Funky hybrid regulator

When transistors were just becoming affordable, there was a last-gasp burst of effort to save the tube industry. There were compactrons, nuvistors, cold-cathode tubes, tubes that would run at 12 volt B+.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

The 6AC10 is an adorable lil tube, mine's Raytheon-branded but made in Japan:

I don't really have a use for the "funky regulator" but I like the idea of using an optocoupler to provide drive for the pass element of a HV regulator, avoiding high voltage transistors or having to float op amps and such.

I have one "tube bin" with some random stuff like the 6AC10 and some 12 volt tubes in it, even a Strobotron...at some point I inherited a couple packs of 0B2 gas diodes.

Amazon/eBay sell these little boost modules for tube experimenters with a HV output and a 6.3 volt output maybe good for an amp or so, they really hate driving a gas tube directly as a load and the 0B2 flickers like a neon Christmas candle, some nice noise/chaos on the 'scope too:

Just a heads-up for those who use imgur. For the last 3 months imgur has not been available to those in the UK:

Our loss, but rather frustrating. Please use dropbox, imgbb, or something available to us if you want any comment from here in the UK.

It was a very long time before the performance of transistors caught up with Nuvistors. In high radiation and EMP situations, I don't think they have yet.

Before transistors began to compete, valves for car radios used +12 on the anodes but they also used either 0v on the first grids to assist the electrons out of the cathode or +12v to drag them out.

In outer space, where the vacuum is 'perfect' and solar radiation could be directed onto a sheet cathode, new types of valve might begin to make sense.

I have some Arcturus Blues, some proiximity fuze tubes, an old radar t/r thing (I think), some acorns, a Krytron, a couple of giant transmitting tubes, lots of CRTs, some pretty PMTs.

Just pretty glass. I don't plan to use any of them.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Philo Farnsworth was a cool guy. He invented the image dissector tube, the Farnsworth Fusor, and did some interesting multipactor work.

The perfect vacuum in space has some hazards to power RF circuits that you don't get here.

I think he invented the microchannel plate too.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Seems unlikely.

The original application was for night vision googles. Cambridge Instruments used them as electron multipliers in their electron beam microfabricators. They had to be replaced every six months, but that was tolerable with a million dollar machine.

This is what google says:

AI Overview The concept of the continuous channel electron multiplier, or continuous dynode, was first proposed by American physicist Philo T. Farnsworth in 1930, with early prototypes and active development occurring in the 1960s, particularly with work by Russian scientists like I. Pesyatsky and later commercialized into microchannel plates (MCPs). Key Contributions:

Philo T. Farnsworth (1930s): Proposed the fundamental idea of using a continuous, hollow resistor coated with secondary-emissive material to amplify electrons.

I. Pesyatsky (1940s): Created one of the first working prototypes of the microchannel plate (MCP) structure.

Philo also achieved nuclear fusion around 1965.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

He clearly didn't reduce the idea to practice,

Rather ignoring the commercial realities.

But not in a way that could be used to produce energy.

It is apparently useful as a neutron source.