Hi,
First question is why analog cable do not radiates in the air even if I connected a sort wire (as antenna) to the core wire of cable TV? Yes it radiates few inches poorly or TV receives poor signal if I did so. Does it mean the signal of cable TV is so low to transmit in the air?

Main question is, to transmit cable TV in the air such devices available : http://www.aitech.com/products/wirelesscabletv.htm But I am not getting simple version of toy cable TV transmitter 'circuit' around internet easily. There are just TV modulator (transmitter) available.

The highest channel of my cable TV has 855MHz so I think I could experiment with few of S9018 (1.1GHz) transistors if I could find guidance circuit.

 

Does it mean the signal of cable TV is so low to transmit in the air?

I'm no expert, but yes, the signal is far too small.

Main question is, to transmit cable TV in the air such devices available : http://www.aitech.com/products/wirelesscabletv.htm But I am not getting simple version of toy cable TV transmitter 'circuit' around internet easily. There are just TV modulator (transmitter) available.

I don't understand the question. What's wrong with the commercial products? What are you looking for but not finding?

 

You probably can't find simple circuits because broadcasting the whole wide-bandwidth cable TV signal is likely illegal.

 

Edit post #3 - completely illegal, even at 29,000 feet.

ak

 

Probably it's not illegal to transmit around a room.

 

Probably it's not illegal to transmit around a room.

But how do you confine it to the room, unless it's a screen-room?

 

In my FM toy transmitter experience, a general purpose BJT OSC with 3V transmits just around room without antenna connected.

I have an experience of jamming TV of my home too when I turned ON my DIY and poor man's regenarative FM receiver. I did't used that one any more.

 

The signal from your normal cable TV cable is very low.

http://www.terapeak.com/worth/cable...l-headend-audio-video-modulator/231645546942/
Get one of these a stick an antenna on the output - Totally illegal of course, but you aren't radiating enough power for anyone to care.

Any "simple circuit" to transmit video is going to perform horribly, it's not a trivial affair to create a proper RF video signal.

 

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http://www.terapeak.com/worth/cable...l-headend-audio-video-modulator/231645546942/
Get one of these a stick an antenna on the output - Totally illegal of course, but you aren't radiating enough power for anyone to care.
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That is a modulator.
He just wants an amplifier for the cable signal, which is already modulated with the video.

 

That is a modulator.
He just wants an amplifier for the cable signal, which is already modulated with the video.

My bad- misread the post.
How about a "distribution amp"?

 

Thank you sensacell, but for this moment I do not want to use professional devices. I just want to experiment and see. So I want to play with DIY circuits.

 

Thank you sensacell, but for this moment I do not want to use professional devices. I just want to experiment and see. So I want to play with DIY circuits.

Unless you've had some experience with wide-band, high-frequency circuits, good luck with that.

 

I found exactly as I wish but chip seems unique. I just have 1.1GHz 20mA transistors (S9018) to experiment in the case. http://www.next.gr/video/UPC1651-pr...video-transmitter-circuit-diagram-l59856.html I am just an hobbyist and I am weak in knowledge. But do not worry about me, I think I am very aware in the aspect of rules of the country. Because I work under the government (school teacher) so.