Strange Valve Circuit - Redrawn for Clarity

I'm not. Perhaps I replied to you when it should have been another poster. My apologies.

An 8 element tube would be called an octode. A 7 element tube would be called a heptode.

This is a heptode:

Pentagrid converters are heptodes.

Here's a link to the document the original schematic came from:

It appears on page 46, even includes a layout. Same document that had that other weird circuit posted here a couple years ago, just a 4 stage version. Download and read at your own risk. (I suspect you already know about that doc...)

In series. It's supposed to be a RF amplifier, in this case with a terrible 120hz modulation due to lack of filtering. For its intended application that probably does not matter.

With 50K plate resistors, miller effect and stray capacitance will limit HF gain. But with four stages still might be fairly high.

My guess is 0.003uF

Possibly but more likely to avoid oscillation and limit the input/output to high frequencies.

Something like this...

.--------0.003u---> >--0.003u--*-->| MPF102 2N3819 etc | |---*---. 470K | | | 2.2K 0.1u _|_ _|_ _|_ ground

For best results vary the 2.2K for about 5V on the bottom of the 4.7K. String up as many stages as you want. YMMV.

yes

Basic mistakes happen to unblind people too. We all know this.

NT

It's basically an RFI generator. It picks up rf etc, amplifies & distorts it & chucks it back out. I forget whether it was thought to kill tumours or insects.

NT

Aha, you avoided including much critical information.

The input to the circuit is a photograph print: a piece of paper. The wire connects to a photograph of a plant, or of a farmer's field. The tube amp is supposed to kill insects in the field using magic mental power called Psionics or Radionics. It's the same as John Campbell's articles, the "Hieronymus Device," featured in 1950s magazine Analog SF.

See:

It's the UKACO DEVICE, see the original page from your large pdf

Note that Figure 1 looks like a patent drawing.

Extremely important, No. 17, the tree. The tree is infested with caterpillars. Numbers 1,2,3 are a photo of the tree, painted with pesticide. Yes, the device works by magic, same as Ouija boards and dowsing rods.

Heh, guessed right the first time!

Nope, it wasn't a ground. It was a photograph!