Improved composite video mod

[boardjunkie]

Just a note to those doing the LM318 based composite video output. Since the LM318 is getting scarce since its out of production, I found a "better mousetrap" using commonly available parts. You can use the LM310 (dedicated voltage follower) chip in the 318 circuit with no changes. In fact, if you're making one, you can omit the 27pf cap and 10k resistor in the feedback loop since the 310 is internally connected as a buffer. And, the 310 is rated to 20mhz as opposed to the 318's 15mhz. And....it blows the single transistor mod out of the water pix quality wise.

 

I'll be making up a batch of these boards soon, so if anyone is interested in one, let me know. They'll be cheap since I have plenty of stock on the supplies.

[+evg2000]

any chance of a schematic for dyi?

[boardjunkie]

any chance of a schematic for dyi?

 

 

Just use the LM318 circuit and omit the parts in the feedback loop (between pins 6 and 2).

 

http://www.a1k0n.net/projects/coleco/sch.html

 

Thats the commonly used op amp circuit.