Description.
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.
Notes.
- 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.
42 Comments
what is equivalent transistor for 2SC4308 and 2SC1324
What I change to use this for upto 600mhz
What I change to use this for upto 1000mhz
i need a circuit of
frequency 47-862MH
level 45-90dBuV(75ohm)
band 8MHz
symbol rate 6.900Maud
imudence 75ohm
is it working?
Ist useful
i need set top box circuit diagram
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.
from above notes I cant understand the operation of this circuit plz explain briefly
what is, “IN” “OUT”?
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?
How will i applied it on my cable TV decoder.and will it work if i built this at home
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
By
Dhamodharan.S
Since Comcast and Charter are at 1Gigahertz,
how about a circuit to amplify at that frequency?
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
please send me a Circuit diagram of power saver if you have….thanks
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?
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.
haaaaaaaaa what a wonderful bullshit. 150MHz for cable tv !! what a big funny lol . do u hav any cable amplifier upto 850MHz ….
Hi Mohin you can use for Low Mid and High Band cable channels not beyond that. refer the following table.
http://www.tvtower.com/Commercial%20Television%20Frequencies.html
Can we use it where cable have 200 channels ??
But can it be use for 200 channels ??
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?
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.
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
What will be the cost for the components.I have really bad cable tv connection.
Where would i found 2sc1324,bfr36,bfw16,2sc1068 or 2sc 2570 in hyd
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.
Where would i found these transisters
pls tell me the place and shop name
sir, I want a FM BOOSTER circuit,with out trimmers because these are very difficult to get from shopes.thankyou.
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.
Sir,
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
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.
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 ?
hi Muhammad Ibraheem no. this circuit is not suitable.
HI,
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
Hi Digonto It requires around 16mA.
How much current do I need for this circuit ?
Please reply ………..
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 ?
-Thanks
Hi the most popular 2SC2570 UHF low noise transistor used in VCR RF amplifier can be used successfully.
Zaeem Ahmed,
Transistor 2SC1324 subtitute BFR 36, BFW 16, 2SC1068
Thanks
Sumon
sir please send me the subtitute for transistor 2SC1324.
THANK YOU