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CKF April 25th 08 12:57 PM

Component-VGA cable
 
I'd like to run my satellite box into my VGA input on my TV. Will a
component video to VGA cable work for this, or does it only work in the
opposite direction (computer to TV)? I've seen some cables on ebay very
cheap, but the auction description refers to "hooking up your computer
to a TV through the component input", not the other way.

Thanks,

Chris

Incstlouis April 25th 08 08:13 PM

Quote:

Originally Posted by CKF (Post 423664)
I'd like to run my satellite box into my VGA input on my TV. Will a
component video to VGA cable work for this, or does it only work in the
opposite direction (computer to TV)? I've seen some cables on ebay very
cheap, but the auction description refers to "hooking up your computer
to a TV through the component input", not the other way.

Thanks,

Chris


Chris - You may be able to do this if your TV can transcode to/from component to VGA. You'll have to check the owners manual or call the Mfg. of your TV.

www.showmecables.com has them in 6, 12 & 25 ft. lengths.

Here is a direct link:
http://www.showmecables.com/viewItem.asp?idProduct=2597

[email protected] April 25th 08 11:44 PM

Component-VGA cable
 
On Fri, 25 Apr 2008 10:57:18 GMT CKF wrote:

| I'd like to run my satellite box into my VGA input on my TV. Will a
| component video to VGA cable work for this, or does it only work in the
| opposite direction (computer to TV)? I've seen some cables on ebay very
| cheap, but the auction description refers to "hooking up your computer
| to a TV through the component input", not the other way.

Computer analog output is 3 discrete red, green, and blue outputs.

Video component output is 3 complex signals. One of them is the monochrome or
luminance signal, suitable by itself to make a correct black and white image
which is made from a specific proportion of each color. The other two signals
are differences for blue and red from that luminance signal. The signals are
mixed in certain proportions to convert VGA's pure RGB color space into video's
complex YPbPr color space.

I do not know if this mixing needs to be active, or if a passive mixer can be
made. If it is possible to do resistor network passive, that _might_ be
reversable. But I don't know that it is even possible.

If it is done as an active circuit (which would not take much), it would be
doing so powered by pin 9 (+5v) of the VGA DE-15 connector. That would not
be reversable for 2 reasons: 1: an active circuit is directional 2: power
would be coming from the VGA source.

Since video component sources do not provide power, I don't see a way to make
a converter without a separate power source.

If you have a spare HDMI input on the TV and an HDMI output on the satellite
box, or can get a replacement box with one, that is the better route to go.
If you have a space DVI input on the TV, it can be adapted to HDMI (all the
video digital signals are the same between DVI and HDMI) if a separate means
to feed the audio is provided.

If you want someone to figure out a possible clever solution for you, tell us
what are all the inputs you have available, and all the video sources you want
to connect with a list of what output types each of them has. Such solutions
may include passive or active devices you might need to purchase.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Tam April 26th 08 01:10 AM

Component-VGA cable
 



wrote in message
...
On Fri, 25 Apr 2008 10:57:18 GMT CKF wrote:

| I'd like to run my satellite box into my VGA input on my TV. Will a
| component video to VGA cable work for this, or does it only work in the
| opposite direction (computer to TV)? I've seen some cables on ebay very
| cheap, but the auction description refers to "hooking up your computer
| to a TV through the component input", not the other way.

Computer analog output is 3 discrete red, green, and blue outputs.

Video component output is 3 complex signals. One of them is the
monochrome or
luminance signal, suitable by itself to make a correct black and white
image
which is made from a specific proportion of each color. The other two
signals
are differences for blue and red from that luminance signal. The signals
are
mixed in certain proportions to convert VGA's pure RGB color space into
video's
complex YPbPr color space.

I do not know if this mixing needs to be active, or if a passive mixer can
be
made. If it is possible to do resistor network passive, that _might_ be
reversable. But I don't know that it is even possible.

If it is done as an active circuit (which would not take much), it would
be
doing so powered by pin 9 (+5v) of the VGA DE-15 connector. That would
not
be reversable for 2 reasons: 1: an active circuit is directional 2:
power
would be coming from the VGA source.

Since video component sources do not provide power, I don't see a way to
make
a converter without a separate power source.

