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Discussion Starter · #1 ·
OK,


I have a HTPC using ATI 9600XT AGP board driving a Sony VPLHS20 PJ thru DVI. I also have a Gefen 1:2 DVI splitter/hub to drive the 40ft+ cable length cleanly. The added advantage I have with this hub is I use the second output to loop back to a FP Monitor on top of my HTPC for debug. The native res of the PJ and FP are the same so I get to see what is going on with the PJ 1:1.


Anyway, I'm looking to change my config to run the output of the HTPC into a Component Switch. This will allow me to drive many 16:9 LCD TVs in my house...as well as the PJ. I have the ATI DVI-to-HDTV adapter but my question is.....can I put this on the output of my Gefen Hub DVI port ? I've enabled the 720P drivers (Cat6.12) and my idea is to run DVI cable from the 9600XT to the hub......then output #1 has the Adapter on it and component cable plugged in going to switch....hub output #2 would be DVI cable to FP Mon. My concern is that this adapter is not doing a D/A conversion but instead using analog from the DVI ? If so, I assume the component would still work but not the DVI back to the FP monitor ? What is this adapter really doing ? Also, if it is analog from 9600XT DVI would this pass through and the FP mon see anyway ?


Here is my hub: http://www.gefen.com/kvm/product.jsp?prod_id=2987


Thanks.
 

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Discussion Starter · #5 ·

Quote:
Originally Posted by Targus /forum/post/0


It adapts the DVI connector to RCA's.

There is no format conversion within the adaptor, the video card must be able to output component video, on the analog pins in the DVI connector.

My gfx card is a ATI 9600XT which this adapter says it supports. Also, I have ATI Catalyst Driver & Control Center installed and I have enabled the 720P driver which I assume outputs the timings. My question is how do you enable and analog output from the DVI Gfx output or does this just happen automatically when it sees the adapter on bootup ? I was hoping the adapter took the digital DVI-D signal and converted to analog....but if it is just taking an already 720P analog timed signal which just is on the analog pins of the DVI-I connector then I need to know. If so, see below..................


I found out my Gefen Hub (not one in link) does allow for analog thru DVI...basically DVI-A support. So, assuming output from the PC is analog timed in 720P thru Cat Driver can I do the below ?


9600XT (DVI Port)==(DVI-I Cable)=>HUB


then.................


1:2 HUB

DVI Output #1 ==>DVI/YPbPr Adapter==(component cable)=>Switch

DVI Output #2 ==>DVI-A to DSub15 VGA cable==>FP Mon VGA DSub Port


Thanks.
 

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Discussion Starter · #7 ·
So, I got my DVI on my PC to output analog RGB. ATI has an adapter I had which is DVI-I to RGB D-Sub. I'm now about to run a DVI-I cable from my PC to my Hub that I did find the documentation on and says it will carry analog over DVI. My plan is to use/move the ATI DVI-RGB adapter on output one to my FP Mon and the other ATI DVI/Component on output #2. My theory is now that analog RGB is going to the hub the two convertors (DVI to RGB is just a physical wiring thing) and the DVI-Component is timing and see if it works. I can run 720P timings from my CAT drivers so if this works I can run the timings needed for the PJ.
 

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The DVI-I to YPrPb component dongle is also just a physical wiring thing just like the DVI-RGB component Dongle is in, fact they are probably the same dongle. The issues is what protocol does the Integrated DVI-I connector support on the 4 analog pins YPrPB or RGB component and this is determined by the graphics card manufacturer. Yes it is possible to have the separate analog and DVI interfaces on the adapter connected and active to two different displays one analog and on digital at the same time, however I don't know where you will get a dongle that will separate the intefaces apart so yu can connect both a DVI-D cable and a component (3 wire RCA) cable.
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by walford /forum/post/0


The DVI-I to YPrPb component dongle is also just a physical wiring thing just like the DVI-RGB component Dongle is in, fact they are probably the same dongle. The issues is what protocol does the Integrated DVI-I connector support on the 4 analog pins YPrPB or RGB component and this is determined by the graphics card manufacturer. Yes it is possible to have the separate analog and DVI interfaces on the adapter connected and active to two different displays one analog and on digital at the same time, however I don't know where you will get a dongle that will separate the intefaces apart so yu can connect both a DVI-D cable and a component (3 wire RCA) cable.

How about this........I scrap the DVI-I hub and just do this................


ATI 9600XT card DVI-I port connected to ATI's DVI-I to 15-pin RGB convertor.
http://shop.ati.com/product.asp?sku=2538009

I know this sends out analog because I plugged a standard RGB cable in to it an my FP Mon and worked fine.


So, now I add a simple RGB 15pin Y splitter to the above and put the ATI RGB-to-YPbPr adapter
http://www.svideo.com/hdtvr8500.html

on one (this goes to my PJ) and standard RGB-to-RGB cable on the other which goes to my FP Mon.


What do you think ?
 

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Discussion Starter · #12 ·

Quote:
Originally Posted by Targus /forum/post/0


As mentioned, the adaptors are just pin convertors, they dont' actually transcode RGB to component.

Also, you can't passively "split" a video signal.


So, no and no.

Well it seems to work......the DVI-to-RGB gives me a analog signal I see on my FP Mon on RGB port. Also, the DVI-to-Component also gives me a analog signal I see on my PJ (although overscanned which I can fix in PowerStrip). The issue is these attempts/successes are single point-to-point efforts.....not split.


