5 Replies Latest reply: Nov 9, 2010 7:55 PM by EdgarSwank RSS

    Noise bars in video. Any way to fix?

    EdgarSwank

      I have been getting noise bars in video from different sources, ReplayTV, Tivo, and both of the above viewed through Slingbox Classic. I just installed a powerline filter to filter 120 volt AC line power to all of the above, including the slingbox. This cured all my noise problems EXCEPT for viewing composite video through the slingbox. Viewing the Tivo through the coax Slinbox input now is OK. The two noise bars are approximately 60 cycle, but not exactly in synch with the video. Rather they travel slowly up or down the screen. The noise bars are made up of short black and white horizontal flecks, which are one scan line wide, dispersed randomly in the two noise bars, which are each perhaps a tenth the hight of the screen.. I wonder if anyone else has had a similar problem? I thought about trying to replace the Slingbox composite connector cable but can't find it in spare parts. Another candidate might be the power supply. Is there any way to buy these spare parts?

        • Re: Noise bars in video. Any way to fix?
          dbsguy Apprentice

          Are you using a amplifier to boost your signal (I take it this is a cabletv or matv source)? If so, the possible issue is a ground loop being caused by having either the amp or the slingbox plugged into different power outlets which vary in ground wire length. the easiest method of rectifyign the issue is to move them to where they can be powered by the same outlet. you can also test this theory out by simply removing the amp and barreling the lines togeather just to confirm that this is indeed the cause.

            • Re: Noise bars in video. Any way to fix?
              EdgarSwank

              Thanks for your response. Yes, I'm using amplifiers to boost & distribute the CATV (Comcast) signal input. But now this is plugged into the powerline filter (APC model C3) along with the slingbox and other components of my home theater. It also eliminated the noise bars from the CATV input of the Slingbox. Only the composite input still has the problem.

               

              My current theory is there is some problem with the Slingbox power supply, the only component between my powerline filter and the Slingbox. Like another user here, I found a generic 6v 2a power supply on Ebay and I'll try that when it arrives. Another possibility is the composite input cable for the Slingbox. I would try replacing that, but I can't find one to buy. The only other possibility would be some internal problem which would mean replacing the whole Slingbox.

                • Re: Noise bars in video. Any way to fix?
                  dbsguy Apprentice

                  You can use any composite cable for the slingbox, so stop by your local radioshack, bestbuy or large chain electronic store.

                   

                  However, I still think it's the amplifier from the symptoms presented; as how do you think I guessed you were infact using one to begin with? try disconnecting and bypassing the amp for now to verify as I stated. Although your entire system may have to be amplified to reduce or eliminate grain you should eliminate the problem if the amp is not of a good quality push pull manufacturing design. Over amplification can also cause this effect and may or maynot be seen on all tuners as some are more sensitive then others.

                    • Re: Noise bars in video. Any way to fix?
                      EdgarSwank

                      Thanks again for your reply.

                       

                      Cables with three (RWY) RCA plugs are common, but the end that plugs into the Slingbox is a complex phono plug of some kind that I haven't seen elsewhere (See attached photo).  Well, maybe you're right. I tried another search and found the following, designed for camcorders.

                       

                      http://www.amazon.com/Audio-Video-Composite-Camcorder-Optura/dp/B003V8SB9K

                      http://www.cablestogo.com/product.asp?cat_id=2019&sku=29148

                      http://www.adorama.com/SOVMC20FR.html?sid=1288283279175789

                       

                      The plug looks the same, except it's a right angle, but I'm not sure it would fit the Slingbox or not.

                       

                      As for the CATV amplifier, I tried disconnecting it from line power. The live video quality through my ReplayTV into the Slingbox deterioriated significantly, but the noise bars were still there. Also, the noise bars show up on material generated inside the ReplayTV, such as menus and the screensaver. Noise bars are visible only through the Slingbox. Connecting the same ReplayTV to the composite input of a regular TV does not have the problem.

                       

                      These noise bars look like RFI, with black & white flecks. The kind of interference bars I think you mean, caused by overmodulation or interference from a signal of a slightly different frequency, look different, no flecks, just light and dark smooth bands.

                       

                      I'm still hoping the replacement power supply will fix the problem.

                        • Re: Noise bars in video. Any way to fix?
                          EdgarSwank

                          The generic replacement power supply, "BRAND NEW 6V 2A AC / DC Power ac adapter Power supply" from seller yewelong on Ebay, price $7.59 including shippping from Hong Kong, arrived today. I'm happy to report it cleared up my noise problem completely. I think it also clear up an interference problem from noise the old PS injected into the house powerlines. So this problem is closed, and I think this is a good clue for anyone else who has electrical interference with a Slingbox.