Re: Which university produces good analog EEs?

But does modern design practice use vacuum tube logic circuits still?

Ah, now it registered ;-)

You've got mail.

Ah, but don't you recall that thread Win started a while ago? Didn't his solution involve a tube? ;-)

Tim

-- Deep Fryer: A very philosophical monk. Website @

The HV switch? I think he went the white-knuckle route using a FET stack. A ballast triode would probably have been the perfect fit. Problem is, they don't make'em no more :-(

Joerg snipped-for-privacy@removethispacbell.net posted to sci.electronics.design:

Ah but they do. High voltage (over 1000 V) vacuum tubes still popular. I think Win even used a tube solution for a 10kV ramp generator recently.

That was the one.

Tim

-- Deep Fryer: A very philosophical monk. Website @

Who? There are some tube mfgs and probably the largest ones are Sovtek and Svetlana but there ain't much in HV tubes there. It's all audio because that is where the big bucks can be made.

IIRC he opted for a FET stack.

...and some really nice HF RF linear power amplifier devices.

Jim

Ok, yeah, of course you can still get some of the really big tubes. But those aren't practical and economical for a small HV circuit while the old TV ballast triode might have been.

Joerg snipped-for-privacy@removethispacbell.net posted to sci.electronics.design:

I am asking him.

Big tubes, CRTs and the like you can get from Western mfgs. But any regular tubes will be NOS.

Some of the HV stuff is still being made in small runs.

Cute trick: use an HV rectifier, like a 1B3, and control its filament voltage to make it an amplifier. I used to do that when I was a kid... flashlight battery, rheostat to filament (with long plastic shaft!), neon sign transformer, charging a bank of oil caps, with the loop closed manually. You could run the xenon flashtubes just below the point where they'd fire spontaneously.

Amazing I'm still alive.

John

One TV tech I worked with when I was 13 would reach into those old tube type color TV sets and grab the second anode lead, then touch someone. ONCE. Most people never got close to him again, after that.

Neat! I wonder what the achievable loop bandwidth would be ...

I guess many of us wonder about that. I remember dropping a tool into my