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

[JonW]

Nice one, Ken.  You should do a few pages on using LT Spice, as you seem to have an excellent understanding of it. 

[Fanie]

quote author=ken_k link=msg=20691 date=1749001345
https://www.youtube.com/watch?v=Ud6WCusQdm4

That is a phosphor source, similar to the phosphor they put on watches. Radiation is very low and is shielded off by just about everything except the light you can see, and probably why you cannot measure the radiation in the video.  I have a phosphor source and I've had it for more than 20 years, still glowing 24/7.  It probably went past it's half-life a few times already.
The radio active light source used in WW2 actually made light like a lamp, not just a glow-in-the-dark. If you use something like this around your house you'd have permanent light for many years. The glow sticks you get off late is a chemical reaction and works only for a few hours.

Off topic, but you may find this video humorous
https://www.youtube.com/watch?v=fgqFbs7My9c
 Radio Lifeboat Aka Sea Rescue (1958)
I like how three guys helps the girl out of the inflatable.  If it was a guy he would have to get up by himself

[John Drew]

Reminds me of the time way back in the late 1950s while studying physics at Uni we were using a Geiger Counter to examine material so I checked my watch out of curiosity.
The count was frantic. My practical supervisor said I should get some of the material removed which I did. The markings became less bright but still OK.
I believe that years ago they used radium and ZnS to make things glow but I have no proof mine was radium and I didn't grow an extra ear so maybe it wasn't:-)

John

[ken_k]

Nice one, Ken.  You should do a few pages on using LT Spice, as you seem to have an excellent understanding of it. 

I do find spice essential for almost all my work. I have produced a few simulations for you to try.
Install LTspice.
Make a directory somewhere and place the enclosed files in it.
Remove the .text.
Run the analog display 6BIT.asc and give it a try.
No special library's will be needed.

John I'm glad you didn't grow an extra ear, I have a small lump developing. A radio ham friend of mine found he had radioactive dust in his shack from the dials on old vintage WW3 aircraft equipment. I was going to repair my dads old fob watch, the dial glass kept falling off, the phosphors no longer glowed. I hot glued the glass onto the watch and it is now one of my better radioactive sources.
analog display 6 BIT.asc.txtFor_LES.asc.txt 

[charliecoutas]

I work with a few ex British Telecom engineers at the museum. One gave an explanation that when British Telecom brought out the Trimphone (in the 1970's I think), there was a limit on the number of phones that could be packed into one carton. The reason was concern about the radioactive numbers on the dials.

But I have discovered that ex BT engineers didn't need any extra radiation to become funny chaps (in the nicest possible way).

Charlie

[RGV250]

old vintage WW3 aircraft equipment

Have I just woken up in a time warp

[top204]

This is an excellent thread, and very, very interesting, and fun to read.

I noticed that as well Bob, and was going to change it, but it was too good of a mistake to change. Sorry Ken. :-) If I did not go through my posts a few times after I have written them, virtually every other word would be incorrectly spelled, or totally wrong. LOL

The Neon I used was an older (1930s/1940s) large "bulb type" neon with a screw base, that once belonged to dad. A bit like a 15 watt bulb, but unfortunately, with my many moves in life, it got discarded along the way. :-(

I have looked at the geiger tubes on AliExpress, and once you get past the con-artists on there that advertise at £3.95, but when you actually get to it, it is more like £23.95, some are quite a good price (excluding taxes). The eastern european geiger tubes are now stupid prices on ebay, and crazy postage costs, so they are a no. no for me. I rarely go on ebay now, because it is so full of greed, and prices are stupid on there now. It was once a lovely site, with good prices for "old" stuff that people no longer needed and wanted to get rid of.

I'll see if I can get a chinese geiger tube and run some tests as well. Many thanks for the kick-start of the idea Ken.

The ready made units that measure radiation are good, but the joy is in the designing and making, and a geiger counter is not a geiger counter without the clicks and a round analogue meter. :-) Maybe, I'll see if I can use an image of an analoque meter on the round graphic LCDs, and create the needle image with trigonometry, or even multiple images of a real needle moving. It will need to be on a dsPIC33 device, because the background image will need to be refreshed everytime the needle moves, which will be too slow for an 8-bit device to do at a resolution of 240x240 with an SPI interface.

