right VGA cable?

L

Linea Recta

Today I bought a VGA cable for someone. Back at home I noticed the following
text on the blister: "designed to work with monitors smaller than 17
inches". No idea what this is about. It is to be used with a 21.6 monitor.

Anyone ever heard of cables specially for certain monitor sizes??




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P

Paul

Linea said:
Today I bought a VGA cable for someone. Back at home I noticed the following
text on the blister: "designed to work with monitors smaller than 17
inches". No idea what this is about. It is to be used with a 21.6 monitor.

Anyone ever heard of cables specially for certain monitor sizes??

This is some kind of half-assed admission that the coaxial
cables for RGB in the VGA cable, have a relatively high loss.

For any VGA cable, if you make it long enough, it gets
fuzzy above 1024x768 approximately. So if you run a 50 foot
or 100 foot cable somewhere, you would not expect to use
1600x1200 as a screen resolution choice, and view a good
quality image. Dropping to 1024x768, makes the lack of
sharpness less apparent.

Coax cables can be made in a range of qualities. So 50ft of
cable made from one flavor of internal coax, could be inferior
to another.

If the cable is relatively short, it really shouldn't
have an issue with this stuff. Bandwidth limitations
should be more apparent on long runs. If this is a
six foot cable between computer and monitor, it would
have to be almost "non-coaxial" to be that bad.
Note that, of the five signals RGBHV, many cables
carry H and V as twisted pairs or separate wire next
to a ground, while only RGB have the higher quality
coax used. In the following example, they use coax for
all five.

My old Sony Trinitron, came with a five coax cable and
individual BNC connectors. The cable has VGA on one
end, and separate coax span from the VGA to the monitor
itself. This causes the monitor to not support EDID
(the computer can't tell what resolutions it supports),
but the usage of separate coax, would allow longer cable
runs. So it is possible to make longer runs of cable,
or even fabricate your own - if the monitor, like my
Trinitron, had five BNC connectors on the back as
the input. So if I wanted to run a VGA signal the
absolutely longest distance without regeneration,
I might look into this approach. Since you can buy
VGA connectors with just pins on the back, you can
build your own cables if you want ("home coax" and all).

http://site.ambery.com/webgraph/VGA-5BNC-Cable.gif

You can certainly try the cable with your 21" monitor.
If the picture is too fuzzy, then you'll have your
answer. Run the monitor at native resolution, to
give the results a fair evaluation. Don't run it
at 1024x768 and "call it good". The native resolution
is the resolution where there is no scaling between
the incoming signal and the pixels on the screen,
so "one pixel coming in, gives one pixel going out".

And doing an "A-B" comparison, compare two VGA
cables, may give you some idea how much this
cheap cable is screwing up the quality.

Paul
 
L

Linea Recta

Paul said:
This is some kind of half-assed admission that the coaxial
cables for RGB in the VGA cable, have a relatively high loss.

For any VGA cable, if you make it long enough, it gets
fuzzy above 1024x768 approximately. So if you run a 50 foot
or 100 foot cable somewhere, you would not expect to use
1600x1200 as a screen resolution choice, and view a good
quality image. Dropping to 1024x768, makes the lack of
sharpness less apparent.

Coax cables can be made in a range of qualities. So 50ft of
cable made from one flavor of internal coax, could be inferior
to another.

If the cable is relatively short, it really shouldn't
have an issue with this stuff. Bandwidth limitations
should be more apparent on long runs. If this is a
six foot cable between computer and monitor, it would
have to be almost "non-coaxial" to be that bad.
Note that, of the five signals RGBHV, many cables
carry H and V as twisted pairs or separate wire next
to a ground, while only RGB have the higher quality
coax used. In the following example, they use coax for
all five.

My old Sony Trinitron, came with a five coax cable and
individual BNC connectors. The cable has VGA on one
end, and separate coax span from the VGA to the monitor
itself. This causes the monitor to not support EDID
(the computer can't tell what resolutions it supports),
but the usage of separate coax, would allow longer cable
runs. So it is possible to make longer runs of cable,
or even fabricate your own - if the monitor, like my
Trinitron, had five BNC connectors on the back as
the input. So if I wanted to run a VGA signal the
absolutely longest distance without regeneration,
I might look into this approach. Since you can buy
VGA connectors with just pins on the back, you can
build your own cables if you want ("home coax" and all).

http://site.ambery.com/webgraph/VGA-5BNC-Cable.gif

You can certainly try the cable with your 21" monitor.
If the picture is too fuzzy, then you'll have your
answer. Run the monitor at native resolution, to
give the results a fair evaluation. Don't run it
at 1024x768 and "call it good". The native resolution
is the resolution where there is no scaling between
the incoming signal and the pixels on the screen,
so "one pixel coming in, gives one pixel going out".

