Prepping 101: DIY Radiation Geiger Kit V2

This VII device has the same basic layout and features as the VI. The bottom right is the accumulated dose, and it gives you a graph as well.

This VII device has the same basic layout and features as the VI. The bottom right is the accumulated dose, and it gives you a graph as well.

With the Russian/Ukraine conflict now going hot, we really need to return to the topic of radiation, since both of these are nuclear armed countries, with nukes pointed at us. In part one of this article we covered the basics of inexpensive Geiger counters and the basic need to have one. Radiation is silent. Without a way to measure it where you reside, you will never know if you are being bombarded by a nuclear event, or whether that mushroom cloud you saw in the distance was just a conventional explosion. Dirty bombs, nuclear reactor accidents, suitcase nukes and of course ICBMs are scary things, but with your own Geiger counter you will instantly know if you are in danger or if, for now, you are not in danger. In this article we will use the $80 Version II MyGeiger kit that I ordered pre-soldered ($12), and the $20 SBM-20 Geiger tube. We will take a look at the actual numbers when it comes to radiation, as well as the free logging software. And most importantly, we will discuss the only preventative measure that you an take to protect you from radiation poisoning. It worked on nearly 100% of those treated after Chernobyl. If a nuclear event is coming, those without this key inexpensive ingredient on hand will not be happy campers.

Radiation as it effects humans is measured in “sieverts.” One (1) sievert is thought by researchers to carry an additional 5.5% chance of developing cancer. Most of the US has a baseline radiation level of .1 μSv per hour. The μSv stands for micro-sieverts, or millionths of one sievert, three decimal places to the left of milli-sieverts, or msv. This data from the Wikipedia page will give you an idea of what normal life will subject you to:

The various levels of radiatiion are available on the Wikipedia page for sieverts. You would be surprised how many things we do expose us to higher levels of radiation.

The various levels of radiation are available on the Wikipedia page for sieverts. You would be surprised how many things we do expose us to higher levels of radiation.



0.098 µSv: banana equivalent dose, a whimsical unit of radiation dose representing the measure of radiation from a typical banana
0.25 µSv: U.S. limit on effective dose from a single airport security screening
5 to 10 µSv: one set of dental radiographs
80 µSv: average dose to people living within 16 km of Three Mile Island accident
0.4 to 0.6 mSv: two-view mammogram, using weighting factors updated in 2007
1 mSv: The U.S. 10 CFR § 20.1301(a)(1) dose limit for individual members of the public, total effective dose equivalent, per annum
1.5 to 1.7 mSv: annual dose for flight attendants
2 to 7 mSv: barium fluoroscopy, e.g. Barium meal, up to 2 minutes, 4–24 spot images
10 to 30 mSv: single full-body CT scan
50 mSv: The U.S. 10 C.F.R. § 20.1201(a)(1)(i) occupational dose limit, total effective dose equivalent, per annum
68 mSv: estimated maximum dose to evacuees who lived closest to the Fukushima I nuclear accidents
80 mSv: 6 months stay on the International Space Station
250 mSv: 6 month trip to Mars – radiation due to cosmic rays, which are very difficult to shield against
500 mSv: The U.S. 10 C.F.R. § 20.1201(a)(2)(ii) occupational dose limit, shallow-dose equivalent to skin, per annum
670 mSv: highest dose received by a worker responding to the Fukushima emergency
1 Sv: Maximum allowed radiation exposure for NASA astronauts over their career
4.5 to 6 Sv: fatal acute doses during Goiânia accident
5.1 Sv: fatal acute dose to Harry Daghlian in 1945 criticality accident
21 Sv: fatal acute dose to Louis Slotin in 1946 criticality accident
64 Sv: nonfatal dose to Albert Stevens spread over ~21 years, due to a 1945 plutonium injection experiment by doctors working on the secret Manhattan Project.

Different tubes will give slightly different results because they run as slightly different voltages. We bought two devices and tested ten tubes. They were all pretty close.

Different tubes will give slightly different results because they run as slightly different voltages. We bought two devices and tested ten tubes. They were all pretty close.


The sievert is preferred over other measures of radiation because it is calculated as an effect on human tissue, and different types of radiation have slightly different conversion factors, with Alpha radiation rating extremely high. This is not an exact science. Different types of body tissue absorb radiation differently, so at no time should you think it is ok to go out into a radiation saturated environment thinking that you are measuring risk with your Geiger counter. Human cells can repair themselves to some degree, but once you are exposed to radiation there will always be a risk of early death. People died of Thyroid cancer decades after the bombs landed on Hiroshima and Nagasaki.

