Geiger Muller Tubes
20th Century Electronics B6H |
CV2247 |
CV2287 |
Dextray 3G8B |
DOB-50 |
DOB-80 |
EON Type 6993 |
FHZ66 |
HH614 |
J305 |
J306 |
J307 |
J308 |
J315 |
LND 712 |
M4011 |
Mullard MX123 |
Mullard MX124 |
Mullard ZP1210 |
Philips 18503 |
Philips 18504 |
Philips ZP1300 |
RD003 |
Robotron 70 013 |
SBM-10 |
SBM-20 |
SBT-10A |
SI3BG |
SI-8B |
SI-19BG |
SI-21G |
SI-22G |
STS-5 |
Victoreen 6107 |
ZP1302
Use the navigation above to go directly to a specific tube, and click on an image in the mini gallery by each tube to view the image full screen. To view the full max resolution, right click and open in a new tab. Fully updated as of 27/09/2026.
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Tubular thin-walled glass β Geiger–Müller tube. This tube was made by 20th Century Electronics that later became Centronic. This tube is application designed for dipping in liquids or gas sampling. This tube has a typed sticker on the base stating to operate at 400V, yet the specification states a working voltage of 370V. Specs:
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Halogen quenched Gamma radiation detector with neoprene sheath for portable use. The CV2247 Geiger–Müller tube was used in the 'British Contamination Meter No. 1'. The construction is a glass tube with a thick neoprene rubber protection boot over the tube. The connector is proprietary to the British Contamination Meter No. 1. This tube came with a complete Contamination Meter No. 1. Specs:
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Halogen quenched Gamma radiation detector. Was used by the military and/or government This particular CV2287 Geiger–Müller tube resides in a 'British Meter Dose-Rate Portable Trainer No.1'. The construction is a glass tube with a thick neoprene rubber protection boot at the base of the tube. The connections are simple solder tabs, both of which are at the same end. Searching about I found some detail that the tube was manufactured by GEC, General Electric Co Ltd. and in the datasheet it states *Prototype:-* 20th Century Electronics. Specs:
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Geiger–Müller Counter Tube 3G88. Never issued French Army surplus, manufactured 1960s. This is a low sensitivity Geiger–Müller tube designed for use in high radiation detecting counters. Excerpt from 1964 technical journal showing some of the tube specs: Geiger–Müller Counter Tube 3G88 - Under license of the French Atomic Energy Agency, a wide-range counter operating in the Geiger–Müller region has been developed for use in military equipment. In a suitable circuit, it will respond to fields from 0.001 to 1000 roentgens per hour without saturation. It will operate on 1 stroke per second per milliroentgen per hour. The tube, shown in Figure 9, is operable from -40 to +70 degrees centigrade. The Geiger–Müller threshold is 445 volts and a flat operating range occurs over at least 100 volts. The minimum detectable gamma and beta energies are 50 and 2000 kiloelectron-volts, respectively. The tube is 46 millimetres ( 1.8 inches) long and 13 millimetres (0.5 inch) in diameter. Laboratoire Central de Telecommunications France Specs:
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The DOB-50 Geiger–Müller Tube was designed in East Germany during the Cold War period, around 1970, and was produced for use in the Polish military. This is a low sensitivity Geiger–Müller tube and this particular one was taken from a non-working Polish DP-66M Geiger counter. Specs:
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Like the DOB-50, the DOB-80 Geiger–Müller Tube was designed in East Germany during the Cold War period, around 1970, and was produced for use in the Polish military. This is a low sensitivity Geiger–Müller tube and this particular one was taken from a non-working Polish DP-66M Geiger counter. Specs:
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Metal walled, Halogen quenched high sensitivity Geiger–Müller tube. Used in Victoreen and Lionel CD V-700 Civil Defence Geiger counters during the Cold War period This particular tube is from a Victoreen CD V-700 6b that has been stripped down for refurbishment. Specs:
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Little is known about this tube at this time. This tube resides in a Frieseke & Hoepfner (F&H) FH 40 H vintage Geiger counter I own. Some text relating to a similar tube - FHZ76V: 'this counter tube is actually a Philipps / Valvo 18550, there is also Data sheets. The counter tube is also compatible with the following tubes: Centronics ZP1320, Mullard Mx164 and LND-713. According to the Data sheet of the ZP1320 the tube is "calmed" to 9cps / mR / h at Cs-137 (Cesium, 540cpm / mR / h)' Specs:
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Stainless Steel tube inside a glass envelope. A new tube to the market and was seen around 2022. These are commonly found in cheap Chinese Geiger counters. This particular tube is from cheap, Chinese, HFS-P3 pen type Geiger counter. Specs:
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Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube from Shenzhen Sunvision Electronics Tech LTD Pictured left - the left tube is a J305βγ from 2019. Sadly the marking have rubbed off when cleaning. The middle tube is a slightly wider, more recent J305βγ from 2023 and the tube on the right (missing it's end caps) was taken from a cheap FS2011 Geiger counter. This may be a counterfeit GM tube as it bears no markings and the construction differs slightly to the two with markings. The J305 Geiger–Müller tube has become almost synonymous with low-cost Chinese Geiger counters. Some J305 Geiger–Müller tubes are sensitive to light and can cause erroneous readings when subject to UV or sunlight. However, some are not. The tube pictured left is light sensitive, yet the tube in the middle is not. This tube seems to have changed specification over time, or there have been variations thereof. These tubes bear the markings J305, J305β or J305βγ and have been found to have differing size specifications. People have reported differing lengths of 90~92mm, ~105mm and ~110mm. Specs:
