Re: [mythtv-users] Front end machine 30' away from TV/stero?
Date: Sun, 20 Feb 2005 11:13:36 -0500 From: Marc Sherman [EMAIL PROTECTED] Subject: [mythtv-users] Front end machine 30' away from TV/stero? To: Discussion about mythtv mythtv-users@mythtv.org Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=ISO-8859-1; format=flowed This is fairly off topic, please let me know if I should take it elsewhere. I'm setting up a mythtv system in my basement. I've got a server machine running 24/7 in a back room, about a 30' cable run distant from my TV/stereo. I'd like to be able to use that box as both front and backend, if at all possible. snip Thanks, - Marc My backend/frontend system is about 90' away from my TV (regular not HDTV). I thought I had sent my configuration to the mailing list earlier but I can't find it in the archives. So here is a summary. I run my svideo and audio signals over 10-BaseT. At each end I have a converter box I bought from svideo.com. It has svideo (for audio) RCA connectors. I believe the part number is 500017. For the infrared remote control I just used some old coax I had laying around and put connectors from Radio Shack on each end. The result is no noise at all from Myth system in the TV room. I have no problem at all with the TV quality but perhaps I'm not the most discriminating user. Good luck, Vince ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Front end machine 30' away from TV/stero?
I've run composite video over RG6 quad sheild previously (currently component (HDTV) over 3 RG6 Quad Sheild) over a distance of about 25 feet. I am using the F connector to RCA adapters you can pick up at Radio Shack. I have had no picture quality issues as long as you have good connections. I run line level audio over RG6 as well. I would take a guess that your issue is one of the following bad crimps or sub-par cable. I've found that the picture quality is very dependant on how good you are at crimping cable, I picked up a few hundred Thomas Betts snap and seal connectors with related tools on Ebay and although they were pricey, I don't have any picture quality issues. ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Front end machine 30' away from TV/stero?
This is fairly off topic, please let me know if I should take it elsewhere. I'm setting up a mythtv system in my basement. I've got a server machine running 24/7 in a back room, about a 30' cable run distant from my TV/stereo. I'd like to be able to use that box as both front and backend, if at all possible. I run my svideo and audio signals over 10-BaseT. At each end I have a converter box I bought from svideo.com. It has svideo (for audio) RCA connectors. I believe the part number is 500017. I'll second svideo and audio over Cat5 cable(or any twisted pair really). I used to run a 30 foot or line of svideo over Cat5. I didn't buy any converters, I just got connectors and soldered it together. An svideo cable has two grounds, and two signals, put one ground and one signal in each twisted pair, you won't lose too much signal. That's the magic of twisted pair. At a later time I made a dual stereo mini extender for the 4 speaker surround sound. Again, putting one ground and one signal in each twisted pair. That worked fine as well never tried audio and video together in the same wire but it might work. -- Anthony Vito [EMAIL PROTECTED] ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Front end machine 30' away from TV/stero?
I've got an old NVidia card (an Asus branded GForce2-MX400), and I've tried running the composite out from that card to the TV over a 30' coax cable with F-RCA converters on both ends -- under the assumption that the coax (RG6) cable would be better shielded than a standard RCA cable -- is this true? The resulting signal on the TV is very dirty, with distortion in the middle of the screen and bands that cycle top to bottom. Is there anything I can do (better cable, a signal amp, something else?) to get video from the server to the TV cleanly? Or am I stuck with needing a second computer for the frontend in the TV room? Based on your description of the dirty signal you're seeing on your TV it sounds very similar to the distortion I was getting at one point from a ground loop problem. My cable run was only about 6 feet, but the signal distortion was horrendous. It turned out that my backend had a three-prong grounded plug, but my tv and receiver both had two-prong ungrounded plugs. This was causing a ground loop when connecting the backend computer to the tv and stereo. I eventually solved this by picking up some 12-gauge copper wire from home depot and connecting the ground screws on the tv and stereo to the metal plate in the power outlet where the backend was plugged in. This brought the ground for all three devices into sync and removed the distortion I was seeing. Since plain copper wire is pretty cheap from home depot you may want to give this a try before changing out parts of your 30' run. If need be you can temporarily use some old speaker wire to try this out and see if it makes any difference before you go pick up new ground wire at home depot. I wouldn't leave that speaker wire in place for an extended period of time, but you should be able to use it to test. Brad ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Front end machine 30' away from TV/stero?
You can get decent audio performance (line level) out of ordinary cat 5 cable as long as you use a twisted pair. To be honest I'm not sure if coax is actually better at audio. I remember browsing a web site that suggested at those frequencies it was not, but without taking the time to actually try to seriously analyze the two or have the equipment to actually compare them, its hard to say. The place twisted pair will really shine is if your destination uses a differential connection like used on commercial microphone mixers. Those cables are usually twisted pair with an outside shield, but the key part is the twisted pair and the differential connection afaik. I have run microphone cables at least a couple hundred feet without any noticeable noise on the system. I suppose if you wanted to run an audio level link a really long distance you could probably just isolate it at one end from the ground with a small line level audio transformer. I set up something similar so I could listen to a web radio broadcast down in my garage by using an unused pair of phone wires. Of course there was a tiny amount of noise on the resulting system, but they were really cheap speakers and lacking a 1/8 jack I just bent the wires around the plug. Of course for video there is no substitute for coax other than perhaps another frontend. On Sun, 2005-02-20 at 18:30 -0500, Marc Sherman wrote: John Konitzer wrote: The RG6 cable may have a better shield, but it's a low impedance cable (50 ohm, I think). Composite video and 'line-in/out' audio are much higher impedance signals (~10 kohms?). Try a non-coax shielded cable to see if you get any improvement before buying an amp or another box. Are you sure about the impedance for composite video? I've found a lot of references that it's 75ohms, just like RG6 coax, such as: http://www.bluejeanscable.com/store/single/composite.htm - Marc ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
