TV antenna booster

admin July 22, 2010 25 Comments

Description.

The circuit shown here is of a TV antenna booster based on the transistor BF180. The circuit operates in the UHF band and has a gain of 15dB. Capacitors C2,C3 C4 ,C5 and inductors L3, L4 forms a UHF band pass filter. The input signal is fed to the emitter of Q1 through this filter. Resistor R2 and R3 biases the transistor Q1 which is wired in the common base configuration.

Circuit diagram.

Notes.

  • Assemble the circuit on a good quality PCB.
  • For better performance, enclose the circuit in a metal box.
  • The circuit can be powered from 12V DC.
Comments
  • mnasim31
    March 26, 2015

    Seetharaman jee, can I use this circuit as add-on to my UHF tv transmitter circuit in between the circuit and the antenna? Thanks

  • okpala michael
    August 24, 2014

    sir can i use BC547 to replace the transistor. tanx for the ckt

  • martin
    June 26, 2014

    where will i feed my cathode (-) from 12vdc to my circuit board

    • Seetharaman
      June 27, 2014

      Negative to common shown as ground.

  • Faruk
    April 21, 2014

    Pls i want to know what is wrong wit my antenna the signal strength is very low

    • Seetharaman
      April 22, 2014

      Check for corrosion in the connecting leads, Dipole edge connections at the clamp end. directors and reflector also should be clean at the clamp end. The dipole should not touch each other at the wire connecting end. You check the continuity of the antenna wire at the receiver end it should be 15 to 50 ohms depends on the length of the cable used from antenna. Do not coil the excess length of the cable anywhere. cut the excess length use only the required length of cable. Check also the direction of the antenna

  • January 16, 2014

    tv antenna amplifyer circuit

  • moses
    April 8, 2013

    Pls send right up on fire alarm using thermistor

  • alvin
    February 13, 2013

    please wht is the function of L1 and L2 and C7, C6, C8, C1, R1. I have to defend this in my project please.

  • priatna
    May 16, 2012

    saya membutuhkan antena yng cocok untuk di daerah pegunungan yng sinyalnya sangat lemah sekali. tolong ksik petujuk/ jawabannya. thankyou

  • Kasun Chaga
    December 31, 2011

    Could you please send me a PCB layout of this TV booster circuit. Thank you very much.

  • April 8, 2011

    thanks alot. Ill makd one

  • Seetharaman
    March 30, 2011

    In winding inductors for RF designs, this measuring circuit allows the designer to know exactly when the desired inductance has been achieved. As an example, the number of turns for a single layer air core inductor is given by

    N =[ √l X (9a + 10b) ]/ a²

    where

    l = inductance in microhenries,

    a = coil radius in inches,

    b = coil length in inches,

    N = number of turns.

    • Pete McQuade
      May 1, 2013

      How do you know what guage wire to use with this formula?

  • March 29, 2011

    Hi whow can i make those inducters as they are not aveilable in market?

  • March 25, 2011

    woo. It works well but how can i increase gain?

  • Seetharaman
    March 24, 2011

    Hi use cable TV amplifier appeared earlier on this site

  • hi
    March 22, 2011

    Hi
    for VHF?
    PLEASE HELP ME

  • Seetharaman
    January 2, 2011

    Hi Howard use a low pass filter for DC and Hi Pass filter for the RF. (just a capacitor to block DC and a choke to block RF.

  • howard
    January 2, 2011

    I’d like to build manhatten-style (point-point, directly on a copper-clad board), mount it on the back of a UHF bow-tie antenna, and powered from a wall-wart at ground level. How can I separate the DC power from the RF if I use only the RG-6 feeder cable for the interface?

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  • seetharaman
    July 26, 2010

    Hi Manir you can use 2N918 BF594 BF597 BF595 BF197 BF195 BF194 BF195 BF 173 BF176 any high frequency transistor can be tried

  • Manir
    July 25, 2010

    Hi,

    BF180 is not available in the stores around Toronto, 2SC2570 is not either.

    What are the substitutes of BF180?

    Thanks.

    Manir

  • seetharaman
    July 23, 2010

    Hi Roger i have not yet tried with BF180 but i tried with 2SC2570 really good performance in UHF band noisey signal will improve and the grainy picture will get improved, audio mush also will come down.( you cannot use where signal strength is quite high

  • roger
    July 22, 2010

    is this really good?

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