Hi All,
I have a 1964 Magnavox roundie color stereo theatre, as mentioned in a previous thread. Would anyone here be able to guide me through the convergence procedure? Any help would be greatly appreciated.

Thanks,
Frank

You could aquire a copy of the SAMS for this set. Seems I remember that there is a fairly detailed set-up there...

Have you got a dot-bar generator? A degaussing coil? A plastic coil adjustment 'diddle-stick?'

Sure, no sweat. Send me a PM and I'll walk you through it. In addition to what holmesuser01 listed you need a mirror to put in front of the set so you can set the purity, etc. I found early in life that Sams convergence procedures can drive you bonkers.

If you dont have the dot-bar gen, degaussing ring etc, you can borrow mine, i am on the south shore too. enjoy. Bruce

Here's a quickie; assuming you have the white balance & purity in decent adjustment (OK black & white picture except for colored ghosts):

If you don't have a color bar/pattern generator, connect a cable or SAT to the set, and receive the program guide or something steady with white lettering.

Turn the color all the way down, and adjust brightness & contrast for visible but not blurry white characters.

Looking at the center of the screen, use the 3 slide magnets on the neck of the tube, to converge the 3 guns (also the blue lateral magnet to move the blue straight left to right). The blue slide magnet only moves it up & down). Don't mess with the purity rings (two thin metal tabs on the neck of the tube) at this time.

Once you have the general middle of the screen converged, then you can touch up the edges with the 9 controls and 3 coils on the convergence chassis. I think on the Magnavox, you can flip it up and mount it so you can reach all from the front, as trying to do the fine convergence in a mirror sucks eggs.

Feel free to repeat the whole thing a few times, as practice makes perfect ;-)

***Beware of high boost voltage on the terminals of those slide magnets, if exposed. I don't think Magnavox has it exposed, but it's good practice to assume it does...

Charles

After first determining that convergence is roughly correct, checking purity is really the biggie. You don't want to do a full convergence procedure without first having good purity, because purity adjustments interact a bit with convergence. On Maggie roundies, purity is done the same as the RCA procedure. And it's done with the red screen.

With the set out from the wall but in the same compass position, turn the blue and green screens all the way down and the red screen all the way up.
Give the set a thorough degaussing.
The red screen should show perfect purity. If it doesn't, loosen the yoke clamp and slide the yoke as far back as it will go.
Use the purity rings to center the red blob as near center as possible.

Slide the yoke forward slowly, watching for the 'sweet spot' where best purity occurs. It will be with the yoke roughly 1/4" to 1/2" shy of fully seating against the CRT bell. Clamp the yoke at that spot (while being sure to level it also).
This point may or may not be covered in Sams, but it is the RCA factory procedure. (It applies to 25" rectangulars also, but with the yoke's 'sweet spot' 1/8" to 1/4" short of fully seated.)
As the previous poster mentioned, feel free to repeat as practice makes perfect. :tresbon:
Bill(oc)

Hi All,

Thanks for all the advice with the convergence procedure, and setting up purity. I'm going to be out of town next week, but once I get back, I'll try to tackle this.:thmbsp:

besides the nice red blob in the middle, you should note a trio of blue and green blobs around it. Purity setup can make a dull weak color set come alive. I had a zenith avanti CC2 that was just a bit out of purity, a minor tweek of the purity rings made a HUGE difference in how nice the colors came in (and as noted, now I need to go back and touch up the convergence).

You also want the vert height and lin setup before convergence as changes there can mess it up as well.

On older sets you may want to spray some solvent (rust buster, WD40) in to the coils and let it soak in. You sure do not want to strip or break the cores. Another tip is to place a metal allen wrench into the core but DO NOT TRY TO TURN IT. Then take a soldering gun and apply heat to the wrench. Let the heat travel into the core. Let it cool, spray more solvent and repeat with the heat. Convergence on these sets took about 10 to 15 minutes once you have the hang of it. After the center is done, red and green vertical and horiz. Then left and right.Then blue on top of that vertically and horiz followed by blue left and right. If something did not move, change the diode block.

In case you would like to see a picture of the screen during a purity adjustment.....
http://i1095.photobucket.com/albums/i469/ElectronicMemory/Capture11.png

One tip I learned on these was to double check purity with all blue and all green also. Set it up with the red like the guys have already said, but sometimes a small edge imperfection will show up on one of the other colors but not red, and you can try to touch up the purity on that. Then go back to all red and make sure that didn't get screwed up. Final rule is if you have to choose one color to have better purity, make it the red. Seems like errors in red show up a lot more than green or blue

Hi All,

Today, Bruce came out and set up the purity and convergence on the Magnavox. The set came back to life like you all said it would!:beerchug: Bruce is a great person; he explained everything to me as he was working on the set, and has a great wealth of knowledge. I'm really appreciative of everyone's help, and I'd expecially like to give out a big 'Thank You' to Bruce for coming out and showing me how great these old sets can operate when set up properly.:D

Frank.

Hey Frank, Youre very welcome and it was a pleasure to do it. hope you enjoy that set for many years, post some pix when you get a chance. That Sylvania crt is amazing.