Cable TV amplifier

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.

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44 thoughts on “Cable TV amplifier

    • basil

      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.

  1. djjohnnyb

    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?

  2. S.Dhamodharan

    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


  3. maaz ranjha

    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

  4. Aye Su Mon

    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?

  5. Aye Su Mon

    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.

  6. Silva

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

  7. Jitendra

    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?

  8. Seetharaman

    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.

  9. Seetharaman

    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.

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  11. nidesh

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

  12. seetharaman

    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.

  13. vmschary

    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

  14. seetharaman

    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.

  15. Digonto

    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 ?

  16. Muhammad Ibraheem

    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

  17. Digonto

    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 ?


  18. seetharaman

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


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