)

= (0,82 * 299792458) ÷ (2 * 2441000000)

= (245829815,56) ÷ (4882000000)

= 0,050354325186399016796394920114707(multiplica por 100)

= 5,0354...

v = velocidade do cabo ou velocidade de propagação - nesse link tem essa velocidade dos cabosda datalink Data Link.c = velocidade da luz = * 299792458 km/s.f= freqüência do sinal = 2441000000 (2.4 Ghz).

então cada gomo terá que ter 5,03 cm! Isso no meu caso, de acordo com o cabo que usei e deacordo com a potência do meu roteador!!

não é cada gomo ter isso.. na realidade 5,03 cm é a distância que o início de um gomo terá doinício do outro gomo, veja o gráfico abaixo..

é isso aí.. espero ter contribuido..demorou cerca de 4 horas pra fazer!!

e funciona mesmo!

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Faça Sua Antena Omni

Um bom tipo de antena bem fácil de fazer é a antena omni, a antena omni tem como principalcaracterística irradiar os sinais de RF em todas as direções, por isso é uma antena muitoutilizada para curta e média distância.

A proposta deste texto é dar condições para que possa ser montada uma antena omni de acordocom as necessidades do montador, sendo assim, em razão da disponibilidade do material e danecessidade do ganho em dB, pode ser feita uma antena de três dB a dez dB, obviamente quemaior for o ganho desejado, também será usado mais material.

De qualquer modo, para ganho de três dB, devem ser usados quatro elementos, nesse caso aantena irá ficar com pouco mais de 30 centímetros.

Quem desejar ganho de seis dB, deverá usar seis elementos, para 9 dB devem ser usados 16elementos, para 10 dB devem ser usados 20 elementos, observe que com vinte elementos aantena terá seu tamanho um pouco maior do que um metro e trinta centímetros.

Quem optar pela construção da antena para maior ganho, se usar um Acess Point de 400 mW,poderá irradiar o sinal para aproximadamente 7 quilômetros com visada, isso é uma previsãoaté bem pessimista para antenas com visada.

Mas também poderá nem chegar a um quilômetro, se a altura em que a antena for instalada forbaixa, e se houverem obstáculos no caminho, pois o sinal poderá nem chegar, mas isso não écaracterística da antena, mas sim da faixa de freqüência (UHF) que é praticamente a linha dovisual.

Dependendo do ganho que você deseja para sua antena, você vai precisar de tantos elementosiguais ao da figura abaixo, os elementos são feitos com o próprio cabo coaxial que é cortado empedaços com medidas certas e descascado uma parte da capa do cabo coaxial para possibilitara soldagem.

Lembrando que em se tratando de freqüências altas, mexer com equipamentos e antenas,requer muito cuidado e todo e qualquer detalhe é importante, principalmente em se tratando demedidas.

Cada elemento deve ter 6.7 centímetros (67 milímetros), deve ser tirada a capa de um centímetrode cada lado do elemento, de forma que fique em cada uma extremidades um centímetro livre,deve ser tirado um pedaço da capa que protege o fio malha, ele é muito importante, pois agiracomo elemento inversor de fase do sinal captado e emitido.

A montagem deve ser feita com cuidado, as soldas devem ser feitas rápidas para não ficar umabicheira (solda fria) no local da solda. O detalhe das medidas é mostrado na figura abaixo:

Note que é soldado fio central no fio malha, e no estágio seguinte, o fio malha é soldado no fiocentral, assim deve ser quantos elementos forem necessários na antena, mas devem serrespeitadas as medidas conforme a figura acima: O elemento da antena fica na realidade com57 milímetros(5.7 cm), separados um do outro por 5 milímetros (0.5 cm), note que noselementos da antena já foi descontado o fator de velocidade do cabo coaxial RGC 213, que é de0.85, por isso, siga as medidas indicadas para esse tipo de antena.

Note também que o final da parte de cima da antena tem um elemento que é ligeiramentediferente o tamanho:

Essa antena foi calculada para operar na freqüência central na faixa utilizada por redes Wlan,

note que a faixa utilizada começa em 2.4000 e termina em 2.4835, para obter a freqüência centralbasta que seja realizado o seguinte cálculo:(2.4000 + 2.4835) / 2 4.8835 / 2, e teremos comoresultado 2.441 GHz, e é nosso objetivo montar a antena para essa freqüência.

Essa antena é projetada para trabalhar em meia onda, e o fator de velocidade do cabo coaxialRGC 213 já foi incluído nos cálculos, em todo caso, relembro que o fator de velocidade para ocabo coaxial RGC 213 é 0.85.

