Mighty Monarch of The Air

[miniman82]

Yep, it has air in it and the HV is causing it to ionize. Replace it, and get that HV all the way to the screen!

[vts1134]

Originally Posted by miniman82

Yep, it has air in it and the HV is causing it to ionize. Replace it, and get that HV all the way to the screen!

Got a new 1X2 today but noticed that the old 1X2 was a 1X2A and the new one is a 1X2B. The old tube is on the left and the new tube is on the right. Are these interchangeable?

Here is the new tube installed and waiting for a higher intellect to give it the green light.

[VintagePC]

Yep, they should be interchangeable.

Take a look at the letter code specifications - the trailing letters indicate features of the tube. A/B/C are revisions that are backwards compatible, and there are a few others like GT, M etc. indicating glass tube, metal, and some other things.

http://en.wikipedia.org/wiki/RETMA_tube_designation

[vts1134]

Fired the set up and got this.

Fired her down immediately. Is this normal? Just a burn off process or a symptom of another problem?

[old_coot88]

Holy mackrel. Possibly a dead short either in the doorknob cap or from the 1X2 filament winding to ground. oc

[vts1134]

Originally Posted by old_coot88

Holy mackrel. Possibly a dead short either in the doorknob cap or from the 1X2 filament winding to ground. oc

Maybe that's what was wrong with the problem with the other tube.

[VintagePC]

Originally Posted by vts1134

Fired the set up and got this.

Fired her down immediately. Is this normal? Just a burn off process or a symptom of another problem?

It can be a bit normal in POWER tubes... but you shouldn't see that in a rectifier. (Especially not that much- I assume that was a normal exposure.) Here's a 30 second exposure of the output tubes in my radio... and this was at a good volume for comparison.



To echo the other folks, look for a dead short. Keep the old 1X2 on hand-- it might still be good!

(EDIT: Ninja'd:

Originally Posted by vts1134

Maybe that's what was wrong with the problem with the other tube.

)

--> Though I do have to admit, that _is_ a very nice blue colour to see for real. Cameras don't do it justice.

[vts1134]

I'm sure glad my first project has had so many problems with it. Gives me more experience in what it's not supposed to look like on my future projects.

[VintagePC]

Honestly though, would you really have had as much fun, or appreciate the end result as much if you only had to replace a handful of caps?

For most of us nuts, the more challenging it is, the better - it's all that much more satisfying to wind your own coil and have it work than just drop in a generic replacement.