And doing an "A-B" comparison, compare two VGA
cables, may give you some idea how much this
cheap cable is screwing up the quality.

Paul



Thanks for your comprehensive reply. Where do you get that much time? :)
This cable wasn't especially cheap, at least that's not what I call 10,50
Euro.
The cable length is 1.8 meter, so not very long. Belkin F2N028cp

Going to connect it friday, Asus VW220TE to an old (only VGA) computer. I
expect it to be sufficient.



--
regards,

|\ /|
| \/ |@rk
\../
\/os
 
P

Paul

Linea said:
Thanks for your comprehensive reply. Where do you get that much time? :)
This cable wasn't especially cheap, at least that's not what I call
10,50 Euro.
The cable length is 1.8 meter, so not very long. Belkin F2N028cp

Going to connect it friday, Asus VW220TE to an old (only VGA) computer.
I expect it to be sufficient.

At that length, I doubt there will be an issue.

Let's hope they haven't figured out a new way to cut corners.

Paul
 
L

Linea Recta

Paul said:
At that length, I doubt there will be an issue.

Let's hope they haven't figured out a new way to cut corners.


The cable works fine!

Do you by any chance know a free utility to gather hardware specs from a (n
old) computer at a glance? Processor type/speed, memory, video, hard drives,
mobo etc.? We have 2 old PC's and would like to keep te best one.


--
regards,

|\ /|
| \/ |@rk
\../
\/os
 
C

Chris S.

Linea Recta said:
The cable works fine!

Do you by any chance know a free utility to gather hardware specs from a
(n old) computer at a glance? Processor type/speed, memory, video, hard
drives, mobo etc.? We have 2 old PC's and would like to keep te best one.
Belarc Advisor.
http://www.belarc.com/free_download.html

More information than you'll ever want to know!

Chris
 
P

Paul

Linea said:
The cable works fine!

Do you by any chance know a free utility to gather hardware specs from a
(n old) computer at a glance? Processor type/speed, memory, video, hard
drives, mobo etc.? We have 2 old PC's and would like to keep te best one.

There is Belarc Advisor. That's a half-decent summary.
You download a utility, and it prepares
a summary in HTML format, suitable for
viewing in a browser.

Sample output here.

http://www.cherryfield.net/resources/tips/belarc01.gif

The actual program is here.

http://www.belarc.com/free_download.html

*******

Lavalys Everest (I use the free Home Edition), used
to be good. It's commercial for an up to date version
now. And I understand the company or product has changed hands.

Still fun to play with.

http://www.majorgeeks.com/files/details/everest_free_edition.html

I notice another one on Majorgeeks, but haven't tried this.
This has a lot of extra functionality of one sort and another,
judging by the screenshots at the bottom. The right-most
screenshot, shows a CPU summary.

http://www.majorgeeks.com/files/details/aida64_extreme_edition.html

*******

CPU-Z from cpuid.com (no-install version), is good for CPU and memory.

*******

GPUZ is a good partner to go with Belarc, as it
can tell you about the video.

http://www.techpowerup.com/downloads/SysInfo/GPU-Z/

Here's a sample of that one. (The person who wrote
the program, puts new copies on Techpowerup, and I
think may have been a forum participant there.)
You should get enough numbers from this, to guess
at which has the better video.

http://gpuz.com/wp-content/uploads/2012/01/Why-would-I-want-to-Download-GPU-Z.png

*******

I'm kinda resigned to the fact I have to use multiple
of those kinds of programs, to get a complete picture.
It's not that the programmers don't try hard when
they write them, but the programmers seem to want
to "vomit" every detail they can find, rather than
collecting the things that matter and putting
them in a useful format. Everest would probably
be pretty good, but then, you'd have to pay for
a recent version that can identify everything for
you (that is, unless there's an eval version).

HTH,
Paul
 
L

Linea Recta

Thanks, I used Everest to generate some reports.




--
regards,

|\ /|
| \/ |@rk
\../
\/os
 

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