View Full Version : Veg-o-matic needs help!


veg-o-matic
05-09-2004, 09:34 PM
But we all knew that, right?
Here's the deal; remember thatn NOS Dumont that Doug found at the beginning of the year? Well, I just bought it from captainmoody and it arrived yesterday. I was hoping it would be plug-n-play like the roundie I got from Doug, but no such luck. I'm hoping the problems will be easily solved.
First of all, I think it needs to be converged. The color in the center of the screen looks okay, but as you get to the top and the bottom, you can see individual red, green, and blue outlines. Is there any way I can converge this without A) some expensive piece of equipment and B) knowing what I'm doing? There's a service switch on the back that turns the picture into a single horizontal line. Is this of any use?
And speaking of switches on the back, this set has like a gazillion knobs and buttons and things, some of which aren't even labeled! What the heck is "kine bias"? The switch has three positions. Green drive? Blue drive? There's no red drive. Then we got the Red/Blue/Green Screen knobs. Haven't touched 'em, as I'm afraid I'll mess up something really bad. I think I can figure out "color killer", but there's another knob right above it that's unmarked. Not to mention the other unmarked knob that's next to it. Add some little knobby thing on the end of the picture tube, and it's no wonder I'm confused!
Second, the sound is really terrible. Sounds like interference and static and just general awfulness. Muddy might be the term.
The last big problem is the vertical linearity is way off.
What are the chances that any or all of these problems can be fixed easily, like with adjustments or replacing tubes or something? Anyone got the schematic for it? I'm thinking that might explain the Mystery Knobs. The best I can figure is that it's model STAMxxxx. Can't figure out the last four digits. It's chassis # 55T01. Doug: might you still have the paperwork that came with the set?
I throw myself on the mercy of those of you who know what you're doing! If you've read any of my previous posts, you'll know that (well, besides being whiny and lame-brained!) I'm pretty ham-handed when it comes to electronics. I like watching 'em, but poking around inside just makes me nervous. P.S. I've already busted the on/off switch, but I think I got it fixed again.
So you see what you're dealing with...
Anyway, thanks in advance for the help! Once I get the thing running halfway decent, I'll post a picture.

Chad Hauris
05-10-2004, 06:22 AM
The service switch is NOT for setting convergence...if you adjust the convergence in the service position, it will be off. The service switch is for setting your color temperature...this allows you to balance the red/green/blue proportions.

To set it up--put service switch in service. Adjust red, green, blue screen controls until each color line is barely visible on screen.

Kine bias=kinescope (picture tube) bias, it sets the range of the brightness control. You adjust the kine bias up if, when you are setting up the screen controls, you have the screens maxed out and one or more color lines are not visible.

Green and blue drive are to set up the "foreground" color balance of the picture. Red is the weakest gun in the CRT so it is usually always run full power...you can then adjust the green and blue to match it.

Bad sound could be a misadusted quadrature coil, this is a coil in a metal can near the sound detector tube. It may be good to refer to service data to make sure you get the right coil.

Adjust the vertical height/linearity before setting convergence: misadjustment will mess up convergence.

You can do convergence using a menu from a DVD or a channel like Home Shopping network that has static text on the screen. Turn the color control down to produce a b/w picture. Adjust the three magnets on the convergence coils and the blue lateral adjustment (knob on back of CRT neck) to converge the text in the center of the screen. Use the 12 potentiometers/coils to work the edges.

veg-o-matic
05-14-2004, 09:25 AM
Well, I got started.
Chad, thanks for the assistance. I attempted to do some static convergence last night and it sort of worked. I neglected to refer to your instructions and so did it with the color up instead of down. Still, it looks a little better; "regular" TV still looks messed up, but Bugs Bunny looked pretty good!
The edges (top and bottom at least) are still way off. Just for the hell of it, I started messing with the knobs on the convergence board and it didn't seem to do anything at all. Hmmm.
I got the SAMS for the set but it's less than helpful. Apparently, there's some vertical linearity control (R113), but damned if I can find it. Due to a lack of knowledge, I sorta assumed that the R meant "resistor", but all the knobs are listed as R-something, so what do I know? I messed with one of the unlabeled knobs and it turns out to have something to do with vertical hold--sort of makes the picture roll then turns it into a narrow white line.
Sound is still icky. It starts off not too bad but seems to get worse as the set runs. Then is sort of gets a little better, then worse. I managed to find the quadrature coil. If memory serves, there's something in the SAMS about adjusting it (and maybe some others) but I'm not sure how to go about it. What kind of tool do I use?
Is this one of those situations where I should buy some piece of test equipment to get the job done? I'd really like to get the set going well enough to use as I already have some dough invested in it.
Thanks again for helping!
Bob (who hasn't fried himself yet, but it's probably imminent...)

wa2ise
05-14-2004, 07:28 PM
Before messing with the convergence, get the vertical working better. The usual suspects: Weak vertical output tube, wax caps, and maybe some off value resistors. Pretty much the same as in B&W sets.

andy
05-15-2004, 10:50 AM
Yes, you won't be able to get good convergence until the vertical is working properly and adjusted properly.

veg-o-matic
05-15-2004, 09:00 PM
Well, progress of a sort.
Captainmoody suggested I sub the speaker, as the NOS Emerson that was found at the same time had a speaker warped from moisture. Sure enough, she sounds much better now!
Okay, got that problem licked, now it's time to move on. Anyone got any idea how I would adjust the vertical linearity? As I was watching more Bugs Bunny cartoons, I noticed that the "rabbit hole" in the opening credits is almost shaped like an upside-down rounded triangle. Could this be keystoning, even though the picture fills the screen and looks normal in the middle? I will try posting a picture, but for now, my camera seems to have crapped out on me.