Resistor or jumper at hv rectifer socket: Zenith 25mc30

[Tubejunke]

Originally Posted by dieseljeep

You mean to say, they don't know Thevenin and Norton's theorem either?
I'd have to get back to the books! It's been years.

No they don't. Ohm's law would be the only thing that a modern JR college curriculum would include and perhaps Kirchoff's Law; and that would be very limited. I don't mean to put the younger techs down for what they were never taught. I just think that it's a shame that what was once a respectable discipline that was pretty darned involved and anchored in the roots of the science of electricity/electronics has like so many things been dumbed down so, yet the students attain the same credential as students of old who I feel had to work harder to get what they got.

I have been told that my mindset on this suggests that I or anyone else should attend a university. I say that's wrong because you are not going to perhaps get through a high school trades course and then get a couple of years of college under your belt to find yourself beginning the theories and the math to prove them which is the foundation for all of what we do when completing your Bachelor degree which at that point would be electrical engineering. I guess there are better and worse JR college programs and a lot of what I remember was a bit of a joke. And that's back when it was a lot harder than today.

I remember an exam question on the definition of voltage. The correct written answer was "a force." Sure, it's a force. So was a big part of Star Wars! Just an example. I am told now that they have almost completely converted the focus to what is known a Mechatronics. Basically automation, so some factory can get you to be the grease monkey and the electronics tech. The I.T. guy gets an office! So the college tossed a truckload of oscilloscopes, function generators, Variacs and other great tools in the dumpster one day. You couldn't even buy them as they were government property to be destroyed. I won't bother going into grading most tests based on the lowest grade so basically nobody flunks out. Money!!!

[Tubejunke]

OK folks, as promised; here is where I stand. I didn't want to post pics until I had a decent color picture. I think I found and tested 10 6GH8 tubes before I found one even marginal one one of the two tests for that tube. The rest were LOW emissions. I have heard that the 6GH8s were lousy tubes and my B & K Dynajet 747B sure proves that. I notice that there are some common subs like 6U8 and 6EA8 that may work, but I had none on hand. Anyone every tried any other subs?

But as for the whole HV rectifier project; it looks like a wrap. Very stable and still using a slightly reduced line voltage I can maintain less than 200mA at the horizontal output's cathode. The fly seems to be running cooler than it was when I had the old socket and corona hiss. I absolutely love that silence and a cool fly.

I am really surprised at the generally good color picture with really no alignment. Not proper anyway. I did set the service switch and touch up the guns to get as good a white line as I could, but there really wasn't much to do there. Next comes the use of the same age RCA dot bar generator as up close there are obvious alignment issues. I think it will be stunning when I work those out.

Thanks again everyone for the help on this!

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