Can I shield my own VGA cable?

[Joeschmoe]

This is either a really stupid question or a question tackled long ago. I bought a Belkin VGA replacement cable to go with a monitor I bought at a garage sale without a cable. The fricken cable cost me $17 at Best Buy, and when I got it home I noticed it didn't have the little plastic round thingy (must have a name, huh?) that keeps the signal clean. When I use the monitor above 640 x 480 it looks awful. There is lots of ghosting. That could be because the monitor is a piece of crap, but the guy said it had just been his work monitor and it is a Samsung Syncmaster 500b (a decent enough monitor).

So, let me cut to the chase. Is there anything I can do to improve my cable? Wrap it in lead? aluminum foil? We're talking cheap household solutions here...I already blew $17 bucks on the cable. I would appreciate a suggestion. Othwerwise, I posted a WTB over in the forums, and this puppy is going back to the store.

 

[Joeschmoe]

Come on guys. If it is a stupid idea, somebody tell me!
--James

 

[nam ng]

What video card are you using? This monitor is best at 1024x768@70Hz

 

[Joeschmoe]

It is a PCI tnt2 m64 32 Mb. The card works fine with my other monitor, the Syncmaster 955DF. But that monitor doesn't use the VGA replacement cable...

 

[nam ng]

The "plastic round thingy" you mentioned is a ferrite choke, it's job is suppresing common mode interferences, though with weakness of increasing crosstalks, ghostings... not lessen them.

I suggest you try adjusting the monitor, by selecting lower Color Temperature selection, then tone down contrast as far as it will go at the most satifactory brightness contrast setting. BTW do not exceed 1024x768 @70Hz, it's the maximal intended operating resolution for this monitor, above this will cause large drop in gamma efficiency, forcing increase in contrast, brightness to compensate which is degrading not improving ghosting artifacts.

 

[Joeschmoe]

I tried what you suggest and there is a definite improvement. However, the display doesn't look as good at it could with a higher color temp and more brightness/contrast. Anyway, thanks for the tip. I guess what I really need is a decent cable. Any recommended retailers?
--James

 

[nam ng]

What you need isn't a decent cable, a Belkin cable was more than sufficient for that monitor, one thing to check is the firmness of cable insertion, some often used connectors will occasionally have some pins get pushed-in out of normal positions, no longer make as good a connection and can also cause the problem.

One more thing you can do is using 800x600 @70Hz, the gamma curve will be more efficient which may allowed you to adjust the ghosting completely away.

The 3rd thing you can do is that... Older monitors have "harden filament", filament is the part that sourced the free electrons neccesary to cause the excitation glow required for display, if you look through the ventilation at the back of the tube neck, it's a glowing bulb even when you darken the screen.

Aging over time the filament became "harden" and no longer provide the same quantity of electrons as when new, my pass experiments showed a lost of little less than ~10% per 5yrs of age, causing a drop in gamma efficiency, which can be compensated by increasing the filament voltage very slightly.

 

[Joeschmoe]

I'm not sure it is noticably better at 800 x 600, so I'm sticking with 1024x768 because the other is just too big. What you said about the filament reminded me of an experiment we did in college physics (we were calculating the charge to mass ratio of the electron using an evacuated tube of mercury gas and a filament not unlike those found in a CRT.) So what you suggest as a voltage tweak to the filament makes sense (of course, it'll burn out faster too, right?). How would a non-techie go about making such an adjustment?

Also, are you sure it is not the cable? This thing is REALLY thin. The thinest monitor cable I have ever seen. And the back of the box recommends their "high performance monitor cable" for 19" monitors or "other high resolution applications" It is 28 AWG stranded tinned copper with PVC insulation. Monitor was manufactured in July 1997. If I could only borrow a nice cable to check...
--James

 

[Joeschmoe]

bump

 

[Joeschmoe]

NEW UPDATE:
I am virtually positive that it is indeed the cable: When I just turn the monitor on and I get the message "No Connection! Check Signal Cable" there is no ghosting!