If you have a spare HDMI input on the TV and an HDMI output on the
satellite
box, or can get a replacement box with one, that is the better route to
go.
If you have a space DVI input on the TV, it can be adapted to HDMI (all
the
video digital signals are the same between DVI and HDMI) if a separate
means
to feed the audio is provided.

If you want someone to figure out a possible clever solution for you, tell
us
what are all the inputs you have available, and all the video sources you
want
to connect with a list of what output types each of them has. Such
solutions
may include passive or active devices you might need to purchase.

--
|WARNING: Due to extreme spam, I no longer see any articles originating
from |
| Google Groups. If you want your postings to be seen by more
readers |
| you will need to find a different place to post on Usenet.
|
| Phil Howard KA9WGN (email for humans: first name in lower case at
ipal.net) |


I think it could be done passively, but it would not be reversible. Think of
a mixing valve with yellow and blue paint going in and green coming out.
Running it backwards with green going in would not give you blue and yellow
out.

Tam/WB2TT


CKF April 26th 08 01:13 AM

Component-VGA cable
 
wrote:
On Fri, 25 Apr 2008 10:57:18 GMT CKF wrote:

| I'd like to run my satellite box into my VGA input on my TV. Will a
| component video to VGA cable work for this, or does it only work in the
| opposite direction (computer to TV)? I've seen some cables on ebay very
| cheap, but the auction description refers to "hooking up your computer
| to a TV through the component input", not the other way.

Computer analog output is 3 discrete red, green, and blue outputs.

Video component output is 3 complex signals. One of them is the monochrome or
luminance signal, suitable by itself to make a correct black and white image
which is made from a specific proportion of each color. The other two signals
are differences for blue and red from that luminance signal. The signals are
mixed in certain proportions to convert VGA's pure RGB color space into video's
complex YPbPr color space.

I do not know if this mixing needs to be active, or if a passive mixer can be
made. If it is possible to do resistor network passive, that _might_ be
reversable. But I don't know that it is even possible.

If it is done as an active circuit (which would not take much), it would be
doing so powered by pin 9 (+5v) of the VGA DE-15 connector. That would not
be reversable for 2 reasons: 1: an active circuit is directional 2: power
would be coming from the VGA source.

Since video component sources do not provide power, I don't see a way to make
a converter without a separate power source.

If you have a spare HDMI input on the TV and an HDMI output on the satellite
box, or can get a replacement box with one, that is the better route to go.
If you have a space DVI input on the TV, it can be adapted to HDMI (all the
video digital signals are the same between DVI and HDMI) if a separate means
to feed the audio is provided.

If you want someone to figure out a possible clever solution for you, tell us
what are all the inputs you have available, and all the video sources you want
to connect with a list of what output types each of them has. Such solutions
may include passive or active devices you might need to purchase.

My TV has an HDMI input (in use, DVD player), VGA input, VGA Component
input (I don't know what this is), Coaxial, Composite, S-Video, and
Component (in use with Switcher Box for DirecTV, X-Box, and PS2). I was
hoping to figure out a way to run the DirecTV HD box to the TV through
the VGA or some other input and keep an HD signal. I ran it with the
S-Video just to see what it looked like, but it was obviously not HD.
If you have any reasonably inexpensive suggestions it would be great.

Thanks,

Chris

WGD April 26th 08 01:31 AM

Component-VGA cable
 
If I recall correctly, component video can come in two different versions
(and when MII was around, three versions). Component COULD be RGBHV or
color difference, as one poster noted. (R-Y, B-Y, & Y). When we talk about
component, aren't we really, (Usually ??) talking about RGBHV? (or
sometimes RGB with Sync on Green)?

Thus if one has a simple RGBHV (*component*), then we are talking about some
minor level differences, primarily a connector difference!

For years I used RGBHV (five-wire) cables with BNCs on one send and a std
VGA 15-pin on the other.

Wouldn't this work for CKF's question?

OR are all component video inputs to TVs these days color difference
signals (Pr R-Y, Pb B-Y, Y). For this writer, I have stayed with HDMI
all the way.

Wayne



"CKF" wrote in message
news:[email protected]
I'd like to run my satellite box into my VGA input on my TV. Will a
component video to VGA cable work for this, or does it only work in the
opposite direction (computer to TV)? I've seen some cables on ebay very
cheap, but the auction description refers to "hooking up your computer to
a TV through the component input", not the other way.

