AVS Forum banner

Status
Not open for further replies.
1 - 9 of 9 Posts

·
Registered
Joined
·
130 Posts
Discussion Starter · #1 ·
Have a 3803 sending a component signal to a video projector via the component monitor out. I am using the 3803 to switch between 2 component sources, as well as 2 S-video sources. Denon claims the 3803 will 'upconvert' an S-video signal and send it out the component outputs. I have confirmed this is true.


My problem is this: the S-video sources exhibit 2 scrolling noise bars (for lack of a better words). These 'bars' are horizontal in nature, are fairly thick, extend all the way across the screen and move from top to bottom slowly. On a black screen, the bars appear to be dark gray. On a video image, these bars are purple-blue and yellow-purple. They are VERY obvious, and detract greatly from the picture.


I have confirmed this is a only a problem when using the Denon, and appears not to be cable related (the S cables I am using are custom made, 50' long, dual RG-59 with BNC ends converted to S-video). When the S-video feeds are connected directly from source to projector using the same cables the lines go away completely. The component switching from the Denon seems fine, as it does not present the above problem.


I have not tested the S-video switching on the Denon to see if the noise bars are present. In other words, I have not tried taking the S-video monitor out and running it to my projector. I have only tried the component monitor out to my projector and relied on the internal conversion from the Denon for my particular needs.


Perhaps it is not so noticable on a small screen. I am using a 110" diag. screen.


Has anyone else experienced this problem?
 

·
Registered
Joined
·
27,961 Posts
Sounds like a ground loop issue, with maybe the S-video being more sensitive to it than the component. Are you using any sort of line conditioner? If you have analog cable anywhere near your system, have you tried disconnecting it?


I haven't seen rolling bars like this on the few attempts I've tried 'upconverting' S-video or composite on my 3803. However, I'm not all that fond of the upconversion quality (picture seems softer and colors are duller) so I generally don't use it.
 

·
Registered
Joined
·
69 Posts
I'm with Josh Z. Your problem screams ground loop or line noise (from things like florescent lights nearby). My 3803 is noise free on all outputs.


I can't remember, but I may have read somewhere in the manual about a 'processor reset' that may help, though I don't see how that would affect the video.
 

·
Registered
Joined
·
130 Posts
Discussion Starter · #4 ·
Thanks for the suggestions. I have quite a bit of experience with wiring and my wire management on this system is very good. No power cords run anywhere near A/V cables and if they had to cross, I would do so at a 90 degree angle. I am using a Panamax line conditioner, so not really sure what the cause of the problem is, unless there are issues with the Panamax.


Since I am happy with the direct feed to the projector, I'm going to leave it at that. I didnt really plan on using the 3803 for upconversion, just figured 'what the heck' if it had worked. Since Josh Z says he isnt impressed with the upconversion, I think that makes my choice all the more correct.

Thanks for the feedback.
 

·
Registered
Joined
·
3,755 Posts
It is interesting how this exact same thread keeps arising. This is at least the 5th time I've seen people report the same video problems with the 3803. Apparently this ground loop/line noise problem is quite prevalent.


It doesn't seem to be a design problem with the 3803, as a number of people are reporting excellent video resolution with no problems or noticable image degradation, even into very good HDTV sets.


Tom B.
 

·
Registered
Joined
·
224 Posts
Doc,


Can you tell us if your RG59's shielding is in contact with the connector on both ends of the cable ? It should only be connected to one end.


-RJ.
 

·
Registered
Joined
·
27,961 Posts
Quote:
Originally posted by doctorhifi
Since Josh Z says he isnt impressed with the upconversion, I think that makes my choice all the more correct.
It didn't do much for me, personally, but it's worth testing out on your own equipment to see what the results are.
 

·
Registered
Joined
·
130 Posts
Discussion Starter · #9 ·
RJ28462,


I believe the shield is in contact on both ends. Used special ends/compression tool to make cables. Involves stripping the RG59, removing 1/4" of dielectric, exposing 1/4 center conductor and folding shielding back. The instructions are very specific for these custom ends: do not remove the shielding. A center pin is then slid over the center conductor, then the whole cable with the center pin is slid into the outer BNC or RCA sleeve. The compression tool then completes the end.

We build cables using these ends and tool all the time and have had zero problems. In my earlier post you will notice that when this cable is connected directly to the source and than directly to the projector there are no bars whatsoever.


I didnt really buy the Denon with the upconversion in mind, just thought it would mean less cabling if it worked. It did not work for me, but I solved my problem another way. I would advise those who plan on buying this receiver for the upconversion to test it right away after they get it, and exercise their return option if they find the problem.
 
1 - 9 of 9 Posts
Status
Not open for further replies.
Top