No matter what type of Geiger counter you buy, as long as you are getting a background radiation measurement it should be easy to rely upon the unit to notify you of a local nuclear event. The old yellow CDV meters measure in Roetengens, which are more of a pure measure of radiation, but once you have that baseline on your meter, you’ll be able to tell if the rate has risen. Note that these are low level meters though, which means that they may blank out at high levels of radiation, as I explain in a subsequent article on CDV meters.

The VII MyGeiger kit is the cheapest device I have seen consistently available at this price. The tubes are also very available, and as low as $15 with free shipping from Russia right now on Ebay. In the first article we focused on the VI kit, because I hadn’t been able to get the VII, but if you don’t already have one, I would buy the VII kit. You don’t need an extra interface to use it with the free Radiation Logger software, and it uses a regular USB instead of a printer cable to connect. The circuit has also been modified to handle a higher level of radiation, and the overall assembled board is cleaner and less subject to getting bumped. You can and should make an enclosure for the kit, but beware that the battery sold by the Radio Hobby Store, or at least the one that came with my kit, didn’t have the right connector. It can be powered via the USB as well.

If you think about the the term Geiger counter, you can understand what one does. The tube is called a Geiger-Mueller tube. When charged with 400 volts or so, the GM tube registers an electrical charge when it detects any radiation. The circuit and display count these pulses, and converts them to a dose measurement. This particular tube is capable of sensing Alpha, Beta and Gamma radiation, but if you are indoors when an event occurs you really only have to worry about the Gamma, though some Beta exposure may be possible. Alpha particles are very heavy and fall to earth quickly. They also have half lives of only a day or two for the most part. Beta also has a short half life, but they can remain airborne much longer.

The Radiation Logger software that comes free with these devices will show a slightly different dose per hour because the algorithm is slightly different than the one in the chip of the device.  This can be adjusted with a setting in the software. The counts per minute will be the same.

The Radiation Logger software that comes free with these devices will show a slightly different dose per hour because the algorithm is slightly different than the one in the chip of the device. This can be adjusted with a setting in the software. The counts per minute will be the same.


The Radiation Logger software will track and log radiation for a long time and graph it for you. These are somewhat scientific features as opposed to survival features, but the software does allow you to adjust your conversion algorithm depending on how your tube performs. On Windows 8 I was able to just install the software, plug in the USB and it worked as promised. Stick to the 1.4 version if you want the software to accumulate the radiation for you. The display on the Geiger counter will do this as well, but it resets when you restart the device.

In the Event of an Event

The only known protection against radiation poisoning is Potassium Iodide. This is a fairly plentiful substance that is used in photographic developing and to treat thyroid illness. In all of my research that I have done for this prepping column, the scariest thing I have encountered is that buying potassium iodide in bulk is tracked by the government. To buy it directly from the biggest photographer’s supply, it costs $69.99 per pound. But hold your horses. In order them to to sell it to you, you are required to fill out a DEA form and submit the photography recipe that you intend to use it for. Apparently, potassium iodide can be used to create crystal methamphetamine. Therefore it is regulated. I have not found what the penalty would be for making up a recipe, but not actually using the potassium iodide to make meth. There are plenty of valid recipes easily Google’able. There is a huge advantage to having a bulk supply of potassium iodide on hand, if you are willing to jump through the DEA hoops to get it. If you read the Wikipedia page, it has the unique property that if you dissolve it in water the dosing is exactly what you need. Cost wise, it isn’t even close. The pills are 130 milligram doses, and one pound equals 453,592 milligrams. In a nuclear event, that will treat a whole lot of people, and having it immediately on hand is absolutely imperative.

Most of us are not going to fill out a fake recipe to buy KI in bulk from photography supply, so we have to buy IOSAT or other pills at a premium.

Most of us are not going to fill out a fake recipe to buy KI in bulk from photography supply, so we have to buy IOSAT or other pills at a premium.


Those of us who don’t wish to deal with the DEA helicopters in the front yard have to buy potassium iodide pills, the most common of which is the IOSAT brand, $6.99 per person on Amazon. This gives you a 14 day supply of KI (the elemental name for potassium iodide), 130mg per day. You can find better deals on Ebay and Amazon, but the pills may have a much shorter shelf life because they are not sealed in foil. Who knows. KI is a salt, so maybe it never breaks down.

