Tuesday, December 27, 2011
Here the 400W RF power amplifier circuit build using power MOSFET FQA11N90. This Class E RF amplifier will provide approximately 400 watts of RF output, depending on the input voltage and tuning parameters (current). The amplifier utilizes low-cost IXDD414 Driver ICs - one for each two MOSFETs. Transient Voltage Supressors (TVS devices) are applied on the gates, drain bus and modulated DC input towards the RF amplifier to secure the MOSFETs from damage because of accidental overvoltage. The carrier DC voltage ought to be between 40 volts and 50 volts, and not greater than 135 volts at full positive peak modulation.
Monday, December 19, 2011
schematic diagram is the circuit of VHF pre-amplifier for FM broadcasting (frequency 88MHz-108MHz, band II)
The circuit is working with two 2N3819 FET's in cascode configuration. The lower FET works in common source mode, while the upper FET, works in common gate, realising full high frequency gain. The bottom FET is adjustable allowing a peak for a particular station.
Wednesday, November 23, 2011
This is the circuit diagram of 40W wideband RF power amplifier 88 - 108 MHz build based MOSFET MRF171A. The purpose of this circuit is to boost the output power of low power FM broadcast band exciters, a number of these are available commercially, both as kits and ready made.
This design is based on a new MOSFET device, with the attendant advantages of high gain, high efficiency and ease of tuning.
Wednesday, November 9, 2011
Wednesday, November 2, 2011
The above design is very simple FM RF amplifier 8W Watt based 2SC1971 VHF power transistor. The RF Amplifier PCB layout designed for FM broadband 88-108 MHz transmitters using microstripline technique. This 8W RF amplifier circuit provides an appropriate power boost for transmitters with an input of 500 mW.
RF Amplifier PCB
The PCB outline is 77 x 56 mm use FR-4 double sided photoresist epoxy pcb material for best results.
RF Amplifier Construction
All SMD components are 1206 types. Connect the bottom layer (groundplane) on several points (through via's) with the top layer of the PCB.
Wednesday, October 26, 2011
This is a RF amplifier circuit for 10Mhz - 500Mhz input signal. The RF amplifier is using single power transistor BFR540 as the main component to amplify the input signal. The BFR540 is an NPN silicon planar epitaxial transistor in a SOT23 plastic package. BFR540 featured with high power gain, low noise figure, high transition frequency and have gold metallization ensures excellent reliability.
Saturday, October 22, 2011
Monday, September 26, 2011
This is the another UHF-TV pre-amplifier circuit diagram which simpler than the previous UHF TV preamplifier. This circuit is based MPSH10. Alternatives that could be put to use to replace MPSH10 are BF180 and BCY90. The tuned circuit comprising the 15nH inductor and 2.2pF capacitor resonate in the center of the UHF band. The 2.2pF capacitor could be exchanged for a 4.7pF as well as a trimmer capacitor of 2-6pF for better outputs.
Thursday, September 15, 2011
18dB Channel Plus RF amplifier best buy. This RF amplifier product offers a robust power supply and great EMI rejection. It includes grid mounting ears for the Model 2619 Rack-mount Grid. The DA-500A is fully compatible with HDTV Television signals.
The product is as it is described. It amplifies your signal before splitting it, so that you do not have any signal loss. The one thing someone must understand is that it amplifies signal that already exists, it doesn't create signal that isn't there. So if you place it at a point after it has already been split a few times, it wont do anything for you. I live in an apartment, and I guess our cable signal is not the strongest by the time it reaches our apartment. So unfortunately, I don't get the greatest signal ever.
However, when I attempted to split my signal three ways, the signal leading to my computer tv tuner turned out to be extremely degraded before I got the amplifier. Upon adding the amplifier, that signal now comes in as clear as my television does. The television signals seems to be slightly better as well, however if it is better, it is by such a small amount that i can't really say for sure that it really has improved.
This is a great device if you want to split your cable about three ways, assuming that each split causes roughly a loss of about 6.5 db. Any more splitting then that and you are going to face more signal degradation. This device can not be plugged in with your Internet, or it will cause it not to work. I had to rewire it so that my cable Internet and digital phone split before it hit the amplifier. When it was directly plugged through the amp, I lost my phone and Internet.
Besides that, it is a good device to prevent signal degradation when splitting cables. However, if you are not splitting cables and are simply trying to amplify 1 signal to 1 television, its not going to do anything for you, in fact, the only thing that would is a call to your cable company.
