Hawes Mechanical Television Archive by James T. Hawes, AA9DT
Resistor Matrix Calculator for 2-Color TV Converter

Skip Introduction

♦ NOTICE. You should consider the resistor matrix circuit to be experimental. As far as the webmaster knows, no prototype exists. The Webmaster has built a similar circuit that produces red and cyan pictures. In this circuit, a shunt connects the green and blue outputs just before the right, or monitor block.

About the Calculator

The goal of the calculator below is to describe white in terms of only two colors. You define the formula for each color. The formula will be a combination of the primaries red, green and blue. (Three other primaries might work. Yet only these three are available in your computer monitor or TV.) The calculator totals user-entered percentages of six component colors (three primaries for each output color). The total must equal 100% (maximum luminance). The two output colors should be complementary (180° apart on the color wheel). If you enter non-complementary colors, the video display can't produce white or a normal gray scale. The calculator allows a...

  • Maximum of 4 entries.
  • Maximum of 2 entries per output color.
  • Minimum of 3 entries.
  • Minimum of 1 entry per output color.

Matrix. After the calculator provides output colors totals, you may build a resistor matrix. If practical, this matrix will allow viewing two-color pictures on your PC. The button <GET RESISTOR VALUES> sends the output of this calculator to another routine that designs the resistor matrix. Hints: A matrix is only necessary when you use a TV luminance contour (NTSC or CBS-Goldmark contour). To achieve a practical matrix, one of your output colors must be a primary color. That is, select red, green or blue only, and no second color.

Instructions

  1. Set the TV luminance contour. We recommend the <NTSC CONTOUR> (default; also for PAL/SECAM). Other Choices: A. To emulate colors on the 1951 CBS-Goldmark color standard, pick <CBS CONTOUR>. B. Suppose that the input video comes from a camera using the NTSC contour. But you want to see how the CBS system would have rendered the colors. Then pick <NTSC-to-CBS Converter Contour>. C. For no TV luminance contour, or a PC monitor contour, click <RGB CONTOUR>. (Doing this zeros the matrix resistor values.)

  2. A. To use a suggested color combination, click one of the "bonnet lady" images below. Or: B. To use a custom combination, fill in the blanks (below). For matrix accuracy, one chosen color must be a primary color (red, green or blue). For instance, this color combination will reproduce accurately: (Example 1) Avoid combinations like examples 2 and 3. Due to crosstalk, the matrix can't accurately reproduce these examples. (Example 2)     (Example 3)

  3. Select whether or not to round to standard resistor values. (Rounding introduces a slight error that probably won't be visible in your picture.)

  4. OPTIONAL: When your choices are satisfactory, click <GET RESISTOR VALUES>.

  5. OPTIONAL: To clear settings and start over, click <CLEAR FORM>.

1. Set TV luminance contour

(Select 1 contour)
NTSC Contour (Recommended for NTSC-PAL-SECAM) CBS Contour
NTSC-to-CBS Converter Contour RGB Contour (no matrix)

Rev 3-24-2013. Recommended color contour is NTSC contour & resistor matrix (R-30%; G-59%; B-11% of Y, Illuminant D65.)

2A. Click a Suggested Color Combination


Red & Cyan


Green & Magenta


Blue & Yellow

2B. Click a Custom Color Combination

Using Output Contour:    (read only)

Fill out the fields below.

For 1st Output Color, 

Enter percent of RED

 % Red

Fill out the fields below.

For 2nd Output Color, 

Enter percent of RED

 % Red

Enter percent of GREEN

 % Green

Enter percent of GREEN

 % Green

Enter percent of BLUE

 % Blue

Enter percent of BLUE

 % Blue

3. Optional: Choose to round resistor values

Round resistors to nearest 5% standard values.

Don't round resistor values.

4. Optional: Get resistor values & matrix

5. Optional: Clear form





Google Search
Web www.hawestv.com



♦ WARNING. This is your project. Your achievement is entirely yours. I assume no responsibility for your success in using methods on these pages. If you fail, the same is true. I neither make nor imply any warranty. I don't guarantee the accuracy or effectiveness of these methods. Parts, skill and assembly methods vary. So will your results. Proceed at your own risk.

♦ WARNING. Electronic projects can pose hazards. Soldering irons can burn you. Chassis paint and solder are poisons. Even with battery projects, wiring mistakes can start fires. If the schematic and description on this page baffle you, this project is too advanced. Try something else. Again, damages, injuries and errors are your responsibility. — The Webmaster

Copyright © 2012 by James T. Hawes. All rights reserved. Photo of woman in color buttons: Adapted from Philco art: Fink, Donald G. Color Television: Simplified Theory and Service Techniques. Philadelphia: Philco, 1956, p. 135. Retouching by James T. Hawes.
Color percentages for CBS Color System are from: Wentworth, John. Color Television Engineering. New York: McGraw-Hill, 1955, p. 252.

•URL: http://www.hawestv.com/mtv_2color/calc_r_matrix_2c.htm •Webmaster: James T. Hawes
•Revision—February, 2016 •Page design tools: HTML, Notepad, PhotoShop & Explorer