portacolor CRT replacement video

[Rod Beauvex]

I loved the totally flat "Anyway, that was a success" comment in the vid.

Does the bottom always have the circuit board exposed?

[DaveWM]

the cabinet back has a bottom part attached. when its completely put back together the bottom PCB is protected by a slotted cover. I have to work on the degauss switch, its not working reliably.

[zenith2134]

Mine was the same model. Had a lot of trouble setting proper purity and convergence, although , as documented here in pictures someplace, I got it damn close. That was a space-heater in terms of radiated heat but it was quite a reliable GE and made a charming picture. Also ran into a case of the tun whiskers on the AGC potentiometer causing a white raster, Blew it out with 600VDC capacitors

[DaveWM]

this set is using only one of the convergence dynamic coils, the horz ones. the vert coils are not in (green directly to ground). I will have to get a good cross hatch to do a better job of it. It does have some tunable issues (somewhat tunable, I can't completely correct with fine tuning).

It looks sorta like a delay line issue in the chroma, the chroma seems to be shifted to the right a bit. De tune (fine tuner) and it look better (and the chroma gets weaker but easy to up the color to compensate). If you tune it to near sound bars like most set would be tuned the chroma goes into overload, and the colors tend to separate, the green lagging the most to ther right (separate horizontally that is). I have heard of delay line problems, but I am not sure that would account for the tunable issue, except for if the chroma gain increase in the IF pass band would some how make the delay worse. Also do not under stand why the green would the most effected (shifted the most to the right).

It certainly not a big deal as just detuning gets you almost there. My plan is to sweep the IF and take a look at it, but will not make any adjustments until I get some time with my BK 415 on some other sets.

[DaveWM]

ok looking a bit closer with the color all the way down, I can see a tunable cost in the luma as well.