Sorry no PIC here.

[ken_k]

Hi all.
Please let me know if my non PIC post don't belong here. As a retired person all sorts of thing seem to amuse me.
Here is a link to my latest project. It is another geiger counter that will be assembled into a 1950's looking enclosure.
It could easily be fitted with an external PIC pcb to display and log data. Notice I said a PIC pcb and not an arduino or ESP32 :-)

The main advantage of this design is the low current consumption.

Regarding the use of 4000 series CMOS they handle radiation very well, look it up.

https://sites.google.com/view/kensanaloggeigercounter/home

[charliecoutas]

No problem whatsoever here Ken. It looks like a well thought out piece of kit, I'm sure Les will approve.

But my worry is this: why do you need a Geiger counter, particularly as the world is becoming a rather dangerous place? In any case, I'll order a board from you just in case. Where do you get the tubes?

Best
Charlie

Is Ken Kranz your Australian stage-name?

[ken_k]

Where do you get the tubes?

Ebay or AliExpress
Russian Geiger Muller tubes from the USSR were once cheap, not so any more.
This may help you evaluate some tubes.
https://sites.google.com/site/diygeigercounter/technical/gm-tubes-supported
The device on test is a J321 a Chinese type.
I have some SI-180 and a SBM 20 Russian tubes.
Some geiger counter designs are brutal on tube life, do not connect too much capacitance across the tube as when the gas ionizes it has to discharge the extra capacitance. Many designs take the output from the outer negative electrode often a brass tube these can be prone to RFI. My designs always ground the neg electrode.
Geiger counters are simple and fun to play with. The physical size of a detector is also important. Think drops of rain on a square meter or a square centimeter in a light rain.

There are better ways to measure radiation these days.
https://www.youtube.com/watch?v=xR2fTqY2sTU

Ken Kranz is my actual name.

[top204]

That is a wonderful circuit Ken, but would be better with a few valves, however, CMOS 40 series devices are also excellent, and bring back some good memories. :-) Your circuit actually operates as a geiger counter and a dosimeter, with the count on an analogue meter? Very nice!

On a side note... I did not realise that the word "analogue" is spelled the American way in Australia as well. i.e. "analog". You do call "aluminium", "aluminium" though don't you, and not miss out an "i"? LOL

I have some photo PIN diodes knocking around somewhere, that I bought about 20 years ago, to try them as radiation detectors, but never got around to it, and there are now dedicated semiconductor radiation detectors. But that takes the fun out of applying a high voltage to a geiger-muller tube. Apparently, some of the eastern european tubes from the cold war available online are very insensitive, and only detect certain particles. But only a few particles and hearing the tick is enough for the joy of building and using it. :-) I'll have to get myself a geiger tube and see if they are OK, so your tests and findings would be very useful.

Many years ago, I tried a neon tube as a radiation detector and it worked well, but the biasing of it was problematic, as it has to be constantly adjusted to just before the neon ignites. I even bought a block of uranium ore about 20 years ago, for a couple of quid, that looks like granite, which is what it is, from the south west of England. It is kept in a sealed metal tin, and in the loft, until I get back into radiation detecting, as it has always fascinated me. I even have a small metal unit that has the radiation material from a smoke detector. Americium I think they call it.

Did you know that quite a lot of the lead on this planet is decayed uranium, but not all of the lead?

[charliecoutas]

Ken, I'm sorry to have confused you with somebody else. Thanks for the feedback and info on tube suppliers. When I get some time I might have a go at your circuit. What you say about the physical size of the tube makes a lot of sense.

Best
Charlie

[Fanie]

We sure have encountered amazing things in our lifetime.  A few hundred years ago and before pics I made a coke detector for coke ovens (coke is used in furnaces) using a Geiger counter.  It would show the operator if the oven was loaded or empty and was mostly unaffected by heat, dust and smoke over some 10m ? with a radio active source on the other side of the ovens.
There was also a tower which hosted some weighing equipment.  If a blockage occurred you had to climb up in the vast darkness to reach the equipment.  You go in white but if you get out you are black, even your teeth.  Just the eyes have some white left.  You had to bath twice because the fine coke dust was that sticky and your hair feels like grass.

They used radio active sources to detect cracks in the steel usually railway tracks, the source is run alongside the one side with a geiger on the other, a crack would then output a spike.  So one day the shift changes and one guy notices a funny shaped object on his way home and put it in his pocket to look at it later.  Turns out the source was lost and by the time it was discovered the source was not in it's castle (big lead housing) and the guy was found, most of his ribs had disappeared.  He didn't live long after either if I remember right.  Terrible technology if it goes wrong.

One of the workshop managers had a WW2 emergency source that would emit light, used for evacuating ships in emergency crafts.  It was apparently illegal to have, but we used it to test our geigers and the emission was not dangerous.
I wanted to use a source to boil water into steam for cheap power generation, but the old Afrikaner Sick Africa would not have it.

[ken_k]

Many years ago, I tried a neon tube as a radiation detector

Unfortunately the strike voltage is affected by ambient light to some extent. Some small neon lamps have a radioactive substance in them to aid striking.

Quote from Wikipedia:

The lamp glow discharge lights at its striking voltage.The striking voltage is reduced by ambient light or radioactivity. To reduce the "dark effect", some lamps were made with a small amount of radioactive material, typically Krypton-85, added to the envelope to provide ionization in darkness.

Maybe a radioactive substance in a device designed to detect radiation may be detrimental.

I have a lot of NE2 neons and about 50 smaller cheap Chinese ones, I might test to see if they are slightly radioactive.

Re the spelling of analogue. Analogue is correct for Australia, analog is lazy Ken's way to save a couple letters.

BTW thoriated tungsten electrodes used in TIG welding are useful as a radiation test source.

[ken_k]

One of the workshop managers had a WW2 emergency source that would emit light, used for evacuating ships in emergency crafts.

https://www.youtube.com/watch?v=Ud6WCusQdm4

I like this post in the comments.
I carried one on my keychain for 5 years with no ill effect,,  as a matter of fact my hearing has actually improved with that new ear growing in back of my head.

https://wolph.com.au/products/tritium-gas-lamp-with-25-year-light-span-for-outdoor-camping?variant=40259136782525&utm_source=google&utm_medium=cpc&utm_campaign=google%2Bshopping&srsltid=AfmBOorRBh1vzMt9LGGZ3O4hCTExUutQJrrY7RcQAHV_ush4x-VX2W8eDPg&shpxid=1443c307-3c8c-45ab-8763-fc6fd08fa56d

[ken_k]

I wanted to use a source to boil water into steam for cheap power generation,

A pellet of Plutonium-238 oxide will heat your water for a lifetime.
https://en.wikipedia.org/wiki/Plutonium-238