VGA to RGBHV?

[ben7]

Hello, I have a project in which I need to make a VGA to RGBHV converter (for TV).

I have the cable set up right now,
the VGA red goes to the TV red, the VGA green goes to the TV green, and the VGA blue goes to the TV blue. And the VS and HS signals go to the corresponding connections on the TVs input.

I have a signal on the TV, but its got a pinkish hue to it. With just the G and the sync signals it is in black and white. Adding the B gives a grey and blue picture, while adding the R gives it a red picture. It seems to all work ok except for the green signal, what do you think is the problem?

I dont think the TV needs sync on green, because the TV already has inputs for the VS and HS.

Go ahead, say it, I know you can just buy one of these converters from the internet, but I would like to see if I can make it myself.

 

[nsaspook]

Does your VGA signal have seperate H/V sync and what scan rate are you using to drive the TV.

 

[ben7]

Does your VGA signal have seperate H/V sync and what scan rate are you using to drive the TV.

Yes, and its 60hz refresh rate.

 

[ccurtis]

Just for fun, what do you see if you put the blue or red output into the green input, alone, leaving H and V connected for sync?

 

[ronsimpson]

A well designed TV or monitor should black level clamp and not care if there is sync or not on the video.
Some TVs clamp to what is most black and not to the black level. This would cause green to clamp on sync not on black. This should make the pictures to green not too red (pink).
What happens if you switch green and red? Does the picture become too green and not too red. (pink) I am trying to determine if your red gain is too high or if the sync on video is confusing the TV.

 

[ben7]

Hey, ok, I will have to wait until monday to test it out, but I will do what you have suggested and I will reply back what happens.