Weirdest noise ever

[Jezreel]

Hey all: I recently bought a very cheap bt878 card and Im having a very weird problem on some channels, especifically the ones above 50 im getting a very weird noise(see attached file) I was wondering if any of you had ever encountered this and knew what it might be. Thanks in advance.
http://pwp.etb.net.co/Hernandob/capture.jpg

[rfmmars]

I am sure you are talking cable TV. As your channels go higher so does the loss in the cable and the noise floor in the line distrubution ampilfiers feeding you and more noise.

Solution maybe a 10db line amp from Radio Shack

Off Air has the same problem but a low noise UHF amplifier coupled to a hi-gain yagi antenna can be of great help.

Final solution SATELLITE

richard
photorecall.net

[Ebobtron]

To add to "rfmmars" remarks look at the other TV or TVs you have. Do you see the same noise (it is called "snow"). If the others do not show it then rework your connections to the capture device. TV signal splitters are lossy and an amplifier maybe your only help. A software filter is only going to reduce detail in the clip best to try and boost the signal first.

[hartford]

That's not snow.

In each scan line, starting at pixel 86 or 87, and then about every 20
pixels thereafter, there is a vertical line of "garbage" about 6 pixels wide.

Adjust your monitor's brightness and contrast. Or copy the picture, do an edge detection and increase contrast; you'll see it.

[Jezreel]

I agree with the last reply, this is not normal snow. If you take a close look at the picture you’ll see that there are vertical lines of trash that start not at the left side of the picture but a considerable amount of lines to the right. This happens on all channels above 50, maybe on some others too but as the channels go down the lines start to get more and more diffused into the real picture. These lines do not appear on my TV which is right next to the pc. I am getting the signal straight from the roof and I use a splitter to split the signal between the pc and the TV. I believe this problem is due to noise, however it just may be accentuated by the crappyness of my card. The reason why I believe noise is part of the problem is I tried changing the connections, and when I separated the power cable from the coax it seemed to make it better on some channels, for example this lines are almost undetectable on channels 50-52.

[Ebobtron]

Those remarks would have helped in the first post, if you want me to see something point it out to me.

Vertical lines we once called jail bars were normally caused by coupling the horizontal sweep into the video. With modern TV, we have the switching power supplies of which most run at a higher freq. than the sweep stage, often a multiple of the sweep stage. Sweep stages and switching power supplies in TV sets often do not play well with others. Funny most of the rules about radiated interference are meant to protect the TV which outputs more interference that any three other electronic appliances. So try moving the TV, shut it down (unplug it). If the problem is the cheapness of your card then it is probably not shielded very well.

Good luck.

[Jezreel]

So just to update. i went out and got me a signal amplifier. It removed the bars on all channels, but it made the signal somewaht noisier, this I guess is from the quality of the amplifier, but its much better anyway. Thanks all for the help