So, to your comment on "no passive video splitting" then why are there the passive VGA splitter cables that say to drive two monitors from one VGA port ? See this: http://www.pcconnection.com/ProductD...ourceID=k40132


If not then how about using this: http://www.trianglecables.com/1pcto2monvga.html


Lastly, since the RGB-to-Component or DVI-to-Component is just a physical wiring convertor (and assuming and can get a Y active or passive to work) would putting this on one port going to component of a display and just a standard RGB-RGB Dsub cable to FP Mon work ? I asume there is no feedback since this is just a physical connection.


Thanks.
 

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Some peoople have had sucess with passive VGA and component splitters. I have installed VGA splitters in several conference/training rooms without any problems. However, many others have had trouble since the resulting impedence of the two connections could not be handled by the source and splitters that amplified and isolated the outgoing signal had to be installed.
 

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Quote:
Originally Posted by walford /forum/post/0


Some peoople have had sucess with passive VGA and component splitters. I have installed VGA splitters in several conference/training rooms without any problems. However, many others have had trouble since the resulting impedence of the two connections could not be handled by the source and splitters that amplified and isolated the outgoing signal had to be installed.

I have used a passive splitter on the VGA output on a Radeon 9600 card and it

worked just fine, I could not see any degradation in PQ as a result of slitting the

signal.


wb
 

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Discussion Starter · #15 ·

Quote:
Originally Posted by wbrack /forum/post/0


I have used a passive splitter on the VGA output on a Radeon 9600 card and it

worked just fine, I could not see any degradation in PQ as a result of slitting the

signal.


wb

Cool...any chance you used RGB-To-Component convertor on one of the two outputs ?
 

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Quote:
Lastly, since the RGB-to-Component or DVI-to-Component is just a physical wiring convertor (and assuming and can get a Y active or passive to work) would putting this on one port going to component of a display and just a standard RGB-RGB Dsub cable to FP Mon work ? I asume there is no feedback since this is just a physical connection

If I understand you correctely, you want to split the VGA output, connect one side to a VGA monitor, and the other side to a component input.?

You need to transcode the VGA to component for this to work.
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by Targus /forum/post/0


If I understand you correctely, you want to split the VGA output, connect one side to a VGA monitor, and the other side to a component input.?

You need to transcode the VGA to component for this to work.

Targus


OK.....so this is how/where you lose me. This works already with my DVI-To-Component Convertor ( http://shop.ati.com/product.asp?sku=2537967 ) which you and others have said is nothing more than a physical wiring mapping....not a transcoding. I think this URL help alot in showing the C1 thru C4 connections for R,G,B,Sync,Ground ( http://support.ati.com/ics/support/d...asp?deptID=894 ). I DO already have my ATI Cat Drivers set for 720P timings. It appears all that is happening is the convertor is remapping the analog pins to different physical connection. I do get alot of overscan on the TV image but I can adjust this later with customized 720P driver in PowerStrip.


Thus, if this works....which it does....why could I not introduce a splitter before this "type" scenario to drive my FDP Mon with analog RGB and the other output with the Component convertor ? This time I will use this convertor since it is RGB: http://shop.ati.com/product.asp?sku=2537967


************************************************************ ****************************

Lastly, does anyone know if this ATI DVI-A to RGB adapter is bi-directional ? http://shop.ati.com/product.asp?sku=2538009 I assume like others it is a physical connection/wiring device but was wondering. Granted the connectors are male (DVI-I) and female (RGB) so they aren't really oriented for RGB to DVI-A but this could be overcome with gender changer. Also, I found this one: http://www.gefen.com/kvm/product.jsp?prod_id=2333 which appears to be oriented correctly.
 

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When you plug the DVi to component adaptor into the card, it signals the card to output component video.

When you plug the DVI to RGB (VGA) adaptor into the card, it signals the card to output RGBHV (VGA) .

If you split the VGA output, 'll get two VGA outputs (RGBHV), the adaptor doesn't convert this to component.
 

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Discussion Starter · #19 ·

Quote:
Originally Posted by Targus /forum/post/0


When you plug the DVi to component adaptor into the card, it signals the card to output component video.

When you plug the DVI to RGB (VGA) adaptor into the card, it signals the card to output RGBHV (VGA) .

If you split the VGA output, 'll get two VGA outputs (RGBHV), the adaptor doesn't convert this to component.

Oh....OK. So, if I want to have component to one source and VGA to another how about this.........

I use from the 9600XT's VGA port this Y splitter http://www.pcconnection.com/ProductD...ourceID=k40132

then of one of the splits use this transcoder http://www.digitalconnection.com/pro...video/9a60.asp and off the other just RGB to FP Mon ?


I also make sure I have my ATI driver set to 720P (1280x720 60Hz) then go back and use PowerStrip to play with the timings to reduce overscan.


What do you think ? Thanks for all the help.
 

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The transcoder will work.


The passive splitter will result in reduced amplitude video signals at each destination.

Use a distribution amp to do this properly.

Cideo transmission lines require the source and load termination to be matched. When you put two loads in parallel, like you are with the passive splitter, the resulting load resistance drops to 37.5 Ohms, resulting in more of the signal being dropped across the source resistor, and a lower then spec amplitude at the loads.
 
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