RCA ColorTrak FMR620WR (CTC-130A) From 1986

[colectorad]

After creating a 4:3 test pattern DVD from here, I proceeded to make adjustments.

I did not cut the zip tie from the convergence magnet. It was loose enough to slide off and proved useful for clamping down the magnet after the packaging tape was removed.

The static convergence was not originally calibrated. Instead, they chose to generically set the seam of the magnet to the 12 o'clock position on the yoke assembly, probably to speed up the assembly process. I found it looked best between the 7 & 8 o'clock positions:



^The upper right corner is still bad. No amount of yoke adjustment would improve it. I'll need to make a v magnet at the very least.

Then, I adjusted the green bias:



Note the powdery blue distortion at the upper left on the white and yellow, it's not dust and it's not on the outside of the CRT:



While the static convergence adjustment did greatly improve the horizontal centering, the vertical centering is still off:



^The yoke doesn't go up any further. It needs to be adjusted electronically with modification. I just need to know where to install a variable resistor, as well as its' ohm range and any supplementary components.

[zeno]

Looks like the purity is off now. Try with green screen
only. Keep the brightness down or it can throw things off.
Then try to correct with magnets. If the whole side is off yoke needs
slide in or out. Unfortunately you may not be able to get
it perfect without a ring set.

73 Zeno