18dB Channel Plus RF Amplifier Product Features:
- High-power, low-noise, low-distortion RF distribution amplifier
- Flat response from 50 MHz to 1 GHz; nominal gain of 18 dB
- Suitable for off-air and unidirectional cable TV, VHF, and UHF applications
- Also appropriate for FM, Midband, Superband, Hyperband, and Ultraband uses
Thursday, September 8, 2011
HF Bands QRP RF Linear Amplifier based power transistor 2N5590.
This is a rather unusual QRP power RF amplifier design, with a wide frequency response; within three dB's from 300KHz to 30MHz. Overall gain is in the region of 16dB and the final output power may be well over four watts.
The wide bandwidth is a result of the construction of the RF transformers, T1 and T2. These are wound on 2-hole ferrite balun cores as commonly found in the old fashioned valve TV sets (e.g. Phillips 4322-020-31520). Twist 2 lengths of 22 SWG enamelled wire together and wind as shown. Connect the end of the "A" winding to the start of the "B" winding. Use this junction as the centre-tap of the transformer.
This PA will deliver 4 watts continuously (with a suitable heatsink), and may be loaded into a short-circuit or open circuit without causing damage. This makes it almost the ideal PA for outdoor/field use. Above is the full circuit diagram of the RFPA and the coil winding pattern. This PA may be used for for SSB, as well as CW (and AM?).
Set RV1 to MINIMUM resistance and apply 12volt power supply with NO DRIVE. Adjust RV1 for about 250mA DC total supply current. This may be be reduced to a much smaller current if lower output powers (reduced drive) is used.
Wednesday, August 31, 2011
This is the RF amplifier for VHF/FM range frequency of 87.5- 108 MHz. The circuit built using power transistor MOSFET BLF245.
The achievement of this 30W RF amplifier was designed to take place on a heatsink microprocessor PC. Equipped with its fans, the advantage of this method of cooling was chosen for the fact it is common and not very expensive. The size of the circuit will adapt quite easily to the type of sink that you have available, nine if possible, because often, those of recovery, the fans have already lived and the price of a new model remains very affordable.
C1,C4 = 47nF50v
C2,C8 = 4,7uF63v
C3,C5 = 22nF50v
C6,C7 = 1nF50v
C9 = 100nF50v
C10,C15 = 2,2nF
C11 = 27pF
C12,C18 = 82pF
C13 = 120pF
C14 = 8,2pF
C16 = 22pF
C17 = 47pF
D1,D2 = ZENER 3,9v
L1 = 2,4uH
L2 = 360nH
L3,L4,L5 = STRIP-LINE
Q1 = BLF245
R1,R3 = 5,6 Ohms
R2,R7 = 1,8Kohms
R4 = 6,8Kohms
R5,R6 = 10Kohms
R8,R9 = 12 Ohms
R10 = 220 Ohms
T1 = TRANSFO COAXIAL
T2 = TRANSFO 2x500nH
Visis this page for detailed explanation and tutorial of the RF amplifier circuit.
Wednesday, August 24, 2011
This is the 40Mhz RF amplifier circuit. The sensitivity of a receiver may be significantly increased if this circuit is inserted between the receiver and the antenna. The amplifier circuit does not use resonant circuits and is suitable for both medium and for the short waves, up to 40 MHz.
The gain of this RF amplifier is 20db and it consumes 7mA electric current, when it is supplied with 12 until 15V dc. The input and the output should be connected with coaxial cable, resistance 75ohm.
|R1 = 75ohm
R2 = 10Kohm
R3-7 = 5.6Kohm
R4-5 = 4.7Kohm
R6 = 820ohm
R8 = 470ohm
R9 = 2.2Kohm
R10 = 68ohm
|C1-3 = 47nF/100V
C2-4 = 10nF/100V
C5-6 = 47nF/100V
Q1-2-3 = AF125
J1-2 = Jack BNC
Thursday, August 18, 2011
This FM power amplifier is build using a bipolar transistor MRF317. Similar to a lots of FM amplifier application, the power transistor is in a C class bias.
All the impedance networks (Input & Output) have been determined by using the Mimp software. A 9 elements low pass filter ensures that we meet at least a 60 dB rejection from the carrier (RF Simulation with RFSIM99). The FM RF amplifier has a 10 dB gain with a 60 to 65% efficiency. The Input VSWR is around 1.4 and there's no problem to reach the maximum power in all the FM band.