Conforme deve ser de seu conhecimento, a velocidade de propagação de RF no vácuo é de300000 km/s, mas a propagação através de outro meio que não seja o vácuo sofre redução develocidade.

Para cada material tipo de material utilizado, o fator de velocidade terá um valor diferente, comonosso material é o cabo coaxial RGC 213, o cálculo para obter a velocidade da propagação deRF através do cabo é o seguinte: 300000 x 0.85, e como resultado,nesse caso, temos 255000Km/s.

E a antena pronta deve ficar com aspecto parecido com o da figura abaixo:

E para quem gosta de conectores que compre dois, um macho e um fêmea, eu soldo a antenano cabo coaxial, faço da mesma forma que faço com os elementos da antena, tiro um centímetrode capa com a malha e tiro um pedaço do plástico da capa do cabo coaxial para permitir asoldagem.

Como dados técnicos adicionais: o comprimento total de cada seção de cabo coaxial é ½ ondamais 15 milímetros, onde o resultado é 67 milímetros, note que arredondei o valor, que narealidade era 67.2 milímetros.

Para ficar bem claro, esclareço que o condutor central do elemento feito com cabo coaxial deveser de 10 milímetros expostos de cada lado de cada seção.

A malha que reveste o elemento feito de cabo coaxial é importante, as soldagens devem serfeitas rapidamente para não deformar a malha e para evitar que a malha venha a sair do lugar.

O último elemento que vai à ponta, aquele do final da antena, fique atento, porque ele temmedidas diferentes.

O último elemento é acrescentado para fazer o acoplamento inicial da antena, se você montaruma antena com seis elementos, esse elemento final será o sétimo elemento.

Depois de tantos detalhes, acho que chega, então finalmente, para montar a antena é só irsoldando com cuidado os elementos, de maneira que o dielétrico de um elemento fiqueexatamente a 5 milímetros de distância do dielétrico do outro elemento.

Depois da antena montada é só colocar tudo em um pedaço de tubo de PVC do tamanho da

antena recém montada, desde que seja hermeticamente fechado, eu uso um tampão e um canode PVC de 25, duas abraçadeiras e um parafuso para prender o cabo coaxial, isso é o quepossibilita que a antena seja instalada em ambientes externos.É isso, boa sorte.

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Antena WiFi biquad com antena SKY

Entusiastas do wireless vêm transformando antenas a anos. Estabeleceram uma marca demais de 200 km, usando velhas parabólicas de 3m. O que é muito se comparado com osmodernos pratos, tipo sky. O prato parabólico permite focalizar a ondas de rádio para uma antenadirecional. É utilizada uma antena biquad, pois é bastante tolerante a erros de montagem e temum rendimento muito bom. No final a biquad é acoplada a uma velha sky e… eureka,conseguiram detectar APs a mais de 12km.

Construindo a ANTENA:

As antenas biquad podem ser construídas a partir de materiais comuns, o que é bom, contudoalgum material você terá que comprar.3060000000054037 A coisa mais importante aqui é opequeno conector N, não me perguntem onde tem. Aqui em Joinville eu sei, na sua cidade…

O “N-conector” é padrão na maioria das antenas comercial e você pode conectá-los aos seusdispositivos sem fio usando “pigtails”.

O cabo longo é um pigtail com conectores RP-TNC para N-macho que será usado para conectara antena a um AP Linksys WRT54G.

O curto é um RP-MMCX para N-macho para que possamos ligar a antena a nosso cartáo PCISenao 2511CD PLUS EXT2 WiFi.

Também se utilizam 10 metros de cabo coaxial WBC 400 pora não ter de se sentar com o pratono colo. Além é claro, da valha antena SKY.

Trevor Marshall construiu uma das primeiras antenas WiFi biquad encontradas na internet. Aquise foi um pouco mais fundo nas instruções encontradas em martybugs.net e aqui estão asmatérias-primas com que começar:

Um fio padrão de núcleo rígido, utilizado em instalações elétricas residenciais. Como osexecutores do projeto não tinham uma placa de circuito impresso disponível, utilizaram umachapa fina de cobre colada a um suporte plástico, mas é mais recomendável e prático, utilizaruma placa de CI virgem.

O primeiro passo na construção do elemento foi descascar e cortar um padaço de 244milímetros de fio.

O fio foi marcado em intervalos de 31 milímetros e começou a fase das dobras. Ele deverá serdobrado em forama de um duplo diamantae. Tenta-se alcançar a maior aproxiomação de cadaperna a 30,5 milímetros.

