View Single Post
  #10  
Old 09-06-2005, 01:20 PM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 7,792
Quote:
Originally Posted by Chad Hauris
Isn't this how the modern sets do...the chroma and luminance signals are mixed before they get to the CRT? Seems like in most of the tube type sets the mixing actually occurs in the crt itself with the chroma at the grids and the luminance at the cathodes.
Yep - Several things combined to make solid-state sets go back to RGB cathode drive:
1) CRT's with unitized guns, where only the cathodes were separate for the three colors;
2) cheaper to have only 3 high-voltage video output transistors instead of 4
3) with ICs: definitely cheaper to do all matrixing to RGB in the IC - also, at this point, the chroma and luma gain controls could be electonically ganged so they go up and down together without changing color saturation when the "picture" control is turned.

I can't remember if I ever saw a design implementing a "picture" control with mechanically ganged "contrast" and "color" controls - anybody remember such a thing?
Reply With Quote
Audiokarma