FM Amplifier | Electronic Project Circuits

Posts Tagged ‘FM amplifier’

1W Linear FM Booster by 2N4427

That RF Amplifier is for boosting small fm transmiters 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.An easy project, with great results.

Be the first to comment - What do you think? Posted by admin - November 4, 2008 at 7:22 am

Categories: Power Amplifier, RF-Radio Frequency Tags: FM amplifier, RF amplifier

100W FM AMPLIFIER by MRF317

This Power amplifier is equiped with a bipolar transistor,the famous MRF317

As 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 software: Mimp.EXE.

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 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 max power in all the FM band..

Read More Source:http://radioinitiation.chez-alice.fr/english/ampli100W/ampli100w.html
Thank you.

Be the first to comment - What do you think? Posted by admin - February 8, 2008 at 6:13 pm

Categories: RF-Radio Frequency Tags: FM amplifier, RF amplifier

RF power amplifier 80W by C2782

This is a pretty conventional design, using bipolar transistors in a tuned class C circuit. Thanks to the use of two stages, the amplifier can be driven to full power with less than 1 watt driving power, so that a large gain margin results in this transmitter.

Bipolar VHF power transistors have a severe affinity for low frequency self-oscillation. To obtain stability in this amplifier, I employed several techniques, such as placing the resonances of base and collector chokes far apart, damping the chokes with resistors, using RC combinations for absorption of unwanted frequencies, using feedtrough capacitors for bypassing on the board, etc. It took some tweaking, but the amplifier ended up unconditionally stable.

The impedance matching network between the two transistors calls for such a low inductance, that it would be impractical to make it with actual wire. So I used a micro stripline etched on the PCB. Also, the power and SWR sensor at the output was made with micro striplines.

Read More Source:http://ludens.cl/Electron/fmtx/fmtx.html
Thank you.