Friday, July 29, 2011

1W FM Booster based 2N4427

electronic diagram

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

5W / 150MHz RF Amplifier Circuit

5W / 150Mhz RF Amplifier Circuit diagram

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

UHF-TV Preamplifier circuit

UHF-TV Preamplifier circuit diagram

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

10Mhz-500MHz RF Amplifier

10Mhz-500MHz RF Amplifier circuit diagram

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

60W Linear RF Amplifier Circuit

electronic circuit diagram

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

Philips RF Amplifier / Splitter SWS2082W

This is Philips RF Amplifier and splitter, of course this device has capability to split the signal received and boost those splitted signal to get the stronger signal amplitude.
Philips RF Amplifier / Splitter SWS2082W

Product Features
  • 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