When did CRT technology advance to no convergence required?

[Phototone]

I was curious as to when Television CRT technology advanced to where there was no need for delicate and time-consuming convergence in the home? Was it the in-line guns? I have an original GE portacolor that just has the convergence magnets on the tube. I am assuming that was the beginning of the end of the myriad array of convergence pots and coils.

[John Marinello]

Actually, the newer sets had built-in pattern generators, and were converged via the remote control. The user would enter a set-up code, then you were able to move a cursor through the crosshatch on the screen with the remote. You were then able to tweak each color in a relatively small area.

[zeno]

Thats a poser. First in lines still had electronic adjustments
& would often need touching up but there were less adjustments.
I would say from abt 1980 on convergence & purity adjustments became
fairly permanent. Changing the jug or yoke was pretty much
the only time it was an issue. Many sets both US & Jap used
the RCA bonded (glued on) yoke CRT's. They also had a tape like magnet
for conv & purity so everything was factory set. Personally I
always liked the delta guns for set-up, after you do a few its
fast work to do it. The whole process made sense but I never
got the hang of in-lines, just messed with them & they would
suddenly fall into place.

73 Zeno

[Jon A.]

Just took a peek in my 1982 RCA through the vents with a flashlight. I knew for a little bit now that it has yoke wedges, but it has the tape-like magnet held on with a zip tie. The 1989 Panasonic I had however had wedges and adjustable magnets. Badly scratched screen on the latter.

[Username1]

Well I never knew a set that had built in pattern generators, The only set I have seen advertised to have it was Heath Kit Later GR series tv kits.... I would like to know which sets have built in gens, I know projection sets have them, I mean 30" or less direct view tubes... Do they have them...?

All color CRT sets had convergence adjustments. Newer sets have less circuitry involved in the process.... Old delta tubes had many coils and capacitors and many adjustments both mechanical, and electronic involved, each with tolerances that could allow it go go out of wack. Also the fact that the yoke assembly and convergence magnets were quite heavy meant that a slight bump would easily set those weighty objects into movement.

Newer sets don't have complex convergence circuitry with individual components that go out of tolerance. The light weight magnets are often bonded with some type of glue to the tube. Yokes are often also glued, and as stated have rubber wedges to keep them from moving during any movement.

Convergence is an art, one in which you need to follow steps, and also often jump around those steps as you see that you are doing too much work to get one part of the tube to line up, while another part is going out of convergence....

The inline guns require different steps, and you have to disconnect from delta's completely to follow a different set of steps for the inline's. And the inline guns are capable of much more perfect convergence than the delta's, even if anyone feels the process is more difficult, or less intuitive. They are by and large a better tube, built with better and more controlled tolerances, and produce a more sharp picture on average than the same number of delta's on average. Part of the reason field adjustments of convergence on inline tube is not very common.

Proper picture tube alignment ends with convergence alignment, often people here take a wack at convergence while other problems are not yet solved.

And you have to know yourself as well, I have found that the dots are much more harder to work with than the tic-tac-toe cross hatch pattern, so I don't use the dots at all, even if called for.

[Jon A.]

Originally Posted by John Marinello

Actually, the newer sets had built-in pattern generators, and were converged via the remote control. The user would enter a set-up code, then you were able to move a cursor through the crosshatch on the screen with the remote. You were then able to tweak each color in a relatively small area.

Interesting. Do these built-in generators produce anything other than the crosshatch pattern?

[zeno]

Originally Posted by KV-1926R

Interesting. Do these built-in generators produce anything other than the crosshatch pattern?

The only CRT sets I remember were Heathkits with it
built in. Its by no means a customer ajustment. Hard enuf to
explain the other controls to some. Many projo sets had
a crosshatch or just a + for the customer to use or an
automatic set-up like Hitachi.

73 Zeno

[John Marinello]

TV Service Codes:

http://www.repairfaq.org/samnew/tvfaq/tvadjlost.htm