A maneira mais fácil de fazer curvas muito acentuado no fio de cobre sólido é usar dois pares dealicates.

Como fica o elemento com todas as curvas completas:

Em seguida, um quadrado de 110 milímetros de lado, de plástico, para apoio da chapa de cobreou diretamente um quadrado de circuito impresso virgem com as mesmas medidas deverá serconfeccionado.

Agora deve-se soldar dois pedaços de fio de cobre ao pino N, começando pelo fio externo, poisprecisa de um aquecimento maior para uma boa solda.

Após esfriar, fixe o pinco (conector-N)a base de cobre e solde a parteexterna a placa (quadrado de 110milimetros de lado).

O próximo passo é a solda do laço,elemento em forma de diamanteduplo, aos fios verticais. O elementodeve ser apoiado em calços de 15 milímetros para garantir a

posição correta.

Em seguida, corta-se o excesso dos fios verticais e fica assim:

Para fazer a do nosso elemento ao prato, a maneira mais fácil é modificar o lbnf original,utilizando partes do mesmo. Esta é a aparecncia inicial.

Após a remoção da caixa e dos elementos internos, ficamos com isto:

Anexamos nosso elemento a essa caixa e fica assim, com o cabo coaxial conectado:

Prontinho para anexar no prato da sky:

Se sua antena é do tipo com offset, ficará como na figura. Para saber se está apontada para ohorizonte, deverá ser alinhada a 45º e montada num tubo de suporte com inclinação de, também45º. Parece apontada para o chão mas está certo. Se for sem offset (modelo em que o elementofica no centro da parábola) então deverá ser apontada diretamente mesmo.

Segundo os desenvolvedores, o resultado é exelente e conseguiram se conectar a 12km desitancia.

Este eu ainda não teste. Assim que montar a minha informo.

Para os que já montaram a sua sinhantena, explicada neste site, segui uma serie de fotosanimadoras:

2leep.com

Originally posted 2009-08-17 15:02:02. Republished by Blog Post Promoter

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WIFI 16dBi Super Antenna Pictorial

http://antenaswireless.aarca.com/2011/11/01/que-tal-fazer-uma-antena-wifi-de-16-dbi-baratissimo-e-facil/

Que tal fazer uma antena WiFi de 16 dBi baratíssimo e fácil?

Que tal fazer uma antena WiFi de 16 dBi baratíssimo e fácil?

Encontre esta antena wireless, no artito: Que tal fazer uma antena WiFi de 16 dBibaratíssimo e fácil? e achei incrível. Parece realmente muito fácil de fazer e encontrei muta coisa boa sobre ela na internet. Ainda nãotestei, mas tem tudo para funcionar bem.

E vejam. Pela lista de material é bem simples mesmo:

Quais são os materiais?1 placa de cobre, latão ou metal comum fino de 12x12cm1 Chassi de conector BNC1 Conector de cabo BNCplaca de isopor na densidade do styrofoam de 35mm de espessuraFio elétrico de 1.5mm2

No site você vai encontrar até um vídeo para ajudar.

http://www.tecnomodo.com/2009/03/que-tal-fazer-uma-antena-wifi-de-16-dbi.html

Q ue tal fazer uma antena WiFi de 16 dBi baratíssimo e fácil?

Nós postamos aqui há alguns anos atrás um hackeamento da antena WiFi tradicional para obter um ganho no sinal. Agora a intençãoé demonstrar que podemos criar uma antena inteira com preço acessível.

Quais são os materiais?1 placa de cobre, latão ou metal comum fino de 12x12cm1 Chassi de conector BNC1 Conector de cabo BNCplaca de isopor na densidade do styrofoam de 35mm de espessuraFio elétrico de 1.5mm2

Mais informações você pode achar na página do instructablesfonte: instructables.

http://www.instructables.com/id/10--WIFI-16dBi-Super-Antenna-Pictorial/

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High Gain Wi-fi Helical Antenna

Presented here is a versatile, durable, and rather unique wi fi antenna that can greatly extend your wireless networking range andspeed. When built with ten or more turns, this helical wi fi antenna vastly outperforms the cantennas and wi fi wok tops often seenon the internet. A short five turn helical makes a very good feeder for a wi fi parabolic dish antenna. A special quality of this antennais that it radiates and receives a circularly polarized signal. It does not favor vertically or horizontally polarized signals. Thus, thisantenna works well with wi fi signals reflecting off of buildings, moving vehicles, or antennas oriented at odd angles. Circularlypolarized signals are less affected by rain, so you can reach distant access points in stormy weather. There is a 3 dB loss of gain whenusing this antenna with linearly polarized signals; high gain is maintained by making the antenna long - at least ten turns forstand-alone usage.

