Fixing the alien translators mistake

Gaseous Regulator Tubes?

Cheers

An ancient form of zener diode.

They made a cool blue-purple glow.

After WWII, the US government sold surplus electronics by the ton, and all this stuff was dirt cheap, especially the things that ham radio operators didn't want. Some of it is still around. Plus, my uncle Sheldon had a shed full of electronics stuff he stole from the Army.

931As were used as random pulse noise sources in radar jammers, and there were tons of them on the surplus market. And lots of high-power xenon flashtubes and oil caps, probably runway lights. Fun stuff for a kid to play with.

I have a great affection for PMTs. They got me on an airplane for my first time, to state and national science fairs, a trip to Bell Labs, lunch with Walter Brattain, and a week as a guest of the US Navy in Charleston.

John

On a sunny day (Wed, 12 Oct 2011 08:32:30 -0700) it happened John Larkin wrote in :

Ah! look what I have:

500 V stabiliser tube, from an ancient radiation counter.

For a moment I thought 'VR' stood for 'Virtual Reality'.... :-)

I had a neighbour who did some electronics, and a kid at school had a father who build all sorts of tube things, I leaned some very basic stuff from him.

I like PMTs, although I encountered them much later in life, when working at the TV studios. They were used as detector (a huge one for red, one for green, and one for blue), in the flying spot film scanners. Not only beautiful pieces of glass, but also incredible gain. And fast.

blue),

I have a Philips XP2412 flat-face venitian-blind-dynode tube here on my bookshelf. It is a beautiful hunk of glass. The base wires are soldered to a round PC board with the divider resistors and an SMB connector. Ebay, I think.

I'll take some pics.

I got a tour of the Hamamatsu PMT facility once. It was like a super-clean high-tech hell, with gas flames on almost every workbench.

John

reasonable price seemed too dim.

DID have,

almost nothing from ebay

feedback in this project:

turns on it...

number of turns to get the next PMT voltage,

have them,

add some load to be able to make any measurements - 10M probe),

problem in a beautiful way,

but it will be in a metal box, so that does not matter that much.

I think you'll find that 1750V across the heat-shrink tubing to the LV drive winding won't last for long. Corona eats heat-shrink for lunch.

RL

On a sunny day (Wed, 12 Oct 2011 12:13:42 -0500) it happened legg wrote in :

reasonable price seemed too dim.

DID have,

almost nothing from ebay

feedback in this project:

turns on it...

number of turns to get the next PMT voltage,

have them,

add some load to be able to make any measurements

problem in a beautiful way,

cores, but it will be in a metal box, so that does not

Yes, possibly. I was thinking of winding some tape first for the production models. Not a big deal, tape width is just right too.

run

igh

And - even if it were true - what has that to do with the fact that you've posted URL's that Firefox can't do anything with?

"The requested URL /external_content/untrusted_dlcp/

was not found on this server. That=92s all we know."

Scarcely. It is kind of stupid not to take advantage of the occasional good idea that shows up in the peer-reviewed literature, but most of the electronic design stuff that gets published there is published by physicists and tends to be clumsy and old-fashioned - a feature of most of the electronics designed by physicists that you have drawn our attention to here.

For someone who claims experience with photomultiplier tubes, you have a funny idea of what might have been "clever".

As I mentioned about - presumably in a block of text which was too long to fit into your attention span - it's crucial to be able to regulate the voltage applied between the dynodes. Voltage regulator tubes aren't all that adjustable.

-- Bill Sloman, Nijmegen

[...]

They work fine here.

More likely something wrong with your setup, your PDF plugin perhaps to take a wild guess. Try disabling it.

Perhaps you've got Joergs mystery google link scrambler :)

Ah, you are reading via google groups!

--

John Devereux

Hey, be depressed if you enjoy it. I'd be depressed if I were you.

That's all you know!

All I do is double-click on them in Agent and they open. You can also paste the links into your browser url window.

Can you open *any* pdf files from the web?

I was only about 14 or 15 years old when I did the scintillator and lidar stuff. That was fairly early in my experience with PMTs.

I also did some double-slit and no-slit optical interferance stuff, and a home-made Kerr cell, flashtube LIDAR, and alpha scintillation with PMT detectors. I got nitrobenzene all over me. Not long ago I read a Nero Wolfe mystery where somebody was murdered by spilling nitrobenzene on them. Between that and the HV, I'm lucky to still be here.

