Hey guys, my CTC 40 has an RCA Hi Lite CRT and my CTC 17 has a colorama CRT. The Hi Lite seems much brighter with vibrant color and the Colorama even though it looks good too it meeks to lack that extra bright vibrant raster. What were the differences between these two CRT's?

I have noticed that the Colorama CRT phosphers are much darker than the Hi Lite phosphers. I wonder if this has anything to do with lumens output.

The Hi-Lite was new tube and Colorama was a rebuild IIRC.

good to know, my recent RCA CTC 17 console has a 23v rca hi lite :)

Before making a general statement comparing the tubes, you need to compare some things about their construction and the sets they are in:

1) do the tubes have different optical transmission in the faceplate? (visibly different when the sets are off?) I presume this is what you mean by darker phosphors
2) are they being run at the same ultor voltage and beam current?

1) yes. The colorama CRT actually appears darker and the Hi Lite seems as though it may have a finer dot pitch.. Call me crazy. Could this be true or were the matrix all the same through out the years? If this is true then I can understand why the Hi Lite is brighter.

2) I believe so. Both sets pust roughly 23 to 24 kv to the anode cap and 5 k or so focus voltage.

Before making a general statement comparing the tubes, you need to compare some things about their construction and the sets they are in:

1) do the tubes have different optical transmission in the faceplate? (visibly different when the sets are off?) I presume this is what you mean by darker phosphors
2) are they being run at the same ultor voltage and beam current?

Oh and drive currents to the beams are within 10 volts of eachother between the two sets. My other ctc 17 I have installed a zenith 25xp22 CRT and it has excellent contrast and color and brightness too. Much like the Hi Lite

Also, they used different colors of bonded safety glass, and most were non-glare. The non-glare cut down on the brightness a LOT. It's a toss-up though; the non-glare was dim, but had better color and contrast. The plain face glass was bright, but not near a deep a picture, in my opinion.

Charles

Good point Charles! And the colorama CRT I have believe it or not is almost as dark as a trinitron CRT..