A bit like I did here: An Analogue Meter Emulator with a CG9A01 TFT, but with a more realistic look to it.

The Photo PIN diode method was a couple of project ideas in the Elektor magazine about 20 years ago, and apparently, they work quite well with some radioactive particles, and the new semiconductor radiaton detectors work on a similar principle to them.

Best regards
Les

[ken_k]

the joy is in the designing and making, and a geiger counter is not a geiger counter without the clicks and a round analogue meter. :-) Maybe, I'll see if I can use an image of an analoque meter on the round graphic LCDs, and create the needle image with trigonometry, or even multiple images of a real needle moving. It will need to be on a dsPIC33 device, because the background image will need to be refreshed every time the needle moves, which will be too slow for an 8-bit device to do at a resolution of 240x240 with an SPI interface.

Sounds like an excellent idea. If using a micro one can log data and provide all sorts of data on other selectable screens. It would be easy to display radiation in the unit of your choice and to have an easy calibration screen for different Geiger Muller Tubes. I believe there are phone aps the device could connect too, maybe using Bluetooth. If you wanted to go all out you could include other sensor types, maybe an ion chamber for high level radiation.

https://www.flukebiomedical.com/products/radiation-survey-meters/451b-ion-chamber-survey-meter-beta-slide

https://maurycyz.com/projects/ion_chamber/

BTW a transistor darlington would drift too much with temperature.

Who is to say WW1 was not 100000 years ago!

This is a picture of a Geiger Counter with a tube from Russia, I do not like the look, easy to calibrate at the boot up screen, it has a good click. I have one with only a large moving coil meter it looks a lot better. The vintage look is a good use for my old PCB CNC mill when used for engraving. Re the engraving, I engraved, spray painted, and then used a spirit based black felt tip pen to fill in the text, very easy and quick.
Your idea of a "fake" vintage meter is excellent.

BTW I just had a thought, you could use a rotary switch and chicken-head knob to select all the other screens. You might even be able to sell some as movie props.

[Wimax]

Some months ago I designed and tested a Geiger counter with a LCD display. It's based on the Soviet SBM-20 tube, the counter is controlled by a dsPIC33FJ and device sends also serial data to the PC, it works fine, I just have to find the time to put it in a enclosure.
To test it without hurting myself I used the old Auer camping net, a little bit of Thorium in life is good !

[ken_k]

Some months ago I designed and tested a Geiger counter with a LCD display. It's based on the Soviet SBM-20 tube, the counter is controlled by a dsPIC33FJ

Well done. The SBM-20 is quite a good GM tube, not so cheap any more. I have some dsPIC33FJ's about, a good choice. My older devices were too hard on batteries, the CMOS version is good as far as battery life is concerned. What is the current consumption of your Geiger Counter?

I've had a Chinese J321 GM tube running for a couple weeks now, it is readily available.
specs
The J321 Geiger-Müller
technical parameter
Diameter: Φ 10±0.5 mm
Total length: 86 ± 2 mm
Initial voltage: < 350V
Recommended working voltage: 380V
Minimum terrace length: 80V
Maximum socket slope: 10%/80V
Working voltage limit: 600V
Maximum background count rate: 25 times/minute
Lifespan: > 1 × 109 pulses

I need to test the tube in the dark, under bright light, and UV light to see if it affect's the reading.

I purchased the J321 I'm running from AliExpress from the MOMO HOT SALE store for $16.46 AUD on the 4th of May this year. I wanted to try out a Chinese tube. I will leave it running 24/7.



The 3 to 5pF across the 10 meg is not required more C loading the tube is normally bad for tube life.

[trastikata]

Some months ago I designed and tested a Geiger counter with a LCD display. It's based on the Soviet SBM-20 tube, the counter is controlled by a dsPIC33FJ and device sends also serial data to the PC, it works fine, I just have to find the time to put it in a enclosure.

I did practically the same last year, however I have a collection of rocks and some are quite emitting - so it was easy to test it. The purpose was to measure and log natural background and some rocks while hiking so I placed a GPS to log the time, date and position.

Tip: If you place a voltage divider at the high voltage generator with 1 GOhm resistor and cheap pico-amp amplifier, you can set the Geiger tube voltage, monitor it without loading the generator and keep the high voltage constant. Here's one rock ...