Hello, I need some advice on a working portacolor all tube

[Richard D]

Ok, we can get the jokes out of the way, why bother fixing the boat anchor, None of them ever worked out of the box, etc. I am doing a favor for a friend who knows that shipping it cost more than the tv is worth. It has sentimental value. After I give it a warm-up 15 minutes Everything looks ok, just ok. The focus is not perfect nor can I find any focus adjustment, be it a moveable wire or a pot. I do have the Sams for this model. Then while I am watching it, sometimes when the scene changes I get a blue band accross the screen next screen cut and it's back to "normal" for this set. The CRT is original, 43 week of 1968 and does not have a brightner. In order to get something resembling flesh tones I have to turn the tint control all the way clockwise. I did some tube tapping and could only find one that was noisey, sprayed the contacts and that problem went away. The Owner of this set is a very good friend of mine and I am ready to find a shop to rip me off. Some of the tubes have been replaced. I no longer have an oscilloscope or vectorscope(aren't friends great, I promise I will bring it right back) I am thinking of just start replacing caps in the video,demod, and chroma sections. Thanks To All For Reading My Rant.
Richard D

[Sandy G]

No need to apologise-my folks had a Porta-Potty from '66 til we got the 1st Sony Trinitron in '72. Little guy was a trooper. Terrible picture unless the signal was REAL good. Would get hot as a firecracker, but IIRC, we never did a THING to it, until the very last, & then it seemed to have fifty-eleven things go wrong w/it. People laff at 'em now, but they were kinda Somethin' Special back in '66-a more-or-less TRULY portable color TV. Ours was on prolly something like 14-18 hrs a day, 7 days. I think all the while it had been fed 130volts-we're 5 miles away from a TVA generating plant, & you tend to get lots of "extra juice"...-Sandy G.

[yagosaga]

Originally Posted by Richard D

The focus is not perfect nor can I find any focus adjustment, be it a moveable wire or a pot.

The GE porta-color was my first NTSC set, an early one dated April, 1967. It has no focus swich, but in my schematics (model 213cwd) the focus can be soldered at different currents: 270 volts d.c., 670 booster voltage or to the ground. Comment: "connect focus lead, R116, to terminal which provides best focus."
The set has an inconsistent black level which vary with the programme. In the first time I adjust brightness every time when the camera changes the scene until I found that there is no black level automatic in this set.

[andy]

I have a scan of a service manual to a portacolor if you need it. It's a more recent model than yours which uses a different CRT that has a focus pot, but otherwise it should be the same. You should be able to improve things a lot by doing a proper gray scale adjustment and changing the focus tap to the bes setting. These sets are always wayyyyyy out of adjustment when I get them. Don't expect a perfect picture. These always produce a washed out blurry picture. Be sure to replce the big ceramic cap near the horizontal output tube.