100W FM Amplifier Circuit source: radioinitiation.chez-alice.fr
Sunday, August 14, 2011
These circuits may be utilised to amplify RF power signals, from 50MHz to 170MHz, just a couple of component modifications are necessary. The circuit diagram shown are "normalised" for 100MHz and will tune about 80MHz via to 120MHz. Simply scale the components up or down if you want to go down or up in frequency bands. The circuits as shown will give a acquire of about 14dB with an output power of about two Watts (input = 100mW). With an output power of 20 watts the acquire falls off to just 12dB at 100MHz or just 10dB at 170MHz.
L3 can be a massive RF choke, produced utilizing generally 20 turns of 22SWG wire in a ferrite ring. The wire have to be thick enough to carry the PA existing. For low powers a smaller ferrite is extra than sufficient. Do not scale this inductor for other frequencies.
L4 is created working with typically 3 or four turns of 22SWG enamelled wire inside a two ferrite beads side-by-side, as a pair of biniculars. For greater powers you should ideally use a bigger two-hole binocular ferrite core.
L2 is typically 4 turns of "thin" wire on a single ferrite bead for all frequency bands.
L1 and L5 are each close-wound 22SWG enamelled wire on an air-cored 5mm Dia. former. L1 and L5 need to physically be mounted as far away from one another as feasible and in a diverse plane (if one is vertical the other ought to be horizontal).
The 50pf and 75pf preset caps might be any old caps for low power work, but above about 1 watt you ought to choose high-power rated components.
The optional resistor within the emitter will restrict the maximum output power by reducing the gain of the complete amplifier. This resistor should be commonly 12 ohms for low power devices, which include the 2N3866 or 2N4427 devices. For BLW90 or other high-power devices the emitter resistor need to be a total short-circuit. In this event the power supply must also be protected having a fuse. In high-power circuits do not use relay switching or you might burn out relays. The circuit must not draw any important present with no signal. The 18 ohm resistor really should also be reduced for power devices, generally 5R6 for a 20W amplifier.
We have added TR2 to present the 0.7vDC bias inside the form of a basic series regulator. For driving modest transistors like the 2N3866 and 2N4427, TR2 can be a very simple BC547 or a 2N2222. For driving greater power amplifiers you must use a bigger transistor fitted having a heatsink. A 2N3053 or BCY51 device must be fine. Just before switching on the major DC power to the amplifier, set the bias potentiometer to minimum voltage, apply the power and adjust the pot until TR1 draws a bit present. For 500mW to 5 watt devices it is best to set TR1 current to about 5mA to 50mA. With five watt to 25W amplifiers you ought to set the TR1 existing to about 50mA to 200mA. Do not be to mean using the standing DC present as it truly is this that's keeping the FCC of your back by giving you a clean transmission (assuming you have got a license). Now you are able to align the complete Linear PA.
2W VHF linear amplifier circuit source: sm0vpo.com
Wednesday, August 3, 2011
Powered by special transistor designed for RF amplifier: 2SC2092 / MRF475, this RF power amplifier capable to deliver up to 5W signal output. 5W is a high power output for RF power amplifier circuit.
C5 and C8 are disc ceramic. C6 and C7 are tantalum or electrolytic. R1, R2 and R3 are 1/2W carbon composition resistors. Silver-mica capacitors may be substituted for polystyrene (P) types. Impedance transformation ratios are shown above T1 and T2.
Friday, July 29, 2011
This is the circuit diagram of linear FM Booster / RF amplifier based 2N4427 Philips transistor. The RF Amplifier is for boosting small fm transmitters and bugs. It use two Philips 2N4427 and its power is about 1Watt. At the output you can drive any linear with BGY133 or BLY87 and so on. Its power supply has to give 500mA current at 12 Volts. More voltage can boost the distance but the transistors will be burned much earlier than usual.! In any case do not exceed the 15Volts. The Amp offers 15 dB in the area of 80Mhz to 110 Mhz. L4, L5, and L6 are 5mm diameter air coils, 8 turns, with wire 1mm wire diameter. This is an easy project, but will give you great results.
Sunday, July 24, 2011
This is a 5W -150MHz RF amplifier circuit. It applies the MRF123 TMOSFET. The MRF123 is a very high gain FET which potentially unstable at both VHF and UHF frequencies, so the 68 Ohm input loading resistor has been used to enhance the stability. This RF amplifier has a gain of 14 dB and a drain effeciency of 55%.
