Cable TV amplifier

john August 17, 2009 47 Comments

This is a very simple cable TV amplifier using two transistors. This amplifier circuit is most suitable for cable TV systems using 75 Ohm coaxial cables and works fine up to 150MHz. Transistor T1 performs the job of amplification. Up to 20dB gain can be expected from the circuit.T2 is wired as an emitter follower to increase current gain.

Circuit diagram.



  • The circuit can be assembled on a Vero board.
  • Use 12V DC for powering the circuit.
  • Type no of the transistors are not very critical.
  • Any medium power NPN RF transistors can be used in place of T1 and T2.
  • This is just an elementary circuit. Do not compare it with high quality Cable TV amplifiers available in the market.
  • dhanasekar
    August 18, 2015

    what is equivalent transistor for 2SC4308 and 2SC1324

  • justin
    May 18, 2015

    What I change to use this for upto 600mhz

  • justin
    May 17, 2015

    What I change to use this for upto 1000mhz

  • vishnu
    February 1, 2015

    i need a circuit of
    frequency 47-862MH
    level 45-90dBuV(75ohm)
    band 8MHz
    symbol rate 6.900Maud
    imudence 75ohm

  • Sourav Saha
    January 27, 2015

    is it working?

  • October 29, 2014

    Ist useful

  • kumar
    November 22, 2013

    i need set top box circuit diagram

    • February 12, 2014

      pls if you have a soft copy of Semi-conductor Data book, pls send it to me

      am in great need to find alternative component to complete my project.

  • muthulakshmi
    August 19, 2013

    from above notes I cant understand the operation of this circuit plz explain briefly

  • joseph Thambi
    July 15, 2013

    what is, “IN” “OUT”?

  • July 13, 2013

    The amplifier works, but it runs at about 600MHz transmission. The switching transistor 2SC2570 used. Closed metal box, with a stable 12V power supply. F connector. What could be the problem?

  • abimbola
    March 24, 2013

    How will i applied it on my cable TV decoder.and will it work if i built this at home

  • S.Dhamodharan
    November 16, 2012

    Respected Sir,

    I have finished UG-BSc electronics and communication system on Apr 2012. Now I am searching Job about electronics relationship.If any vacancy
    in there.Please kindly inform me.

    Thanking You


  • September 16, 2012

    Since Comcast and Charter are at 1Gigahertz,
    how about a circuit to amplify at that frequency?

  • maaz ranjha
    February 13, 2012

    hi i am a electricion and try to do the small small projects of domestic level so it is a so better circuit of cable tv circuit.thanks

  • poller
    July 10, 2011

    please send me a Circuit diagram of power saver if you have….thanks

  • Aye Su Mon
    June 5, 2011

    Hi i m electrical student.I took this circuit for my project.I want to know how to convert this circuit to simplified h-parameter equivalent circuit with complete calculation.And how the resistors are connected?Are they in series or parallel?

  • Aye Su Mon
    June 5, 2011

    Hi!I am Aye Su Mon.I am an electrical student.Now I have to do Analog Electronic circuit project.May I know how to simply this circuit using calculation?How do the two transistors work and how about the relationship of the resistors?Thank you.

  • Silva
    May 10, 2011

    haaaaaaaaa what a wonderful bullshit. 150MHz for cable tv !! what a big funny lol . do u hav any cable amplifier upto 850MHz ….

  • Seetharaman
    April 14, 2011

    Hi Mohin you can use for Low Mid and High Band cable channels not beyond that. refer the following table.

  • Mohin
    April 13, 2011

    Can we use it where cable have 200 channels ??

  • Neon
    April 13, 2011

    But can it be use for 200 channels ??

  • Jitendra
    March 12, 2011

    Can it be used for UHF band(300 MHz and 3 GHz) apart from VL and VHf band? If not, then what changes should be made to do this?

  • Seetharaman
    March 9, 2011

    Hi VIC it can operate at that frequency also.
    Hi Deepak within INR 100 you can can assemble it.
    Hi Rajesh you can try with RS Components SD road Hyd – 3.
    also Bank street Hyd – 95. 2SC2570 is a very popular UHF transistor.

  • March 8, 2011

    Does this work on a VHF Radio system. i am going to use it on 157.4250 Mhz as a pre amp to a repeater

  • Deepak
    January 28, 2011

    What will be the cost for the components.I have really bad cable tv connection.

  • Rajesh
    December 20, 2010

    Where would i found 2sc1324,bfr36,bfw16,2sc1068 or 2sc 2570 in hyd

  • Seetharaman
    December 15, 2010

    Hi Rajesh 2SC2570 is the most popular Low Noise UHF transistor available in all electronic spare parts shop in India. If you are at Bombay try Visha Electronics or Vega Kits or any shop at Lamington Road.

  • Rajesh
    December 15, 2010

    Where would i found these transisters

    pls tell me the place and shop name

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  • nidesh
    October 7, 2010

    sir, I want a FM BOOSTER circuit,with out trimmers because these are very difficult to get from shopes.thankyou.

  • seetharaman
    June 11, 2010

    Hi Chary try using 2SC2570 for both the transistors. You can find the difference in the noisey channels both in audio and video or atleast in audio (the frying noise with audio will get reduced). Finally you may try a 6 turns close wound air core coil of 6mm dia with 18 SWG super enameled copper wire, between C2, R5 junction and ground.

  • vmschary
    June 10, 2010

    I cant getting any changes in quality of picture, and I am using Transformer with rectifier and capacitor for providing 12v supply. please solve my problem,
    Thank you

  • seetharaman
    May 4, 2010

    Hi Dignto no need, the same transformer can be used. the circuit will consume only 16mA. (it is just peanuts for the transformer). So you can comfortably use your tansformer with rectifier smoothing capacitors and regulator.

  • May 4, 2010

    Oh no! Where will I get so lower Current transformer . I have a 12V and 600mA transformer only . Can I use this transformer in this circuit ?

  • seetharaman
    May 4, 2010

    hi Muhammad Ibraheem no. this circuit is not suitable.

  • May 3, 2010

    I wanted to ask whelther this circuit would be ideal to amplify wifi signals around 2.4 to 2.5 Ghz.I was working on a project in which i have to spread my wifi signals in 10km radius,i can use this circuit in series to amplify signal many many times,ill use atleast 15 of these circuits in series

  • seetharaman
    May 3, 2010

    Hi Digonto It requires around 16mA.

  • Digonto
    May 3, 2010

    How much current do I need for this circuit ?

    Please reply ………..

  • April 30, 2010

    12V and What Amp.? Transformer will I use ? Will It work in more than 100 Channels TV Cable ? And Is it For a Single TV ?

    Actually, I have a Television and Computer TV Card in my home . When My dad watch TV, then my TV Card display poor quality Picture . Otherwise it is good . May be it is happennig for less line gain when running two sets (Television+TV Card) .

    If I use this Amplifier for my TV Card then will it solve my problem ?


  • seetharaman
    April 15, 2010

    Hi the most popular 2SC2570 UHF low noise transistor used in VCR RF amplifier can be used successfully.

  • Md. Sumon Biswas
    April 14, 2010

    Zaeem Ahmed,

    Transistor 2SC1324 subtitute BFR 36, BFW 16, 2SC1068



  • April 9, 2010

    sir please send me the subtitute for transistor 2SC1324.

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