• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

371B Thoriated Tungsten Diode

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I picked up a half dozen of these at a local estate sale that I would love to use. There are a few things I need to know that isn't mentioned in the datasheet.

1. Can I use capacitor or choke input?

2. Voltage drop

3. If capacitor input is ok, then max capacitance

If anyone has used these please let me know
 
That's a 50W filament. :eek: 100W of filament for full-wave rectification. :eek::eek:

The characteristic curve is very straight. It's the most resistor-like diode I have seen.

The peak anode current and the characteristic curves tell you what you need to know to answer all of your questions. You'll have to work through the math, but there are probably plenty of resources on the web to walk you through it.
 
I picked up a half dozen of these at a local estate sale that I would love to use. There are a few things I need to know that isn't mentioned in the datasheet.
Well, they te :)

1. Can I use capacitor or choke input?
Both.
2. Voltage drop
220V :eek: at 500mA , 460V :eek::eek: at 1.5A

Why so much voltage drop?
Well these are 25KV rectifiers, not your average cup of tea, so plate and cathode are well separated, not meant for Home Hi Fi and such.
Sorry.

3. If capacitor input is ok, then max capacitance
Not sure, but these are Industrial/Scientific/Military use tubes.

If anyone has used these please let me know
Maybe the guy who designed the B52 bomber radar or somebody with similar experience did, doubt us mere mortals have any.

EDIT: manufacturer claims to be part of "Nuclear Corporation of America"

´nuff said.

Being housed in an almost 9 inch long 2 inch diameter, top cap bottle, should have hinted at the BEAST it is.
 
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Tuff crowd, tuff crowd.

This tube is freaking cool looking, I don't care how hot the heaters are, I have the tubes, I got the sockets, I got plenty of volts to burn....Merica!

Pretty sure this tube ain't gonna emit x-rays at the voltage I am using it at.

Again, this tube looks badass and there is no mercury to worry about and I don't give a flying F if it's overkill, it needs to happen......even if it's in #45 monoblocks!
 
16kV is enough for soft x-rays.
Just light the filaments.
371B resistance is so high, you might get almost as much voltage out from a choke input filter, versus a very high capacitance input filter.

Instead, design an amplifier around transmitting triodes, tetrodes, pentodes, or beam power tubes that use thoriated filaments. There are plenty of those.
Some of them look great!

Some of them are almost Un-Obtanium (at least unless you have unlimited funds, and hire a detective to find out who has the last supply of them).
 
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So, my original plan was to use an Antek 360v 400va transformer and connect the windings in series for 720v and feed That into a bridge with two 371b and two 3b22 (3b22 plates connected in parallel) and then feed that into a choke and filter all that down to around 440v on the HY69 plates. Well, I just realized that in that configuration, the 371b are going to drop around 400v! OK, so going to put the 371s on the shelf and maybe do a bridge with four 3b22s (each paralleled into a single diode. I know this is excessive, but I got plenty of iron and I like the looks of weird vacuum diodes. I don't care if it's a waste, it's all gotta look cool sitting on the shelf (especially around halloween 🎃) at night🍻
 
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