Just found someone managed to replace CRT sucsesfully. May be we will overcome that too. Signal seems to be very clear.
Youtube Video

 

If the monitor has separate red, green, and blue inputs, use just one input for testing.
If this works we will show how to connect all three inputs if you want white.

 

Next few days will definitelly be fun !
Also can not express my feeling how special is to be here inside comunnity. Just cant

 

Next few days will definitelly be fun !
Also can not express my feeling how special is to be here inside comunnity. Just cant

Sooo you thinking it might output a MDA signal?
https://www.globalsources.com/CNC-controller/Video-monitor-converter-1169973385p.htm

 

Most CRT monitors are designed to accept H, V, and video signals.
You don't need any converter to make this work.

 

Just noticed VGA connector has separate ground for R,G and B. Do I have to connect any of those ?

Most CRT monitors are designed to accept H, V, and video signals.
You don't need any converter to make this work.

No . My dream is not to use another CRT.
My wish is to use H, V, and video signals to feed LCD via some device like this or any other

 

Just noticed VGA connector has separate ground for R,G and B. Do I have to connect any of those ?



No . My dream is not to use another CRT.
My wish is to use H, V, and video signals to feed LCD via some device like this or any otherView attachment 270195

https://sites.google.com/site/tandycocoloco/mda-cga-ega-to-vga

 

https://sites.google.com/site/tandycocoloco/mda-cga-ega-to-vga

Are you saying that simply connecting wires to VGA input will not work ?

 

Are you saying that simply connecting wires to VGA input will not work ?

A VGA monitor only works with a H-sync frequency of 31.5khz. If your car monitor works then the H-sync is more like 15khz to 17khz.
You will have better luck with a "TV" or the car monitor because they are built for 15750hz (depending on where you live).
Some TVs and Monitors will work with 15750 because there are/was so many things built for that frequency.
"VGA" is not "broadcast".

 

Are you saying that simply connecting wires to VGA input will not work ?

That is a BIG guess on my part but sure seems like your simple question is actually quite complicated.
Must be a reason people build massively complicated converters.
Certainly not for fun.
Well "just" fun.

Second "working" has a range ..

 

Just noticed VGA connector has separate ground for R,G and B. Do I have to connect any of those ?

Yes.

A VGA cable has three coax cables inside of it. All GNDs must be connected at both ends.

ak

 

small video of problem via DIY composite mixer on car monitor. Picture noisy and unstable.
Pic below :
Another problem is that some symbols must be in bold text indicating that function is active , but you hardly can tell what is what.
For example figures 12345670 - some of them are bold others not.
Or can it be that too low panel resolution is causing that ?

 

Now my osciloscope results are here. Measured at my DIY composite mixer input

Video signal does not make sense to me




What do you thing ?
Must notice that my experience using osciloscope is very close to zero.

 

Measured at my DIY composite mixer input

Please show a schematic of your mixer.

It looks like broadcast 15750hz H-sync. That is good news.
I think there are 3 levels in the video. Black/white/bold. Black=0%, white=80%, bold = too much. There is too little difference between the two top levels. I think the video is overdriving the monitor. Reducing the level so that bole=100% will cause white =50%.

You are doing very well.

 

Thanks for encouragement !
There what I have came up with ( actually colegue did ) :

 

Is there any reason why you can't use separate sync for the monitor?
You circuit is causing the distortion you see.
I need to get to work and do not have time right now, maybe someone can help.

 

The car monitor I am using now has composite input only.
I still has to try VGA monitor if I can find where I hide it.

 

I gave you instructions on how to connect directly to a VGA monitor.
Why do you need composite video?

Here is a simple circuit to generate composite video.

 

I gave you instructions on how to connect directly to a VGA monitor.
Why do you need composite video?

One of machines was equiped that way long ago. And we keep strugling looking at that distortions for years.
I will use your instructions as soon as I can find my VGA monitor. Seems I hide it better than I thought.
My wish was to find better way for another 4 machines we have.

 

Here is a simple circuit to generate composite video.

I don't know if you need to invert V-sync or not. This is a typical circuit. H-sync is inverted during V-sync. This circuit is not perfect, but it is close enough for most monitors.
Note there are no capacitors in the input and output.