We still use VITS as a test signal. If the signal is misadjusted it would cause the set to misadjust it's self. Also VITS is the only way to check the video with test signals without putting test signals on air. It really is very easy to keep NTSC adjusted corectly at the station, if the color phase or levels are off they are just lazy.

Steve

I don't touch the tint on my roundies... it stays pretty consistant between channels. Sometimes I a little surprised at how well it stays consistant.

I have the same intensity issues as mentioned above. One channel will have nice, rich color. The next channel will look weak. I don't like adjusting color controls everytime the channel changes... so for weak color channels... they get skipped. I, too, use the VCR as my cable box.

Being that they do so well keeping the tint the same between channels, you'd think they could do the same for the chroma levels.

Some old color sets deal better than others, for sure. I can tell the bad ones because they're the ones I have to keep adjusting, never able to get things "just right". Portacolors are an example, as is the all-tube 68 Motorola I have. My roundies do alright, except for the CTC-5 which requires babysitting. When I was watching the 69 DuMont the other day I was surprised at how accurate it was-I never had the urge to touch the tint.

We had a GE console with VIR. I never noticed any difference whether it was on or off; kinda neat to have a green led glowing on the front of your tv, especially when you're a kid! I do recall that GE bragged about winning an Emmy for coming up with VIR. There was also VIR II, but I don't remember what was special about it.

Isn't color intensity a lot more sensitive to antenna positioning, signal strength, and fine tuning than hue is? I get more difference in intensity using the old TVs' tuners than I do with a vcr, but I'm figuring a lot of that is is due to the fact that mechanical fine tuning in the sets is not as precise, nor locked in, as electronic tuners are. (?)
But I still have a couple of channels that consistently have less intensity, I always have to turn up the color on them, real drab looking. I don't know if that's antenna related or that's just how it is being broadcast.

If your vintage set doesn't have automatic color level control, you will definitely see differences off-air from channel to channel just due to antenna response and channel variaton (ghosts). The ghosts don't have to be very prominent in the monochrome to cause strong distortion in the chroma frequencies.

Regarding VIR, one thing that happened to it is that some stations started inserting it just before the transmitter, using it it as a indication of their transmitter's correctness. This broke the chain of correction, which was supposed to go all the way back to the originating studio.