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Discussion Starter · #1 ·
Very complicated question here, let me explain.


I want to use this switch box:

http://www.monoprice.com/products/pr...seq=1&format=2


But I don't want to use it as intended. Instead, what I want to do is use the YPbPr ports to pass RGB video (through RCA cables), and use the digital coax port to pass composite video (though RCA cables too of course).


The reason why I want to do this is because I have a monitor that only excepts RGBHV through BNC connectors coupled with a bunch of old consoles that output RGBs (RGB video plus composite video for sync). I plan on using this switch box then converting the final output to this switch box to BNC connectors to connect to the monitor.


The only issue I have with this plan is that I don't know if the "digital" coax port can pass composite video. I don't know anything about that port and I don't know if it operates full rail only or if it's actually a real analog full swing port. Nor do I know what the output capabilities of that port far (bandwidth, swing, etc). Does anybody have any input?
 

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From the knowledge base tab on the provided link:

Quote:
Question: Can I use it as a composite video switcher instead of component?


Answer: Yes, just use one of the component video ports instead of all three. Just make sure to use the same colored connector for each of your video connections.
 

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I don't know for sure but I see no reason the digital coax wouldn't work for composite video.

Actually I have one of these switchers in use, if you wanted I could try and put composite video on it's coax port and see if it makes it through and in good quality.

My only complaint about this switcher is it's electronic and requires the power to be on all the time(no on/off switch like MP's HDMI switchers). I would have preferred a manual switch but the ones I looked at weren't 4x1 and the price was very good with this switcher.
 

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Discussion Starter · #4 ·

Quote:
Originally Posted by jjeff /forum/post/19578117


I don't know for sure but I see no reason the digital coax wouldn't work for composite video.

Actually I have one of these switchers in use, if you wanted I could try and put composite video on it's coax port and see if it makes it through and in good quality.

My only complaint about this switcher is it's electronic and requires the power to be on all the time(no on/off switch like MP's HDMI switchers). I would have preferred a manual switch but the ones I looked at weren't 4x1 and the price was very good with this switcher.

Can you please try and report back? I don't mind having no on/off switch.
 

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Quote:
Originally Posted by FusionITR /forum/post/19577242


Can this coxal port in this component switch pass composite video? (very technical)


Very complicated question here, let me explain.



Does anybody have any input?

Actually I would be surprised if that switch box could not pass composite video through the digital audio port. Composite video would have lower bandwidth requirement but slightly higher voltage levels than digital audio. If the designer tried to keep it simple and the manufacturer didn't try to save some pennies, then there's a good chance that all the video and digital audio ports use the same high-bandwidth video Mux IC.


BTW not convinced that yours is is a "very technical" or "very complicated" question (although someone apparently didn't get it).


Regards
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by blue_z /forum/post/19579730


Actually I would be surprised if that switch box could not pass composite video through the digital audio port. Composite video would have lower bandwidth requirement but slightly higher voltage levels than digital audio. If the designer tried to keep it simple and the manufacturer didn't try to save some pennies, then there's a good chance that all the video and digital audio ports use the same high-bandwidth video Mux IC.


BTW not convinced that yours is is a "very technical" or "very complicated" question (although someone apparently didn't get it).


Regards

Thanks for the info and I agree, I just wanted to make sure.


And this post may not be "very technical" as you stated, but also as you said half the replies in this post had nothing to do with what I ask and I already anticipated half of the people wouldn't know what I was talking about before I even made this post.
 

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I tried passing composite video through the coax jacks and it worked just fine
I ran a DVD players composite OUT into switcher coax audio INPUT1 and OUTPUT to my TV. Quality was as good as composite gets.

I was going to do a similar thing you're trying before I bought this switcher. I had a 4x1 switcher that had composite video, L&R audio along with S-video. I didn't really need stereo(just ability to hear something) so I was going to use the composite and L&R audio for the component 3 cables and use the S-video port for audio. I figured by the time I purchased 5 S-video to RCA converters I might just as well purchase this switcher. Again this switcher works great but my only complaint is it must be ON all the time, one more vampire on my power line
I tried unplugging it and while signal passed through the switch color was lost
probably only draws a few watts anyway.
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by jjeff /forum/post/19583798


I tried passing composite video through the coax jacks and it worked just fine
I ran a DVD players composite OUT into switcher coax audio INPUT1 and OUTPUT to my TV. Quality was as good as composite gets.

I was going to do a similar thing you're trying before I bought this switcher. I had a 4x1 switcher that had composite video, L&R audio along with S-video. I didn't really need stereo(just ability to hear something) so I was going to use the composite and L&R audio for the component 3 cables and use the S-video port for audio. I figured by the time I purchased 5 S-video to RCA converters I might just as well purchase this switcher. Again this switcher works great but my only complaint is it must be ON all the time, one more vampire on my power line
I tried unplugging it and while signal passed through the switch color was lost
probably only draws a few watts anyway.

Sweet thanks!!! I appreciate you trying this and getting back to me so soon. I'm going to order one right now!


And yeah, it's another vampire on the power line but honestly most electronics, especially something like a switcher, is a very small portion of your power bill. Appliances and the like are probably like 70% of your bill.
 

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It is worth a try, but it is also worth noting that I have tried doing this on other digital audio products, such as some baluns, and it didn't work out. Chances are good, but not 100% unless you ask someone who knows from the manufacturer.
 

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Quote:
Originally Posted by blue_z /forum/post/19579730


Composite video would have lower bandwidth requirement but slightly higher voltage levels than digital audio.

Other way around. CVBS is 4 MHz baseband for NTSC, or 5 MHz for PAL/SECAM, whereas SPDIF digital audio is about 1.5 MHz. In general, though, they tend to be handled by the same circuitry ; after all, before the CD player, people used to record PCM digital audio on their VCRs by formatting it into a dummy video stream.

Quote:
Originally Posted by walford /forum/post/19578263


I don't understand why you want to downscale HD 720p or 1080i resolutions from RGB componet to 480ii SD NTSC composite resolution.

Fortunately, that's not what he's doing. He's proposing to pass RGB through the YUV connectors, & composite sync through the digital audio port. That's the horizontal & vertical synchronizing signals, at whatever the appropriate frequencies happen to be for the video format he is outputting whether that be 59.94 & 15 734 Hz (480i), or 60.0 & 67 500 (1080p), or whatever.
 

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Discussion Starter · #13 ·
Quote:
Originally Posted by Sheer Lunacy
Fortunately, that's not what he's doing. He's proposing to pass RGB through the YUV connectors, & composite sync through the digital audio port. That's the horizontal & vertical synchronizing signals, at whatever the appropriate frequencies happen to be for the video format he is outputting whether that be 59.94 & 15 734 Hz (480i), or 60.0 & 67 500 (1080p), or whatever.
Exactly
 

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Discussion Starter · #15 ·
Update:


Composite video does indeed pass through the digital coax however the signal is somewhat attenuated and more jittery (I'm guessing the DC shifted input does not have appropiate level of DC restore circuitry, or simply the cap input is not high enough). When converting the composite video to composite sync using an LM1881 the sync isnt stable enough. The picture goes in and out of sync every few seconds.


However, I am able to convert the composite video signal to composite sync before passing through this switch and composite sync passes without problems so I am able to use this device. I just have to convert before the input instead of converting at the output.

I am sure 95% of people who read this post have no idea what I am talking about.
 
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