TV reception problem

[Ravi]

Hi Friends

My neighbors house is situated more than 50 meters apart from my home. When I play a DVD or when my children play a TV game, this could be seen on their TV as well. Similarly, when they play a DVD we can see it on our TV. (UHF channel). There is no electrical connection between the houses other than the mains power line. I tryed moving my antenna's location but not results. My worry is that when they play a unsolicited DVD my children can watch it. Could anyone explain the whole phenomena and suggest a solution? I do not mind building a ckt to interrupt their transmissions.( I know this is unethical). Appreciate very much if you send me a suitable ckt.

Regards

 

[Sebi]

Very interesting problem... maybe used wireless system between TV and DVD? Or simple cable, not coax? In Your side possible build a notch filter for used UHF-channel.

 

[Klaus]

Ravi, what you describe sounds quite unbelievable to me. TV sets do not, as a norm, re transmit signals.
Before you try building fancy circuits thry this, assuming your neighbour will cooperate: Since you do not need an antenna for playing DVD's, disconnect it from the set when playing these or TV games. Ask your neighbour to do the same when he is playing DVD's.
If that fixes it, check your antenna wiring carefully or have the set checked for problems.
If you still get interferance then I can only assume that the little green men have tampered with your TV set .
Klaus

 

[Ravi]

Dear Klaus,

I also can not believe this but this happens in the real world. I'm experiencing this problem for a quite some time. I know TV sets are not re-transmitting signals. I think DVD players are doing so. The image in the screen is not very clear but you can see the pictures and hear the sound. I was wondering whether the signal is being transmitted throught the AC line, because both the houses are supplied with the same 3 phase line but tapped at differnet phases.

Antenna is not connected to the TV whilst paying the DVD but left aside near the player. Neighbors house is at a little high elevation. (if they see from their windows, they can directly see my roof). With their permision once, I went to their's & watched their TV whilst my player was 'ON'. Same thing!!. But this is not happening when I play my video player.

 

[Klaus]

Interesting Ravi, so the interference cannot travel via the antenna since it is not connected in your house. I would not think that DVD players put out a strong enough signal to travel 50 metres through the air and be picked up via another antenna.
If it goes via the AC lines as you say there is a simple cure, fit ferrite toroid cores round the cable, like the ones you see on the cables of computers and switching power supplies.
Another thing you can try is to fit a more directional antenna to your TV set, as long as the station transmitter is not in exactly the same direction as your neighbour :? .
You could also ask your local antenna installer to do some field strength measurements with his instrument tuned to the DVD output signal, just to see how strong a signal comes out of these.
Good luck
Klaus

 

[spuffock]

a couple of suggestions. If the dvd is connected to the antenna socket of the tv, check the connection to the cable outer, or try a new cable. A faulty cable may act as an antenna.
This is very unlikely, but if the dvd has a socket '' RF out'' that is not used, try fashioning a screening cap from a piece of aluminium foil and fitting it tightly over the socket. Good luck!

 

[adrianospiteri]

Interesting

Well this is quite an interesting post. Surely enough this could nto happen if the neighbour connects the DVD to TV using composite. There are scart to composite adapters that can be used to connect composite to the Auxiliary of the set.

The problem of transmission can only be caused when DVD is connected to the TV by a coaxial wire. Here, espescially with a wrong coax impedance the signal harmonics spread long enough to pass through wood and sometimes small bricks. This case is quite interesting sinmce the distance mentioned is too long ! But anyway, harmonics are a hella wonder !

You ask him to use composite and the problem is solved.

 

[NEXUS1]

I have seen this before.

I have seen this before where a customer had a faulty antenna/signal amplifier. The Amplifier would transmit the signals present on the TV side (output) back to the antenna (input) side thus naking it a small tv transmitter.

 

[Slashdot]

Another simple solution would be to use the Audio and Video jacks to supply the signal to the TV , this would take RF right out of the loop entirely , provided the TV has A/V inputs

 

[Ravi]

Thank you very much guys. I will try your suggestions & keep you informed of the developments.

 

[varun]

RAVI your DVD system

TV set doesn't re transmit the signals.Its due to player and the signals produced by the player spreads in the space which are received by the TV set of your neighbour.You can stop it by proper grounding of the signals produced by the DVD player.try to do so by shielding the player and it may solve the problem. ask the same to your neighbour when the problem gets rectified,i hope it'll work:arrow:

 

[varun]

RAVI your DVD system

you can replace your RF cable by AV cable and that will also help in sorting out the problem as the radiated signals are due to RF output of the DVD player.

 

[varun]

RAVI your DVD system

you can replace your RF cable by AV cable and that will also help in sorting out the problem as the radiated signals are due to RF output of the DVD player.