I had one PMT in a tube with a lens, amplified into headphones. It was cool to aim it around and listen to the light.

VR tubes are certainly selectable... just plug a VRxxx into a socket.

I recall running 931As at uniform voltage spacings, but I was just 15 at the time. They seemed to work fine.

John

Same here, using wget.

Looking at Bill's post:

"The requested URL /external_content/untrusted_dlcp/

was not found"

showing it's another Google-redirecting-URL fuckup.

If Bill copies and pastes the original URL, with http:// in front:

into his browser address bar, and hits go, it'll happen.

As regards Google, I'm with Joerg. It rocked ten years ago. Now it sucks.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

nd run

r-high

Once I got rid of the "/external_content/untrusted_dlcp/

en//" bit they worked fine for me too. I'd forgotten that I'd let Firefox up-date itself recently ...

I'm actually paying Forte for proper usenet access, but the google search engine is seductively helpful.

-- Bill Sloman, Nijmegen

w.inl.gov/technicalpublications/Documents/2808460.pdfwas not found"

It did.

I doubt if it is Google. It used to work, but Firefox just up-dated itself ...

-- Bill Sloman, Nijmegen

nd run

r-high

I can live with being depressed about your intellectual failings. I'd be more depressed if they were mine.

That's what I enede up doing, and it worked

Don't be silly. Clicking on a link from within Firefox always used to work, and mostly works even now, but I let Firefox up-grade itself to

7.01 a day or so ago, and something clearly got broken in the process.

Lucky you. I didn't get to play with them until I was a graduate student - I would have been all of 23 years old at the time.

The Brat is probably even luckier - nitrobenzene is a testicular toxin

Who knows what you might have achieved if you'd be able to play with PMT's at 5 or 6 years of age.

Selectable isn't adjustable. You typically adjust PMT gain over a range of about a thousand, which involves changing the PMT supply voltage by a factor of about 2.4 . Cambridge Instruments scanning electron microscopes came with an automatic gain control circuit to save the user from the endless fiddling that would otherwise have been necessary. The regular version didn't work well when you were looking at individual electrons.

-- Bill Sloman, Nijmegen

run

super-high

That surely ain't my fault.

I was into chemistry then. I cut over to electronics when I was 9.

John

/external_content/untrusted_dlcp/

not found"

Right-click on the link. Copy Link Location. Paste into the Firefox URL field. Hit enter or use the go to arrow.

If it doesn't work, curse me.

//

Obviously not. Why do you need to bother to tell us that?

e

Both my parents had bachelors degrees in chemistry - it took me longer to get around to electronics (and I was pretty good at chemistry, which made it a more effective distraction).

-- Bill Sloman, Nijmegen

On a sunny day (Wed, 12 Oct 2011 12:44:03 -0700) it happened John Larkin wrote in :

One thing we tried in the old black and white TV studio, was to take the PMT out of the film scanner, and point it to some nearby monitor (no lens needed). Since all monitors, including the film scanner, were externally synchronised and in sync, on the film scanner monitor you would see the image of the screen you pointed at. So the thing you pointed at worked as 'flying spot'. Of course the image was smeared, as the persistence of normal TV tubes is rather long. You can, or rather you could in the old CRT days, do the same thing by picking up BW TV transmissions through a window.. free viewing :-) There was a paper some years ago discussed in sci.crypt where they used a PMT to monitor a modem carrier light from some distance aways, and used it for eavesdropping. Seems that modem LED flashes with the data. PMTs make all sort of fun things possible.

On a sunny day (Wed, 12 Oct 2011 09:18:49 -0700) it happened John Larkin wrote in :

You are fortunate to have been to such places I guess. Thats is Japanese right? Once a Japanese company was trying to buy some of us, but after doing some research I found that working there was more like the chain-gang. So I declined, best choice ever.

Anyways, I am still experiencing a bit high power consumption with my inductor solution, and I will study the pdf your referred to a bit more to see if I can also test a voltage multiplier configuration. It occurred to me that with such a low voltage for each stage, the capacitors can be really small. So I want to test how much power such a configuration eats. With small caps and SMD diodes like I have it could perhaps be done within 10 cm. Will likely be in the weekend... Also the prospect of using a pure sinewave to drive it, and the resulting lower RFI, and the absence of magnetic problems could be a plus.

[...]

I'm using Firefox and had no trouble with the links.

PEBKAC?