Hawes Mechanical Television Archive by James T. Hawes, AA9DT
How Col-R-Tel Works

Other Color Adapters

Contenders to the Color Crown. Other color adapters send the art on a different course. Colordaptor resembles the Col-R-Tel system, but Colordaptor includes a luminance delay line. Colordaptor also substitutes a three-phase, electronic switch (tristable) for the Col-R-Tel mechanical commutator. Systems by de Forest and Topping replace the scanning disc with a belt. The advantage of these belt systems is that they're smaller than comparable disc systems. Belt systems could adapt large CRT pictures.

De Forest's system is incompatible with NTSC color. Topping called his invention Spectrac. This elaborate color converter eliminates soldered connections inside the TV. Instead, converter signals come from a CRT socket adapter. Topping's system even works on TV sets with narrowband IF strips. A specially equalized bandpass amplifier restores the chroma signal to its proper proportions. Both systems have drawbacks. Topping's adapter makes a splash at the Consumer Electronics Show. That's its fifteen minutes of fame. No production models of either system exist.

Ed Reitan may still offer an partial CBS color system schematic (PDF) at... http://www.novia.net/~ereitan/cbs_tech_data.html.

Screen shot, Cliff Benham's working Colordaptor wheel
Screen shot from Cliff Benham's working Colordaptor wheel

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Color op art pattern represents color wheel.



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