did a quick test, maybe 2ma drop but that could be anything. Of course I don't even know if the convergence board is functional so just plugging it in really proves nothing at this point.

the horz osc has an annoying problem with not alway starting, I can see the current spiking, a quick fiddle with the horz hold coil and it starts right up. I hope its just a tube issue. I could not see any loose wires on the hold control.

I will go back and reflow everything on the horz board if the new tube does not do the trick. It seems like it would have to osc, unless something is biasing it off on startup (gassy/weak).

another tip, if the horz hold is a bit touchy (it was much better after the tube fix, about 3/4 turn range vs 1/8 range, it was still not right.

I checked the resistor across the horz hold coil, a 68k, I assume it damps out the coil, making it less peaky, so had to remove it from the circuit to check, sure enough 381k, so that one got replaced. While I was there I checked a 270k power resistor, it was about 330k, but it was a 5% so I changed it as well. two changes were noted:

MUCH easier to set hold you can turn it several times and still stay locked in.

Drive bar was gone even a the lowest drive setting. (before a drive bar was present but could be dialed out with the drive control pot). HOtube current is up just a tad to about 175ma with drive set to max.

for fun I am going to replace that drifted power resistor and see I can get the drive bar back.

I am pretty sure the 68k damping resistor will account for the better hold control, but maybe it also altered the drive wave form (and subsequent need to adjust out the drive bar).

I little more work done lately. I removed the tuner to clean it, as I was getting some problems that seemed to be due to the tuner.

1st order of bus was to get the tubes out and make sure the pins were clean, both were stuck, one really badly stuck, but I got them out and cleaned up the socket and pins.

2nd I pulled the cover and cleaned up the wafers, I have seen worse but it still had some dirt on there. I use a contact cleaner and q tips, don't like hosing it with spray, and risking getting spray where it does not belong.

3rd dunked the VERY rusty cover into some muriatic acid. in just a few min all the rust was gone. neutralized in some base water (baking soda) rinsed, dried, oiled.

Replaced the AGC cap that was on the tuner, and then hooked it all back up, no more touchiness. I should have installed some quick disconnects, but no big deal.

I think its pretty much done so I think I will take it off the bench and clean up the mess so I can start thinking about the cabinet.

something of note, while looking for any reason for "soft" pic, I remembered some discussion about intentionally skewing the IF curve upward on the high side to improve video response (think it was a CTC-5 iirc). Just for the heck off it I diddled the 47.25 trap (I know I know should not diddle the IF unless prepared to do a full on IF alignment). anyway a very small adj while on some still frame text allowed me to remove a LOT of smear. I plan to do a full alignment at some time in the future, but just wanted to make note of it. Prob a 1/5 turn at most of that trap.

I may try swapping in some new IF tubes as well just to see the effect.

still coming along, had a convergence issue, made a video of the fix

http://www.youtube.com/watch?v=2wYn3xLrZj0

looks good!those sets were a bear to converge.this one is almost perfect

nearly done

http://www.youtube.com/watch?v=lJUeUH8bTW4

video is outstanding.picture is beautiful.another saved and dave,you rocked this on out!

It's looking great, Dave. Makes me want to take another stab at the convergence on mine. And the color looks superb.

When you say that you are leaving the flyback cover off, do you mean that you are leaving the entire HV enclosure off? My flyback gets pretty warm too...

-Clark

yep leaving the whole cover off. Make it a LOT easier to check temps, replace tubes (esp the 3A3, its easy to break that plastic bucket, with the cover off you can hold the metal part down and not stress the plastic bits after discharging the CRT of course).

I know about the concerns for X rays and Fire, both of which are supposed to be contained by the full metal box, but its my set and I understand about the dangers. I am not too concerned about X rays since its got a metal cabinet and I don't plan to stand behind it in operation.

I could mount a fan to the fly cover box, and may end up doing that for cooling but it still is a pain to replace the 3A3 with the box in place.

This is why I titled the video "nearly done" :yes:

the convergence was much easier after I got that horz coil replaced. Its key to make sure all the controls are working as they should. I ended up replacing some leaking or lossy caps in the board, left the orig Se diode pack alone, oh and replaced a couple crunchy pots on that board as well.

Thanks for the info. I'm not too worried about my flyback since I don't run the set for more than two hours or so at a time.

The convergence board is the only part of set that I haven't recapped, so I think I'll start there. A couple of the pots are kind of questionable, too. The convergence is only off at the edges so I haven't been very motivated to mess with it.

Nice solution for the back.

-Clark