Linear FM 50Watt with BLY90 50

Linear FM 50Watt with BLY90 50W FM FM power amplifier circuit

A amplifier of force RF for the FM, is always essenTIal for the amateur that wants it strengthens some small transmitter, that likely already it has manufactured or has been supplied ready. The present circuit can give 50-60W RF force of expense, with control smaller than 15-20W in the region of frequencies of FM, that is to say in the 88-108MHZ. Transistor that we selected for this manufacture is the BLY90, that has gain 5dB. DescripTIon

image 1

As it appears in the analyTIc drawing (image 1) the amplifier is manufactured with transistor TR1, type BLY90 of Philips. The transistor this is specifically drawn for operaTIon in frequencies up to 175MHZ, with very good results of linearity and record of force. In his technical 'characteristics they are included the tendency of operation in the 12V the current of collector in the gain expense in the 5dB (measured in order C) and force of entry in the 16W. Variable capacitors C1, C2, with inductor L1, constitute the circuit of co-ordination, that adapts the exit of our transmitter in amplifier RF. This circuit has been calculated lead, so that it covers all band the FM with the biggest possible output. Inductor RFC1 polarized the transistor, so as to it works in order C, that is to say with the biggest output. Inductor L2 in the collector of TR1, constitutes the charge of amplifier, while RFC2 prevents the RF signals leak in the line of catering. Capacitor C2 and resistance R1, pr otect the circuit from auto polarization. The coordinated circuit of expense that is constituted by inductor L2 and variable capacitors C3, C4, adapts the exit of amplifier RF with the next stage, which can be constituted from some amplifier RF of high force (> 300W ) or a aerial. This circuit can be supplied with 12V fe from the battery of one automotive, so that it renders the system emitter portable. Thus, easily it can be moved in points with bigger altitude, in order that from there are achieved radio transmissions, something that was also got used in the past by romantic amateur of radio band.

The manufacture

The manufacture of amplifier, is very simple and easy, it is enough to look the images 3 and 2 that portray pcb the amplifier and the placement of materials in this. Puncture the point pcb, that pass the nutshell of TR1. Sticks the capacitors, variable, the resistance, RF tsok and the inductors. Finally you stick TR1, being careful not overheating at the welding and bend the pins his. Clean finally pcb from the residues of iron. Make a very careful control for by any chance errors, omissions , short-circuits, chills you stick also anything other that could you make think that will not work the amplifier.

image 2

If all they are it includes, you connect the exit of your transmitter (15-20W) in input the amplifier. The exit of amplifier him you will connect in some charge (dummy load) or in the aerial, through bridge stagnant waves. Supply with tendency 11-15V your amplifier (power supply it should gives current 4-5A). Regulate the 4 variable C1-C4, until you take the biggest force of expense. The amplifier is ready.


C1-C4 = 10-80pF L1 = 1 coils of diameter of 10mms, 1mm
C5 = 10nF L2 = 7 coils of diameter of 10mms, 0,8mms
C6 = 1000pF L3 = 3 coils of diameter of 10mms, 1mm
C7 = 100nF TR1 = BLY90
C8 = 2200mF / 35V

Wifi Magnetic Antenna DESCRIPTION:
Main Features

Crossing the Obstacles
This WIFI extension antenna can be widely used in a wireless video surveillance system to strengthen the connection between the IP camera and the NVR. It is used when NVR can't receive strong signal from camera due to the far distance or physical obstacles.
· For trough wall/ floor transmission
· Reduce the distance between cameras and NVR
· Built solid connection between the cameras and NVR in your wireless CCTV system

Stick it To Any Surface
This 3m/9.8ft WIFI extension antenna is built with magnetic base and equipped with a 3M adhesive tape. You can stick it to any metal surface or just attach it to walls or ceilings using the included 3M adhesive tape.

Durable Quality & Easy to Use
Built with premium material this Wifi Antenna is durable to use. And the installation process is quite a breeze. Connect it to your WIIF camera and stick it to any surveillance and all is done.

WIFI Magnetic Antenna

  • It is widely use in wireless CCTV cameras to strengthen the connection to the NVR when the distance is two far or there're physical obstacles between them like walls or ceilings
  • Easy mounting: Designed with magnetic base and equipped with 3M adhesive tape, it allows you to stick it to any metal surface and mount it on any surface (wall, ceiling, glass etc.) with the 3M tape
  • 7dBi high gain cable with copper core. And the antenna is removable from the magnetic base. Supper easy to use and install
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Wifi Magnetic Antenna

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Shenzhen Yetnorson Technology Co., Ltd. ,