I have a cable tv conection at home.However,of late,the picture quality isn't that good.While there is no problem with the picture,no flickling etc, however,the colours keep getting inverted to those of negatives in photos.Could anybody tell me how to overcome this problem?

 

Did you try using another TV already? might be a glitch in your set.
If another TV has the same problems then the cable connection itself is at fault. Better call the cable company if this is the case. If their cabling is to blame they should fix it for free.

 

One common problem with channels that are locally broadcast as well as on cable - a bad connection allows both the signal from the transmitter and that which is delivered by the cable company to be received. The is a very slight difference in the timing so one image is offset from the other based on that timing difference. In a severe form it causes ghosts but with small timing differences it might cause your problem. Just a thought.

The cause is an opening in the cable or a connector. It will only happen on locally broadcast channels.

__________________
stevez

 

I understand what's the cause and the prob.What I need is a solution.Is it possible to make a circuit to tie the colours to the normal level rather than it keep inverting itself every few seconds?
Thanks

 

You need to share the cause and the prob. with us if you expect a solution.
BTW, is this PAL or NTSC? By the way you spelled "colour', I'm guessing PAL. If you don't know - what country are you in?

 

I believe its the cable company doing some adjustments to the signals.i called them up and they say so far,only i got this prob and there's noting much they can do for me except to give me a discount on my subscriptions.hence,it got nothing to do with my tv.maybe its the cable box unable to properly descramble the signals.any way to prevent the colours from inverting?

 

Exo asked if you have tried another TV. Have you?

 

Hi there,

I have worked in the cable industry for 16 years so I can probably try to help you out.

First of all, be aware that cable systems are usually very large and the probability of "color adjustments" is very low. The cable company receive the signals and they re- transmit them out to the cable plant. Any color adjustments are usually made by the channel provider at the source (where channel originates).

As Exo and steves pointed out, ghosting can be the problem caused by bad connections and a bad tv or vcr could also be the problem as well.

My suggestions:

Make shure all the connections that you have access to in your apartment or home are in good condition. The fittings should be skrewed onto your equipment with a 7/16'' wrench. (NOT TOO TIGHT)
If you have a VCR - play a known good videotape and observe the picture and sound quality If its o.k. then your tv is not likely the problem.

With the tv on, rattle the cables (lightly) in back of your tv set and see if there is any change in picture quality. Any "jumping around" of the picture will reflect a bad connection (not excluding the actual port on your tv or vcr) they go bad at times also.

If you are using a cable box, sometimes the cable box needs a certain amount of signal in order to descramble properly. Also , cable boxes go bad so as you see it can be a number of things.

Try these suggestions and if nothing works call the cable company . There service should be free.


Good Luck
Joey Hernandez
Headend Technician
TWC N.Y. N.Y.

 

Hi,
I have tried on another TV,and it don solve the prob.I don think it could be the connection thats causing the prob.I have adjusted the connections,and the fault remains.
As I mentioned,I believed the cable company purposely send some distortion signals to create this prob.hence I need a circuit to tie the signal constantly at that normal level.But how do I go about it?
Thanks.

 

Try typing Universal Descrambler in google.

They are illegal for altering cable signals but thats what they are for. I doubt the cable company is sending a scrabled signal on purpose unless you have not paid for that channel.