Flyback temperature

[drussell]

Originally Posted by Electronic M

One thing that might loosen your slug is (provided the wire is thick enough to stand the current) with the set turned off connect a D cell battery across the coil and let it warm up until the slug loosens up, then remove the battery and the slug and then quickly try to clean any wax or other gunk from the slug and coil threads before it cools.....

Originally Posted by Tubejunke

I still may try this as I would like an intact slug in my new coil, but the other half of me says leave it alone; for now at least.
...
As far as heating it up with a battery goes I am afraid that I may short the windings by burning away the laminate. At least I had adjusted it before it froze up and being new I fear that the only way that it could freeze up was that it was somehow overheated and the insulation that melted is holding it in place. As long as it isn't shorted I am ok and I have the spec sheet resistance values.

Can't you just lightly warm it up with a hair drier or heat gun wafted around the area or something so it's less likely to harm a winding trying to use it as a heating element?

[Tubejunke]

Originally Posted by drussell

Can't you just lightly warm it up with a hair drier or heat gun wafted around the area or something so it's less likely to harm a winding trying to use it as a heating element?

That is exactly what I was thinking. If a hair dryer will do it, that would be the thing to use. A heat gun puts out an incredible amount of heat and I fear that it would melt the spool which takes me all the way back to my original hunt for one of these. My spool had deteriorated to dust and the winding was just dangling. That may have been OK really as the slug was in there and the bulk of the winding was just as it would be with the spool, but the dangling winding's weight caused some separation of the winding and I was advised that just that would be enough to render the part bad.

I should have (back then) checked the H.O. cathode current while moving the winding around a bit to see what it would do.

[old_coot88]

OOPs! Duplicate post.

[old_coot88]

If the K current is holding reliably at 200ma., i would be inclined to not fuss with the eff. coil any more (despite not having been able to find the 'dip' earlier).
Back in the day, 210ma. when 'on dip' was considered nominal.
200 would have been all the better.

[Tubejunke]

Originally Posted by old_coot88

Back in the day, 210ma. when 'on dip' was considered nominal.
200 would have been all the better.

Finally had some time to sort things out a bit better and made some improvement. First, the set is holding a steady 210mA, or did for at least an hour. The corona arc is all but gone, but you can sometimes hear it hiss just a bit, but not showing up on the screen. I'm real happy with that, but I would like to have it completely clear of any corona discharge. Possibly some more extended play time will work that out.

Either earlier here and/or on another related thread I mentioned complete loss of color. I have read that 6GH8 tubes were troublesome for whatever reason. That must have been an understatement as I remember checking the single tube in my set's compliment (which acts as the chroma reference oscillator) a while back and it checked OK, but I can't remember if that test was done on my cheaper Accurate Instruments tester or on my Hickok 6000A.

Either way it goes, I pulled the tube tonight and plugged it into my Hickok and the tube was really weak (in the red) on both the triode and the pentode tests. Luckily I had about 8 of them in my used collection and of them all only one came up to the question mark symbol between the bad and good scale on both tests. I thought that it was a bit odd that most of the tubes I had were testing in a very similar range which fell within that ever present "diodes OK" area, I tossed any that were below that point until perhaps I just try them in the set.

The one that was dead in the middle (question mark) got put in the set and BAM color at long last! That's been a long time coming as it's was the first thing to go wrong with the set. Now if I can get that ugly white line (Barkhausen?) out of the left side of the picture and do some convergence work I might be one of those lucky guys who have Zenith color sets that they don't have to post about because they work as is! LOL! I'll have to find me a CTC something to keep me busy if this goes right. I really don't have time anymore for a proper recap if repair is all that is needed. We will see.....