Another local Hoffman! COLOR! - Page 2 - Videokarma.org TV - Video

old_tv_nut · #1 07-14-2022, 10:48 AM

Quote:

Originally Posted by Electronic M

I always thought the color defeat switches on the various brands were to eliminate color on fringe color programs where the picture looked worse in color with snow than without color.

This philosophy might be followed by an engineer, but you can bet that the average owner would want that expensive color set to show even noisy color if it was available.

old_tv_nut · #2 07-14-2022, 11:18 AM

Quote:

Originally Posted by old_tv_nut

This philosophy might be followed by an engineer, but you can bet that the average owner would want that expensive color set to show even noisy color if it was available.

Of course, if the color AFC section was crappy and couldn't maintain lock under noisy conditions, that would certainly make you want to turn it off.

Yamamaya42 · #3 07-14-2022, 11:28 AM

I had never seen an adjustment like that before in a vintage TV, they must be rare, I have seen things like “color temperature settings” in LCD types, but in all the years since HS till now, this is the first time I have seen one in a tube type tv. :O

old_tv_nut · #4 07-14-2022, 11:45 AM

Quote:

Originally Posted by Yamamaya42

I had never seen an adjustment like that before in a vintage TV, they must be rare, I have seen things like “color temperature settings” in LCD types, but in all the years since HS till now, this is the first time I have seen one in a tube type tv. :O

The color temp setting in an LCD should not affect the tracking (that is, making shadow color different from highlight color) - it shouild be more like the drive settings in a CRT.

Note that with the excellent tracking stability of modern digital video hardware, deliberate separately controlled mistracking of highlights, midtones, and shadows is used in cinema and now even in Photoshop still image processing, where it is termed "color grading." It can be effective for setting a visual mood, but can also lead to fads like the strong orange-cyan look of some movies.

Yamamaya42 · #5 07-14-2022, 05:59 AM

What gets me is the 3 parallel lights, " Easy vision cinema " Say what?

Yamamaya42 · #6 07-14-2022, 06:21 AM

Well, that seems to be a pointless gimmick!

http://suzaku.live-evil.org/pointless.jpg
a 2nd CRT bias? and up front where the user can set it? :O
wow...

Yamamaya42 · #7 07-14-2022, 07:37 AM

Mind boggled...
To me it seems that adding that gimmick just gives a faster way to wear out the green/blue guns, having a master CRT bias pot on the back tied to the cathodes of the Y-AMPS, and another on the front, on the CRT green/blue G1 that the user can set?

This is prob why it was replaced with a new one in 1973.
No telling what condition it's in now, won't know till I pick it up on Saturday.

Electronic M · #8 07-14-2022, 11:05 AM

Quote:

Originally Posted by Yamamaya42

Mind boggled...
To me it seems that adding that gimmick just gives a faster way to wear out the green/blue guns, having a master CRT bias pot on the back tied to the cathodes of the Y-AMPS, and another on the front, on the CRT green/blue G1 that the user can set?

This is prob why it was replaced with a new one in 1973.
No telling what condition it's in now, won't know till I pick it up on Saturday.

It may have been the pot equivalent of the sepia switch om my old airline console. The idea was that on B&W films and TV shows older viewers that watched film before TV existed may prefer the look of sepia monochrome film stock and wish for a way that their TV could duplicate it...It looks stupid on color shows but I can see why some people might like it on monochrome shows.

old_tv_nut · #9 07-14-2022, 11:05 AM

Quote:

Originally Posted by Yamamaya42

Mind boggled...
To me it seems that adding that gimmick just gives a faster way to wear out the green/blue guns, having a master CRT bias pot on the back tied to the cathodes of the Y-AMPS, and another on the front, on the CRT green/blue G1 that the user can set?

This is prob why it was replaced with a new one in 1973.
No telling what condition it's in now, won't know till I pick it up on Saturday.

The Easy Vision Cinema doesn't affect drive levels, only tracking. Not sure of the visual effect with this hookup, but probably a variation between sepia, neutral and bluish shadows.

Some Motorola sets had this third color control (they called it Tint, and called the phase control Hue, rather than Tint, as RCA and everyone else did). In the Motorolas, it was actually useful if the viewer knew how to use it (which nobody did), because the DC coupled Motorola single tube demods tracking would change depending on the mismatching of the tube sections. In the cheaper models, the control was replaced with fixed resistors, and if you replaced the demod tube, you may have needed to adjust G2s to get neutral tracking again. The early rectangular high end Magnavoxes had an automatic color switch (with a fancier name I can't recall) that reduced green-purple color saturation and set the tracking to sepia. It reduced the variation on skin tones, but gave the "tan cowboy on a brown horse riding into an orange sunset" kind of picture.

nasadowsk · #10 07-14-2022, 03:23 PM

And yet, with all the “perfection” of ATSC,etc, it seems that the color still isn't always consistent. Go figure.

Almost The Same Color?

old_tv_nut · #11 07-14-2022, 04:30 PM

Quote:

Originally Posted by nasadowsk

And yet, with all the “perfection” of ATSC,etc, it seems that the color still isn't always consistent. Go figure.

Almost The Same Color?

Not the fault of the ATSC system, which does not deal with color except to transmit the bits.

AlanInSitges · #12 07-16-2022, 02:39 AM

Quote:

Originally Posted by nasadowsk

And yet, with all the “perfection” of ATSC,etc, it seems that the color still isn't always consistent. Go figure.

Almost The Same Color?

If this were Reddit we'd have 100 Europeans piling in right now to insist that PAL is vastly better at color, and that NO their TVs most certainly do not flicker!

Yamamaya42 · #13 07-16-2022, 02:28 PM

UPDATE!

I got it!!

VERY bad news , CRT is damaged!
pin 12 has been broken off of the base, this is prob why they dumped the set.

http://suzaku.live-evil.org/0716221359a.jpg
http://suzaku.live-evil.org/0716221403.jpg

good news is, I may have been able to fix it by tacking a wire to it.
http://suzaku.live-evil.org/0716221404.jpg

flyback looks OK

now I gotta start bringing back to life

Yamamaya42 · #14 07-16-2022, 05:55 PM

one very dirty looking RCA type looking chassis.

http://suzaku.live-evil.org/0716221748.jpg
http://suzaku.live-evil.org/0716221746a.jpg

Yamamaya42 · #15 07-17-2022, 02:39 AM

Progress, and step back, sort of? :O

After seeing the broken pin on the 25AP22A ( or so the sticker on it says ) , and not knowing if my fix attempt will work or not. I tried to bring the set slow up on Variac, this fond that C3 was REALLY bad, as it got hot VERY fast.

So I replaced all the sections of it, and tried again, THIS time power came up, I got hiss in the speaker, I heard vert start, but NO HV....

looked inside the HV cage, the HV rect was lit, and very hot. Pulled the cap off and got a good strong AC arc all over the place, removed the HV shunt, no change,,, BAD 3A3A, of which I have no spares.

so now, before I can make sure the CRT is any good, I must wait for the new 3A3C to get here so I can get HV up.