Design parameters for this helical wi fi antenna were calculated using the online helical antenna calculator and was inspired bysimilar designs used for the AMSAT OSCAR 40 satellite.

PARTS REQ UIRED FO R THE WIFI HELICAL ANTENNA:

one square piece of copper sheet metal or single sided PC board for a ground plane.1.one PVC kitchen drain tailpiece (3.8 cm / 1.5" diameter) to hold the helical windings2.six 1/8" plastic cable ties3.a length of copper circuit tape (adhesive backed, width 3mm or 1/8") or #14 copper wire4.one suitable chassis connector (I used a reverse sma type matching the connector on my adaptor)5.one 90 degree angle bracket with screws and bolts to fit6.

CO NSTRUCTIO N:

Center the tailpiece on the PC board, copper side, and mark the circumference in ink.1.Mark four locations on the circumference, spaced 90 degrees, where the cable ties will hold down the PVC tube.2.Mark one location on the circumference, exactly between two 90 degree markings, where the coaxial connector will bemounted.

3.

At this point you should have a PC board with a circle in the center, four tick marks on the circle at 90 deg intervals, andone tick mark exactly between two others.

Drill 1/8" holes on the inside and outside of the circumference at the cable tie locations.4.Drill a hole directly on the circumference suitable for the chassis connector. Carefully measure and drill other holes for thisconnector if necessary.

5.

Drill four holes, spaced 90 deg apart near the bottom end of the PVC tailpiece.6.Drill holes to accomodate a small 90 degree corner bracket.7.Drill holes on opposite side of board to accomodate USB wi-fi adapter that will be affixed with cable ties.8.Tin the copper around the connector mounting hole, then mount the connector. Clip the center pin to keep it only longenough for connection to the helix windings.

9.

Cut out a notch to accomodate the connector; it should clear center conductor, but avoud cutting out excess PVC material.10.Feed cable ties through from the back side of the board, through holes in the tube, and back through the board. Tighten thecable ties, making sure the tube is firmly held to the copper ground plane.

11.

Use a ruler and the edge of a sheet of paper to create a template for positioning the windings on the PVC tube. Distance zerorepresents the ground plane, then add the feedpoint distance, then ticks matching the turns spacing. Use the template to markyour tube on both the feedpoint side and the opposite side.

12.

The objective is to precisely wind the helical wi-fi antenna using an accurate guide...

Space the turns 2.5 cm on atube of 3.9cm outer diameter.

Here is a table used for my prototype helical wi-fi antenna and its connector. Note that turn 1 starts at 0.8 cm (height above groundplane of feedpoint). Turns Spacing is 2.5 cm, and the diameter is 3.9 cm (close enough for 1.5" PVC tailpiece). If your connectorcan be trimmed to allow a feed connection closer to the ground plane than 0.8CM, then simply run the helix as low asnecessary. Most impartant is keeping the proper spacing between turns.

Spacing=2.5cmDiameter=3.9cm

(fits 1.5" PVC tailpiece)Turn # Height (cm) above

groundplaneHalf TurnsHeight (cm)

1 (feedpoint) 0.8 2.052 3.3 4.553 5.8 7.054 8.3 9.555 10.8 12.056 13.3 14.557 15.8 17.058 18.3 19.559 20.8 22.0510 23.3 24.5511 25.8 27.0512 28.3 29.5513 30.8 32.05

Carefully wind the helix, using circuit tape or wire, then solder to center conductor of chassis connector. Double check againstthe turns template. Polarization will be right-handed if the turns spiral clockwise (looking outward from feedpoint).

13.

Attach the angle bracket and wi-fi adapter, making sure all parts are secure and ready for service, as seen in the images below.14.

The high gain wi-fi helical antenna.10 turn stand alone version

Cable losses avoided bymounting wi-fi adapterat base of antenna.

Short wi-fi helix feeding a long rangeparabolic wi-fiantenna.

At this point, helical wi-fi antenna is ready for its smoke test...plug in the cables and look for some signals! Theoretical gain of theprototype helical was about 18 dB over an isotropic radiator; it beat my biquad by about 7 to 13 RSSI units, and indeed seemedless sensitive to polarization and rainfall. Signals still seem to fluctuate much from second to second. If your antenna is functioningsatisfactorily at this point, I suggest spray painting three layers of clearcoat onto the windings and groundplane for stability andcorrosion prevention.

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