How important is KI? In the wake of Chernobyl, the Polish government provided KI to 30 million people, just in case. Tens of thousands of Ukrainians who hadn’t supplied themselves with KI developed thyroid cancer in the following years. Those around the disaster who had KI on hand and took it showed no thyroid cancer at all. Thyroid cancer was the only measurable cause of deaths after Chernobyl. Read the Wikipedia page if you have any doubt. it is very clear that KI will protect you from the primary harm of radiation exposure.

How does it work? I can only give you a superficial explanation. As explained, thyroid cancer is the primary cause of illness and death after radiation exposure. The thyroid gland is a sponge for any iodine that you ingest, until it is saturated, then it absorbs no more. Both a nuclear reactor meltdown and a nuclear bomb explosion produce the radioactive isotope iodine 131. If you take KI before or just after a nuclear event occurs, it will saturate your thyroid with iodine for a day. So why does the IOSAT give you 14 days? Because iodine 131 has an 8 day half life, so after 8 days it begins to decay, and by 14 days it is pretty much done (this was a corrected brain fart thanks to the comments below).

I have read that all postal employees are given a supply of KI, though I haven’t been able to confirm this. In January of this year, the Department of Health and Human Services bought 700,000 20 pill packages. Potassium iodide is perhaps the biggest survival non-secret that few people seem to know about of all time. If you don’t have KI on hand, you are not prepared to survive a nuclear disaster, or war, and a whole lot of other people are. Just do it.

Discovering a radiation event, being able to measure it, and being able to act on that knowledge are not terribly expensive things. You don’t have to pay $500 for a Geiger counter now, or $5,000 after an event happens. The pre-soldered VII kit is an extremely advanced tool that has been hardened in VII for extreme radiation exposure, and that comes out of the box ready to go. You can buy KI on Amazon and Ebay even cheaper per person than the IOSAT brand pills. There is no mystery to radiation, and empowering yourself to survive just isn’t that hard. As I have said throughout this series, ten years early is better than one day late.

{ 13 comments… add one }
  • Karl Vanhooten September 17, 2014, 6:22 pm

    You prepper guys are full of crap. Even if you and your family survive a blast and the resultant nuclear winter, and the Zombie apocalypse, you are going to die eventually. What’s the point? Nine more months of life with increasing radiation sickness and watching your family die in front of you? Oh, give me a home where the buffalo roam and 5,000 rounds of rifle ammo. Then what? Get real!

    • Administrator September 17, 2014, 6:32 pm

      We are just trying to buy a little extra time to see if we can see if we can get into hell.

    • Michael Crouch September 22, 2014, 5:15 am

      You non-prepper pukes make me sick, if you hate the idea of self-reliance, then why are you here? Go read the latest crap on the kardashians or whatever pop-culture garbage the leftists are currently loving.

  • John Lopopolo September 8, 2014, 5:27 pm

    Radioactive fallout is particulate. Wash anything exposed outside and you will wash it off. Rinse any food items. If you have water pressure available wash the outside and roof of your house/ shelter. Be careful to dispose of sediment, the sediment can be concentrated material (sediment traps in plumbing, rain gutters ect.) This info used to be taught in school and in the military. Your Geiger counter will only show up ionizing beta radiation, it will not show alpha or neutron radiation.

    • Tararam Pararam September 9, 2014, 5:31 am

      All four types of radiation you mentioned – alpha, beta, gamma and neutron – are ionizing. The biggst problem of the fallout is not the dust on you or your belongings, it is dust everywhere that creates a field up to 5,000 R/h (initially). That kills.

  • Russ September 8, 2014, 12:44 pm

    Ya, radiation saturation is where I give up folks.
    Unless for some reason I’m near or can get to a huge cave system.
    Put me on a space station, so I can look down and cry.
    I don’t know how much I would enjoy the new mutated world, or even try to pull it off.

  • alex gregis September 8, 2014, 7:23 am

    you have to be kidding me!!!!

  • Tararam Pararam September 8, 2014, 5:27 am

    Thank you for the article. Couple of comments:

    “… since both of these are nuclear armed countries, with nukes pointed at us” – Ukraine is not a nuclear armed country, however it had the 3rd largest stockpile of nuclear weapons in the world at some point. In 1994 they gave all their nukes to Russia in a deal between Ukraine, Russia, United Kingdom and the US, in exchange for guarantees of sovereignty and territorial integrity of the Ukraine. Ironically, that is Russia, one of the guarantors, who is now invading the Ukraine. At no point the Ukrainian nukes were pointed at US.