Thanks,

Chris




Kirk James April 26th 08 07:18 AM

Component-VGA cable
 
CKF brought next idea :
I'd like to run my satellite box into my VGA input on my TV. Will a
component video to VGA cable work for this, or does it only work in the
opposite direction (computer to TV)? I've seen some cables on ebay very
cheap, but the auction description refers to "hooking up your computer to a
TV through the component input", not the other way.

Thanks,

Chris



If your satellite receiver/DVR has HDMI output, you might want to
consider an HDMI switch.



[email protected] April 26th 08 09:08 AM

Component-VGA cable
 
On Fri, 25 Apr 2008 19:10:57 -0400 Tam wrote:

| I think it could be done passively, but it would not be reversible. Think of
| a mixing valve with yellow and blue paint going in and green coming out.
| Running it backwards with green going in would not give you blue and yellow
| out.

I think it could not be done passively, at least not with resistors, since
there is some subtraction involved. If it could, think of a ring of six
resistors of appropriate values. At junctions 1, 3, nad 5, we connect the
three signals of one end. At junctions 2, 4, and 6, we connect the three
signals of the other end. Selecting the values would be the issue. And I
don't know that it would work in either direction.

Maybe with transformers? But there is DC bias in the signal, so I think that
is out, too.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

[email protected] April 26th 08 09:12 AM

Component-VGA cable
 
On Fri, 25 Apr 2008 23:13:00 GMT CKF wrote:

| My TV has an HDMI input (in use, DVD player), VGA input, VGA Component
| input (I don't know what this is), Coaxial, Composite, S-Video, and
| Component (in use with Switcher Box for DirecTV, X-Box, and PS2). I was
| hoping to figure out a way to run the DirecTV HD box to the TV through
| the VGA or some other input and keep an HD signal. I ran it with the
| S-Video just to see what it looked like, but it was obviously not HD.
| If you have any reasonably inexpensive suggestions it would be great.

VGA is a kind of component. So having "VGA" and "VGA component" does not make
much sense. What kind of connector is it? A 15-pin 3-row D-sub (DE-15)?

A switcher box as you have now for component would have been my suggestion.
Otherwise it would be some very rare (and expensive) active conversion device.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

pj April 26th 08 05:51 PM

Component-VGA cable
 
Kirk James wrote:
CKF brought next idea :
I'd like to run my satellite box into my VGA input on my TV. Will a
component video to VGA cable work for this, or does it only work in
the opposite direction (computer to TV)? I've seen some cables on
ebay very cheap, but the auction description refers to "hooking up
your computer to a TV through the component input", not the other way.

Thanks,

Chris



If your satellite receiver/DVR has HDMI output, you might want to
consider an HDMI switch.


Kirk's solution has another advantage.

The vga (D-15) input on my HDTV is scaled at 1:1
pixels. (So, image size is set by changing the
resolution on the attached personal computer.)

My input channels that have HDMI/DVI
connections provide for automatic upscaling or
downscaling to better fill or not overrun the
display.

An older sattelite box might have a DVI output
rather than HDMI. DVI-to-HDMI cables are plentiful.

--
pj

[email protected] April 27th 08 07:55 AM

Component-VGA cable
 
On Sat, 26 Apr 2008 08:51:27 -0700 pj wrote:
| Kirk James wrote:
| CKF brought next idea :
| I'd like to run my satellite box into my VGA input on my TV. Will a
| component video to VGA cable work for this, or does it only work in
| the opposite direction (computer to TV)? I've seen some cables on
| ebay very cheap, but the auction description refers to "hooking up
| your computer to a TV through the component input", not the other way.
|
| Thanks,
|
| Chris
|
|
| If your satellite receiver/DVR has HDMI output, you might want to
| consider an HDMI switch.
|
|
| Kirk's solution has another advantage.
|
| The vga (D-15) input on my HDTV is scaled at 1:1
| pixels. (So, image size is set by changing the
| resolution on the attached personal computer.)

In analog, there is no pixel clocking. So the TV has to guess at what the
number of pixels is, or let the user figure it out through the clock rate
control.

It is plausible to make some guesses. The TV logic could assume the computer
is outputting 4:3 and adjust the pixels accordingly, using the left and right
video edges to find the first and last pixel.

How that would behave on a non-computer video source I cannot say.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |


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