Tuesday, July 19, 2011
This is a low cost, antenna-mounted, this UHF TV pre-amplifier circuit can add more than 25db of gain. The first stage of the pre-amplifier is biased from optimum gain. L1, L2 strip line equivalent with Lambda/8 of PC board. The circuit uses BFQ85 as active commponent to amplify the UHF signal, the BFR90 can be used as component replacement for BFQ85.
Monday, July 11, 2011
The above schematic diagram is the wide band RF amplifier circuit which is suitable for the frequencies between 10MHz and 500MHz.
This wide band amplifiers can be used in RF measuring equipment, communication receivers, and tons of other devices related to high frequency (radio frequency). The circuit described here uses a state of the art transistor to get maximum performance at high frequencies. It can be used as a low noise pre-amplifier due to its low noise characteristics.
RF Amplifier specifications:
- Supply voltage : +12V
- Current : 10mA
- IP2 : 110dBuV
- IP3 : 105dBuV
- Input / output impedance : 50 Ohm
- Frequency range : 10MHz – 500MHz
- Noise figure : 3.5dB typical
Documentation about this 10Mhz-500MHz RF Amplifier can be download from this link
Thursday, July 7, 2011
The 60 Watt linear rf amplifier is easy all solid state circuit applying power mosfet IRF840. The IRF series of power transistors are provided in a number of voltage and power ratings. A single IRF840 can carry out maximum power output of 125 watts. Because these transistors are applied in inverters and smps, they're simply presented for about Rs: 20/-.
The IRF linear amplifier could be connected to the out put of well-known VWN-QRP to obtain an output of 60 Watts. The circuit draws 700 ma at 60 Volt Vcc. Great heat sink is actually a ought to for the power transistor.
Alignment of the circuit is quite effortless. Connect a dummy load to the out put of the circuit. It is possible to use some modest bulb like 24V 6Watts as the dummy load. I've even utilized 230V 60Watts bulb as dummy load with my IRF840 power amplifier working at 120Volts. Adjust the 10K preset to obtain about 100 ma Drain current. I applied gate voltage of 0.8V with my linear amplifier. A heigh gate voltage can make the power transistor get distroyed by self oscillation. So gate voltage ought to be below 2V and fixing at 1V is going to be secure.
Bifalar transformaer T1 is wound with 8 turns 26SWG on 1.4 x 1 balun core. The coil on the drain of IRF is 3 turns 20 SWG wound on 4 number of T13.9 torroids (two torroids are stacked to form a balun core). The RFC at the Vcc line is 20 Turns 20 SWG wound on T20 torroid.
60W Linear RF Amplifier circuit source:
Sunday, July 3, 2011
- Depend on this amplifier to boost your Cable/UHF/VHF/FM signal after splitting
- (1) 75 ohm "F" Connector (RG59 or RG6) Input, 2 Outputs - 24db Signal Amplifier
- Nickel-plated Connectors for Reliable Contact
- Die Cast Body - Environmentally Friendly Lead-free Construction
- Note: Not for Use with Cable Modems or Digital Cable Boxes
Buy the Philips RF Amplifier / Splitter SWS2082W Amazon.Com
Wednesday, June 29, 2011
Saturday, June 25, 2011
10dB VHF/UHF/FM Signal Amplifier Features:
- Increases VHF/UHF/FM signals by 10dB
- Compensates for signal loss/weak signal that occurs during long cable runs or multiple TV/VCR connections
- For use with both RG6 and RG59 coaxial cables
10dB VHF/UHF/FM Signal Amplifier Review:
We recently cut our ties with DirecTV and just went with more than the air digital signal. The RCA outside antenna worked great, but sometimes the picture pixelated. Getting study critiques and experiences of other people, I bought this signal amplifier and was blown away by the difference this little device made. We had extremely good HD quality, but this created it even better AND we found 4 much more stations that we weren't obtaining prior to utilizing this.
Better picture, no pixelation and much more channels! Great Deal!
Buy 10dB VHF/UHF/FM Signal Amplifier from Amazon.Com
Wednesday, June 22, 2011
C1,C3 = 75-380 pF mica trimmer, ARCO 465
C4-C8 = .01 uF 1 kV disc ceramic
C9,C10 = .1 uF 500V disc ceramic
L1 = 6 uH. 25t #24 ga.enam. 0.5" dia.
