Just how bad can an Ion burn be?

[benman94]

I would be very leary of a Russian rebuilder. Look at the "quality" of Russian small signal tubes...

[Gleb]

Originally Posted by jr_tech

Do they do any rebuilds for customers outside of the country?

I think they could do, but safe shipping would be the main problem...

Originally Posted by benman94

Look at the "quality" of Russian small signal tubes...

And what's wrong with them? I've never bumped into any problems with Russian tubes, at least with vintage ones.
Anyway, they do provide a nice warranty, as well as use modern brand-new cathodes with 10000-hour lifetime.

P.S. If you'd like to discuss the quality, let's get started with a random example: 2A3 RCA vs 2S4S Svetlana

[benman94]

Originally Posted by Gleb

I think they could do, but safe shipping would be the main problem...



And what's wrong with them? I've never bumped into any problems with Russian tubes, at least with vintage ones.
Anyway, they do provide a nice warranty, as well as use modern brand-new cathodes with 10000-hour lifetime.

P.S. If you'd like to discuss the quality, let's get started with a random example: 2A3 RCA vs 2S4S Svetlana

I've had issues with Russian tubes, and they have a very low reputation among most audiophiles and antique radio restorers. Even the terrible Chinese tubes seem to be better. I'll wait for rebuilding to get off the ground at the ETF...

[Gleb]

Originally Posted by Tubejunke

The procedure I have always used is to set brightness to a mid level with the magnet in approximately the correct position (over the split/gap in the gun) and rotate for max brightness. Then move slightly back and forth again for max brightness

That works properly only if the magnet keeps its initial power. Howewer, Al-Ni-Co magnets are often degaussed from aging. A degaussed magnet seems to behave properly while aligning, i.e. it still provides some "max brightness" position, but this does not mean that the whole electron beam reaches the screen.

Originally Posted by bandersen

You're not going to cause ion burn by a misaligned trap but you can damage the gun elements with the electron beam

I have at least one reverse example with a bent-gun picture tube, but it could happen from a degaussed magnet as well.

Originally Posted by benman94

I've had issues with Russian tubes, and they have a very low reputation among most audiophiles and antique radio restorers

They just have to be well-chosen. There are some top-grade ones (Svetlana, MELZ - just look at the pictures I attached to the previous post), some normal "workhorses", and, as always, some crappy crap hurting the whole reputation. I'm guessing that I should write some sort of choose guide here.

[Zenith26kc20]

I have always tried to keep the ion trap with the set it came with. My highest hour is a Motorola with a 12lp4 (can't remember the chassis but I think it is either made in 1949 or 1950. Original tube as far as I can see. Good and clear, no burn and many(!) run hours! My TS-4J takes a bit to get bright but looks good after about 10 minutes.
As for Russian tubes, my worst fire breather is a Audio Research D-150 (1976). I use Svetlana 6550B types in regulator and output. This critter will kill a set of GE welded plates in about 2000 hours. I've had the Svetlana going on 3000 hours (close to needing a change according to ARC) but no sparks/blown $11.00 dollar fuses in a long time. I have heard the "C" types are better but I'll wait till it no longer meets specs to change anything. I also have the Svet "B" types in my D-115. The D-115 laughs at Chinese tubes! Then eats them!