View Full Version : port a color h4 chassis picture quality
ctc17 05-25-2010, 02:18 PM I brought back a re-branded GE H4 chassis PB re-brand set from SC. The set it NEW old stock, the tubes and crt test as such. After fixing a few whisker shorted pots its working.
The picture quality SUCKS though. I have heard these were not know for their picture quality...but, out of the box new this crappy. Its a full color picture its just overall poor.
Is this all I can expect?
freakaftr8 05-25-2010, 02:54 PM I had that H4 chassis, purity and convergence didn't look to hot and that set was my uncle's set. Never looked to good. But I just thought that was my set
jr_tech 05-25-2010, 03:17 PM I have never seen one that looked very sharp...IIRC the resolution spec on these sets (pixels/in) was not much different than that of a full-sized 21" round or 25/23" rectangular set... How does the picture of your porta color compare to just the center 10" of a 21" roundie? At the time it was very inexpensive for a color set and most were happy to have it.
jr
radiotvnut 05-25-2010, 03:25 PM I've never seen any porta color that looked too good. The best one that I saw was one of the later tube models from '76 that used the 10HE chassis.
Sandy G 05-25-2010, 06:02 PM Now you know why they call 'em "Porta-Potties"....
ctc17 05-25-2010, 06:43 PM The resolution is fowl. There is also weird kinda almost like color/video smear/bleeding. Another this thats irritating is, now that most everything is wide screen we have the black bar at top and bottom. Well the brightness of those black areas changes with the brightness of the scene.
Its not a bad looking set and the build quality doesnt seem as cheap as some of the Japan ripoffs. I have another H4 thats worse, I though it was just because it was high hours. Maybe not
freakaftr8 05-25-2010, 07:00 PM [QUOTE=ctc17;2974222]The resolution is fowl.
Yes dot pitch is the same as a 23V.
There is also weird kinda almost like color/video smear/bleeding.
--probably a bad cap in the G4 circuit.
Another this thats irritating is, now that most everything is wide screen we have the black bar at top and bottom. Well the brightness of those black areas changes with the brightness of the scene.
--This is most klikely the lack of DC restoration. Common to these early sets.
I have a 66 Zenith color 23" console upstairs that the DC resoration in that set is horrible. Try a white background with an image like a face in the foreground. The image of the face will most likely barely visiable.
Its not a bad looking set and the build quality doesnt seem as cheap as some of the Japan ripoffs. I have another H4 thats worse, I though it was just because it was high hours. Maybe not
--These lil sets were packed and suprisingly lasted a long time.
emmjay_1998 12-14-2010, 11:48 AM Well I can tell you. I have two Porta Colors. One from 1967 and one from 1976. The one from 1967 was from an ebay auction and did not work when I got it but just needed a new Horiz Ouput tube. It seems to work fin except the horiz seems a little uneven across the screen, kind of like a vertical linearity issue only sideways. (Probably a cap in the Horiz section but it's not bad enough to delve into at this point. More annoying is the AGC noise I get when I hook it to any DVD player I can't seem to adjust it out to get rid of it completely. It does this cycling buzz that lasts about 5 seconds like it is having issues decoding around the dvd's built in copy protection.
the one from 1976 I picked up in a second hand store for 3 bucks and worked right away. The color bleeds like crazy. the higher you turn the color, the dimmer the picture gets. I tried my best to do a basic Purity setup and got it to where it has a decent picture. The red color seem to be where the issue is. the more intense the red the dimmer the picture gets. The red seems to drive the bottom of the screen more than the top. the top of the screen seems a bit darker than the bottom so maybe the yoke is in or out too far? I was hoping to get a service manual before I go too deep into this one as the picture tube seems very strong and when I adjust it out, produces a nice sharp picture.
Like all porta potties, it has Just Awful Dark and bright contrast issues as you dad mentioned Indication little or no DC restoration. If anyone has a Schematic or Even just a tube listing (Neither of mine seems tohave that) I would love to have it.
I brought back a re-branded GE H4 chassis PB re-brand set from SC. The set it NEW old stock, the tubes and crt test as such. After fixing a few whisker shorted pots its working.
The picture quality SUCKS though. I have heard these were not know for their picture quality...but, out of the box new this crappy. Its a full color picture its just overall poor.
Is this all I can expect?
ctc17 12-14-2010, 12:37 PM More annoying is the AGC noise I get when I hook it to any DVD player I can't seem to adjust it out to get rid of it completely. It does this cycling buzz that lasts about 5 seconds like it is having issues decoding around the dvd's built in copy protection. .
Happens on most all vintage sets, get a box called video stabilizer and it removes most of the macrovision trash and eliminates the buzzing and lines at the top.
I would look at the high voltage while increasing the color on the other set. I bet its dropping and thats whats causing your dim issue. Weak horizontal output tube or something.
They just dont seem to be very good quality. It seems GE made sets as cheaply as they possibly could. Every one I have worked on has left me in ah of cut corner engineering. The porta color is a cool set, but more of a conversation piece. I have 3 of them now and the main issue was whisker shorted pots, mainly the agc pot shorts internally.
btw...welcome to the forum..:banana:
emmjay_1998 12-14-2010, 04:31 PM Happens on most all vintage sets, get a box called video stabilizer and it removes most of the macrovision trash and eliminates the buzzing and lines at the top.
I would look at the high voltage while increasing the color on the other set. I bet its dropping and thats whats causing your dim issue. Weak horizontal output tube or something.
They just dont seem to be very good quality. It seems GE made sets as cheaply as they possibly could. Every one I have worked on has left me in ah of cut corner engineering. The porta color is a cool set, but more of a conversation piece. I have 3 of them now and the main issue was whisker shorted pots, mainly the agc pot shorts internally.
btw...welcome to the forum..:banana:
Thanks So Much Glad to be here. Hard to get any good info on vintage tv's I'll definitely check the voltage level the next time I open her up. BTW who makes a good video stabilizer?
ctc17 12-14-2010, 04:48 PM I have this one and am happy with it for the price. http://www.checkhere22.com/stabilizer/
This runs in the composite video line after the dvd before the rf modulator so your dvd payer has an rf out your going to need to buy a separate rf modulator or use a vcr etc
bgadow 12-16-2010, 02:16 PM Something to check-next to the horizontal output tube you will find a largish white capacitor, probably an Elmenco, one of those tubular caps with a ceramic shell. These tend to either fall apart or blow apart. I had one fail when I was watching the set and it kept playing but with a lot less brightness, as well as some other defects in the picture. I would replace it as a precaution; might even make things look better.
etype2 12-18-2010, 02:56 PM I remember well, the poor image quality of brand new GE Portacolors in 1967 or 68 in stores. Every time I saw one displayed, the same thing, course pixel structure and very dim, poor color.
zenith2134 12-18-2010, 04:04 PM Put a NOS 11" crt in my '66 port-a-color and it still looked pretty mediocre. Got it tuned up near perfect, and that helped, but still it isn't a world-class performer or nothin'...
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