Trying to apply color to a Black and white NTSC signal.

I currently have extracted the burst timing, and composite sync timing through LM1881.

Using HC4066, Bilateral Switch, I have produced the 3.579MHz oscillation on the colorburst timing.

When I was trying to sum the clamped NTSC signal from video camera and the color burst oscillation from the HC4066 with LF356N, High Bandwidth Op-amp, it just would not sum both of the signals.

I am using the LF356 as an inverting summer. Have tried various resistances as input 1k~100k ohms, however, the output was not visible....

Does anyone know how to solve this issue?

thanks

 

Trying to apply color to a Black and white NTSC signal.

I currently have extracted the burst timing, and composite sync timing through LM1881.

Using HC4066, Bilateral Switch, I have produced the 3.579MHz oscillation on the colorburst timing.

When I was trying to sum the clamped NTSC signal from video camera and the color burst oscillation from the HC4066 with LF356N, High Bandwidth Op-amp, it just would not sum both of the signals.

I am using the LF356 as an inverting summer. Have tried various resistances as input 1k~100k ohms, however, the output was not visible....

Does anyone know how to solve this issue?

thanks

Without a schematic, I won't even speculate.
Where are you getting the color information?

 

you cant make a black&white signal into a colour signal as there wont be any rgb information.

 

Where is the "color" coming from?

 

That's pretty easy. The LF356 is down to unity open loop gain (or zero loop gain) at the color burst frequency. You need a very fast amplifier.

Find an amplifier with an large open loop gain at 5 MHz. Those advertised as "video" amplifiers should work well. Even better, try making the circuit out of transistors. Transistor video amplifiers are all over the net.

You can add color to a monochrome signal. Just sum the subcarrier with the luminance channel and adjust the phase relative to the burst for the hue you want and the amplitude relative to the luminance amplitude for the degree of saturation you want.

 

That's pretty easy. The LF356 is down to unity open loop gain (or zero loop gain) at the color burst frequency. You need a very fast amplifier.

Find an amplifier with an large open loop gain at 5 MHz. Those advertised as "video" amplifiers should work well. Even better, try making the circuit out of transistors. Transistor video amplifiers are all over the net.

You can add color to a monochrome signal. Just sum the subcarrier with the luminance channel and adjust the phase relative to the burst for the hue you want and the amplitude relative to the luminance amplitude for the degree of saturation you want.

OK, so he can have a picture that's red, or chartreuse, or whatever, instead of just shades of gray. I wonder why he would want to do that?

 

Sepia, perhaps?