Hoffman 7M112 tabletop

[Phil Nelson]

Wow, that's interesting. I wonder if this could be a Rauland tube? I don't see any labeling on the base or what's visible of the neck.

The first time I tried the ion trap, I could clearly see the glow brighten or darken at various positions. (One practical drawback of this scheme is that the room needs to be nearly pitch black to see the green glow. I hadn't noticed it until I turned out the room lights in an effort to catch any glimmer on the screen.)

I don't have any hint of raster, or any sound of HV spooling up, although I'm not sure I can really hear that anymore.

I retried the set without the brightener, just for kicks, and guess what -- no green glow. I moved the ion trap around and suddenly there was a brilliant flash of green all the way around that tube element. Now there's no glow, with or without the brightener. So who knows, maybe that trace of green phosphor just made its last gasp, or for all I know there's a loose wire in the CRT cable.

Tomorrow I'll pull out the chassis and do some more sensible investigations, clean the tube pins & controls, etc. I'm wondering what sort of tuner this thing has, among other things.

Phil Nelson