L2 = 210 nH. 4t #8 ga. .75" id, 1" long
L4 = 2t #20 PTFE on .5" ferrite bead m=850
Q1 = APT ARF448A
R1 = 25W 5W non-inductive
T1 = Pri: 4t #20 PTFE, Sec: 1t brass tube on 2 hole balun bead. Fair-Rite #2843010302 m=850
High voltage MOSFETs are now available that combine the best practices from the RF world with the economy of the switchmode devices and packaging. They are available in mirror image pairs and the heat spreader of the plastic TO-247 package is connected to the source.
Download the aplication note for this circuit 500W 27Mhz RF Amplifier HERE
Sunday, June 19, 2011
The circuit uses four PL519 Television line output valves inside a very simple circuit that will deliver above 450 watts at 3.5 MHz (350 watts at 30 MHz). PL519 (40KG6A) is a far more robust substitute for the earlier PL509 (40KG6) tube. Each valves will do the job properly in this circuit. The input drive power is about 50 - 100 watts so it really is working with most amateur radio HF transmitters. Not shown in the circuit will be the cooling fan that is needed to force air across the valves to cool them. In operation the 1K0 pot is adjusted to set the complete valve anode electric current to close to 50mA to 70 mA.
Detailed explanation : go to this page
Tuesday, June 14, 2011
The component part list for this RF amplifier circuit, you can check inside the 50MHz 300W MOSFET Amplifier Circuit document.
- Frequency range: 50 to 51 MHz
- Input VSWR: < 1.5:1
- Gain: >13 dB
- Output Power: 300 W PEP or CW
- Efficiency: > 50%
- IMD3: < -25 dB below PEP
Download 50MHz / 300W MOSFET Amplifier Circuit complete document HERE
Thursday, June 9, 2011
Simplicity and repeatibility are featured in this 1 Watt S-band amplifier circuit. The circuit used a common-base power transistor MRF2001, a class C amplifier. This RF amplifier delivers about 1 Watt power output with 8-dB minimum gain at 24V voltage supply. The frequency can be tuned from 2.25GHz to 2.35GHz
Complete explanation and how to build this 1 Watt RF Amplifier, go to this page.
Sunday, June 5, 2011
Wednesday, June 1, 2011
The RF amplifier is designed based on the M/A-Com LF2810A MOSFET. The transistor is basically a 10 watt, 28 volt part, but supplies sufficient gain for this application at 12 VDC. The amplifier delivers higher than 40% of efficiency in the desired output capability. Trimmer capacitors are applied for input and output matching. Output power is altered by a trimmer potensiometer (trimpot) which sets the gate bias voltage.
RF Amplifier circuit source: http://www.ham-radio.com/wb6zsu/components/exciter/exciter_mods.html
Saturday, May 28, 2011
This RF Amplifier document is focused on exploiting the RF design capabilities of HFA3046/3096/3127/3128 transistor arrays.
Detailed design procedures, using these transistor arrays, for a matched (800MHz to 2500MHz) high-gain low-noise amplifier and a 10MHz to 600MHz wideband feedback amplifier are described.
Download the complete application document of this RF amplifier circuit:
» Download Link
R1, R2, R3, R4 = 100
R5 = 10k
C1 = 220uF
C2, C3, C4, C5, C6, C7 = 100nF
C8, C9 = 1nF
C10, C11, C12 = 22pF
C13, C14, C15, C16 = 15pF
C17, C18 = 10pF C
19, C20 =(Variable capacitor 5-25pF)
L1, L2 = 10uH
L3 = 45nH 2 turns diam 5mm (wire = 0.8mm)
L4 = 27uH (Can be 10uH-100uH)
L5 = > 500nH 10-15 turns diam 6.5mm (wire = 0.8mm)
L6, L7 = 100nH 3 turns diam 6.5mm (wire = 0.8mm)
Q1 = BFG193
Q2 = MRF313, 2N3866, 2N4427
Complete explanation about this RF amplifier circuit, go to this page
Coaxial cable length : K x Lambda / 4, where K = 0.66 for 50 ohm cable and K = 0.8 for 75 ohm cable.
L1 = L6 = 2 turns / 1.5mm / 14mm
L2 = L7 = 8turns/0.8mm/4mm/ferite or HF
L3 = L8 = 4 turns / 2mm / 14mm / gap 1mm
L4 = L9 = 20turns/0.3mm / 3mm / ferite
L5 = L10 = 1 turn / 2mm / 15mm
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Motorola Signal Booster Bi-Directional RF Amplifier Features:
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- Low noise addition of only 3 dB
- Superb gold patented connector design
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- Quick, easy installation
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