    “The old yellow CDV meters measure in Roetengens, which are more of a pure measure of radiation, but once you have that baseline on your meter, you’ll be able to tell if the rate has risen. ” – the old CDV meters, CDV 710, 715, 717 etc. – except for CDV-700 – are ion chamber meters designed to work in very high radiation fields. They all read 0 in normal situation – as they should – and there is no way to check whether they are in a working condition nor establish “baseline” for those, unless you calibrate them in a lab.

    “The only known protection against radiation poisoning is Potassium Iodide. ” – that’s not true, there are different radioprotectants exist (like this one – http://en.wikipedia.org/wiki/Ex-Rad) however general public is not aware of them. KI should be used ONLY shortly before (or immediately after) exposure to I-131, it will not help in any other case and may cause more harm than cure if taken improperly.

    “So why does the IOSAT give you 14 days? Because iodine 131 has a 16 day half life. After that it begins to decay, and is no longer a threat. ” – I-131 has a half life of 8 days. Also, it does not “begin to decay” after that, it decays all the time, that’s the nature of radiation. In 16 days the amount of I-131 just drops down to 1/4 of initial amount.

    “You don’t have to pay $500 for a Geiger counter now, or $5,000 after an event happens. The pre-soldered VII kit is an extremely advanced tool that has been hardened in VII for extreme radiation exposure” – well, there is a reason why some instrument cost $500 now. The Russian SBM-20 tube you used has a dead time of ~190 usec that translates roughly to 150 mR/h (1.5 mSv/h) max dose rate measurement capacity. If you would encounter a nuclear event with a radiation field (dose rate) say, 0.5 R/h, your meter will just show 0. That’s even with compensation for the dead time; if the electronic uses “time-to-count” technique the upper limit will be more, say 1.5 R/h but that’s it. You should be aware of your device limitations. Canberra UtraRadiac’s upper limit is 200 R/h but costs way more than a simple kit from eBay. I am not even discussing the effect of EMP on electronics – if you plan to measure the fallout radiation with the meter like yours, not EMP hardened, you may be (un)pleasantly surprised with the results.

    But in general, I agree with you – it is better to be prepared than not. Just know your equipment and subject well.

    • xshooter September 8, 2014, 9:15 am

      I-131 half life is 8 days not 16.5 days.

      • Tararam Pararam September 9, 2014, 5:32 am

        Yes, that’s what I said.

    • Administrator September 8, 2014, 10:08 am

      Proximity to a gamma radiation source should follow the inverse square rule. If you are indoors alpha and beta are not as much of a concern. We have tested the SBM-20 meters with thorium treated mantels that register in the 300 usv an hour and they both work fine. The new circuit, if you read the docs, is built to withstand very high levels of radiation. Considering that if you are in the blast zone, you are dead anyway, following the inverse square rule, after an event, these meters will more than suffice to tell you that an event occurred and if you are in a zone from which you should try to leave. The SBM-20 actually can detect beta radiation as well, so it is safe to put the meter outdoors to see if there is fallout in addition to a gamma source. Your comments are misleading, and most likely meant to try to sell radiation meters that are overkill for a anyone on a budget. And EMP hardened lol? What exactly is the antenna source on the little meter? The important thing when you know just enough to be dangerous is knowing that you know just enough to be dangerous.

      • Tararam Pararam September 9, 2014, 5:28 am

        1. The inverse square rule applicable only if you deal with point radiation sources. If you are in the radiation field (i.e. radiation is everywhere) – that’s typical situation post-fallout or post-Chernobyl – the inverse square rule is irrelevant.
        2. Some radiological/nuclear events will create a radiation fields way more stronger that SBM-20 based meter can handle (as I already mentioned, it is a limitation of GM tube, no matter what amount of radiation the circuit can handle)
        3. You do not need to be in the blast zone to experience a very strong radiation field. Imagine being inside the shelter after the fallout (so you are not killed by the blast that happened 100 miles away). Inside the dose rate is 5 mSv/h, your counter shows 0 – no matter if you measure inside or put it outside. Not good.
        4. My comments are not misleading, your readers deserve to know that there are different types of events and many of them your kit counter will not handle.
        5. Lol or not lol but the EMP is a valid threat – see here – http://www.empcommission.org/docs/A2473-EMP_Commission-7MB.pdf As for the antenna – the GM tube will harvest more than enough energy to dmage the circuit. Small electronics (IC based) is very likely be damaged in fields above 20 Kv/m, not even mentioning the modern, HEMP-optimized warhead detonation.

Leave a Comment

Send this to a friend