Just picked up a 1975 13" Trinitron - Videokarma.org TV - Video

Trance88 · #1 10-26-2011, 04:23 PM

Hey Gang!
I just picked up a 1975 12" Sony Trinitron Knob Tuned TV for a whopping 85 cents at a thrift store this afternoon

Seems to work alright except for slightly jumpy volume and blue-ish picture. Is there any way to tone down the blue a little bit? The hue and color knobs overall don't seem to do much of anything.

The TV looks just like this one on the trinitron article on Wikipedia:
http://en.wikipedia.org/wiki/File:Trinitron.jpg

zenith2134 · #2 10-26-2011, 04:51 PM

Hey! Nice score and great price.
Econoquick was a type of instant-on which can degrade the crt a bit. However, Sony's system used less 'brute-force' and wasn't as harmful as older systems were.

To adjust the greyscale(fixing your blue tint) look for the R-G-B screen controls and the drive controls. Different Sonys of this time had different layouts. Sometimes you need not even remove the back cover to adjust this.

Set brite to half, contr at minimum, chroma to minimum and tune in snow or blank raster. Sometimes there's a service switch which collapses the raster, aiding in kine setup. Use the screen pots to adjust the picture for best black-and-white picture. The idea is to set all the guns for equal emission. If that cannot be accomplished, you won't achieve a nice b/w image, and the colors will be off once you add chroma. Once you do this, put up a contrasty picture and carefully adjust the drive controls for best whites. Good luck !!

Trance88 · #3 10-26-2011, 05:05 PM

Thanks for the info. I just remembered this TV actually came with its original pamphlet, but I left it at the store!!!!

ChrisW6ATV · #4 10-27-2011, 12:16 AM

Actually, Econoquick was a generation of Trinitron CRTs that warmed up quickly WITHOUT using any power when the set was turned off, thus the "econo" part of the name. I do not remember if earlier generations of Sony sets used any form of "instant-on" (CRT filament always powered) circuit.

zenith2134 · #5 10-27-2011, 12:17 AM

Hi my KV1712D certainly had instant on with filament as far as I recall. Could be wrong of course. But it was an Econoquick

Trance88 · #6 10-27-2011, 07:40 AM

My TV is a model: KV1203. I ran it for about a half hour last night. It gets a mediocre picture with the color turned all the way up, hue about half way.

zenith2134 · #7 10-27-2011, 01:05 PM

Hey I was referencing the KV1712 only because it too was an Econoquick. After searching through my post history at v.k. I've owned this 1203, a 1212, the 1712, a 1510, and a 1310. Most had very weak crt's but to be fair I found them after their lives were done. Yours might be a lower-hours set, but a chassis picture would help in determining that. The insides of the worn-out ones I've found were literally blackened(coated in black dust since the HV circuits attract it while the set is operating) so they were used up.

If the tube is good they make awesome pictures.
Until you complete the crt setup procedure outlined above it will never look right.

Oh, also-ran a search on econoquick and in an old thread two highly respected vk members, and myself were all at a loss as to whether or not the econoquick kept the filament lit at halfed power or was just a quick-heater type

Trance88 · #8 10-27-2011, 04:51 PM

I'll be giving the set a good look over and adjust it as needed sometime within the next day or two. I'll report back what I've found. I have some good news! I went back to that thrift store and found the original instruction manual pamphlet I left behind!

zenith2134 · #9 10-27-2011, 08:26 PM

That's ultra lucky to get the manual. Whomever donated this probably felt it had life left in it to include the manual. Would not mind finding another sony like this.

OT: seeing the conventional vs Trinitron diagram there made me think about the phosphors used....How did they differ from conventional inline-oriented phosphors in chemical composition? Zn? Al? Someone on this board must know.

Trance88 · #10 10-28-2011, 12:07 AM

Argh, I was just thinking about taking the back off this TV and I just started pulling the the two top knobs off (vertical and bright). At the last minute I decided to save taking it apart for later, so I put the two knobs back on. Now the brightness control pot just spins around almost freely. It now has barely any control over the brightness!! So, now I have the green-ish blue picture and no brightness control.

dieseljeep · #11 10-28-2011, 09:39 AM

Quote:

Originally Posted by Trance88

Argh, I was just thinking about taking the back off this TV and I just started pulling the the two top knobs off (vertical and bright). At the last minute I decided to save taking it apart for later, so I put the two knobs back on. Now the brightness control pot just spins around almost freely. It now has barely any control over the brightness!! So, now I have the green-ish blue picture and no brightness control.

You have to disassemble the set and look at the pot. You might have just pushed it apart. It would happen with Zeniths, with those long knobs.

Trance88 · #12 10-28-2011, 10:48 AM

I took the back off the TV and I found that there are no hidden pots for adjusting the picture. Everything is accessible with the cover on. I turned down the green which made the picture look so much better! The brightness control is now the only real problem.

I took a look at the broken pot for the brightness control. It sort of works still but you have to really play with it a to get it to do anything. it appears to be as it should but something inside it broke when I was pulling the knobs off. The stem of the pot is loose and it moves up and down and spins freely with no stop after a couple turns in each direction. It's gonna have to be replaced I'm guessing.

ChrisW6ATV · #13 10-28-2011, 03:58 PM

You may be able to remove and disassemble the potentiometer, and glue the shaft back together (with epoxy glue or similar). Or, look for a usable replacement pot. Since you now have a good picture, it should be worth the trouble.

Trance88 · #14 10-29-2011, 12:45 AM

It appears my best option is to just replace the pot. For now, it seems like the brightness is in a good spot. I got the colors almost exactly where they should be now. They're all nice and even. Just tonight I noticed a slightly yellow area on the right hand portion of the screen. Is it possible it could be in need of demagnetization or is there something possibly wrong with the phosphors?

Edit:
It does need a demagnetization. I tried demagnetizing it with an audio cassette demagnetizer, but it didn't seem to get rid of the discoloration. I really don't have anything else to try to demagnetize it with.

Trance88 · #15 10-30-2011, 11:10 AM

Ok, I got the colors adjusted as good as their gonna get. I have a feeling this set has a weak blue and red gun because no matter how much I play with the pots, there's always too much green. I currently have the green set all the way down and the blue and red are more than half way. If I turn the red up any more, the edges of things on the screen start to get a red-ish halo around them. Is there any way I can turn the green down any more, such as a master control somewhere on the set?