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Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube from Shenzhen Sunvision Electronics Tech LTD This J306βγ is from 2023. Sadly the markings have rubbed off when cleaning. This tube is very much like the J305 and other glass walled Geiger–Müller tubes from Shenzhen Sunvision. The J306βγ is light sensitive and Specs:
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Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube from Shenzhen Sunvision Electronics Tech LTD This J307βγ from Shenzhen Sunvision is pretty much identical to the construction of the J306 and J308 but with slightly differing specifications. Images detailing the construction of this tube can be seen from the pictures by the J306βγ above. This has the same opaque black heat shrink type sleeve over the glass tube as the J306 and J308. I assume this tube is light sensitive too. Specs:
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Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube from Shenzhen Sunvision Electronics Tech LTD This J308βγ from Shenzhen Sunvision is pretty much identical to the construction of the J306 and J307 but with slightly differing specifications. Images detailing the construction of this tube can be seen from the pictures by the J306βγ above. This has the same opaque black heat shrink type sleeve over the glass tube as the J306 and J307. I assume this tube is light sensitive too. Specs:
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Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube from ? This J315βγ Geiger–Müller tube lives in a Yaorea YRG-01 Geiger counter. The J315 designation seems somewhat ambiguous as it can't be found among the group of other J3## tubes. It is possible this may represent an OEM/customer specific designation. CAJOE appear to have a new version of their popular counter, this is the Assembled Geiger Counter-V1.2-SMT, details can be found here. The specification of the tube shown with the CAJOE counter is remarkably similar to the M4011 tube, and measuring this J315 shows it to have the same dimensions as the M4011. This tube is light sensitive and is covered with an opaque plastic film inside the Yaorea YRG-01 counter. Specs:
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Mica end window Alpha, Halogen quenched, Beta and Gamma Geiger–Müller tube from LND Inc. A very compact yet sensitive end window Alpha, Beta and Gamma detecting Geiger–Müller tube. This tube was taken from a Sparkfun Geiger counter board. An excellent tube for small, portable counters such as the Gamma Scout. Specs:
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Tin oxide cathode, coaxial cylindrical thin glass shell structure, Halogen quenched Geiger–Müller tube, quite similar to the J305. This tube came in a GQ Electronics GMC-320 Geiger counter. Specifications for this tube seem a little fuzzy, but I did find a sensitivity spec (10-15 CPM / µSv/h) here. Specs:
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Halogen quenched, end window, beta Geiger–Müller tube. Also known as the Mullard ZP1470 This tube lives in the probe of a Mini Instruments GM Meter type 5.10. They were commonly used in medical Geiger counters in hospitals. Specs:
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Halogen quenched, liquid sample Geiger–Müller tube. This is an interesting tube. I bought a pair of these complete with their original boxes on eBay a short while back. I got them for a good price if I remember correctly. These are not unsimilar to the 20th Century Electronics B6H tube that are designed to work with liquids, however these differ in the fact they can be used like a test tube. These are like a test tube with a tube in the middle so the liquid surrounds the Geiger–Müller tube whilst being held in the outer tube. These look like a piece of lab glassware more than a Geiger–Müller tube. I can just imagine one being held in a clamp on a stand with two croc-clip wires hanging from the terminals at the bottom. Specs:
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Halogen quenched, Gamma sensitive Geiger–Müller tube. Also known as the Mullard MX120 and Philips 18520 and is very similar to the Robotron 70 013. This tube lives in a beautiful Panax TM64 B. Whilst the datasheet is dated 1980, the counter in which it lives is from circa 1960. The tube pictured is next to a STS-5 GM tube.
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Gamma and Neutron radiation (with modification) sensitive Geiger–Müller tube with Neon, Argon and Halogen quenching agent. Also known as the Mullard/Centronic ZP1200/MX147. This tube is almost physically identical to the Philips 18504 but without the end window. This one came, and lives in a Philips PW 4012 Geiger counter. It seems the 18503 and 18504 tubes are interchangeable in the PW 4012 Geiger counter, however the counter would require recalibration for the specific tube used. You can see this tube pictured next to it's Alpha counterpart, the 18504. Specs:
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Alpha, Beta, Gamma and Neutron radiation (with modification) sensitive, end window, Geiger–Müller tube with Halogen quenching agent. Also known as the Mullard/Centronic ZP1400. This tube is almost identical to the LND 712, and can be used as a drop-in replacement. It is also much cheaper than the LND 712 on the used tube market, at the time of writing - 24/01/2026. Specs:
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The Philips ZP1300 appears to possibly be one of the smallest commercially available, conventional Geiger–Müller tubes ever manufactured. Don't quote me on that, but I cannot find another commercially available GM tube smaller than this. There have been prototypes and experiments using even smaller tubes, such as Curtiss'/NBS needle counter (tube), but to my knowledge there is nothing smaller you can just buy. Also known as the 18529 or MX163 (Centronics?/Mullard). this tube is very low sensitivity and background readings are similar to the SI3BG with 0~3 CPM. It is a halogen quenched γ and high energy β Geiger–Müller tube. You can see it pictured on top of a bottle cap, next to a Micro-SD card and also next to my other possibly the smallest end-window GM tube in the world, the SI-19BG (M) (SI19BGM/СИ19БГМ) Specs:
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Gamma and hard Beta sensitive, metal walled, Geiger–Müller tube from Russia. This data was kindly given to me from the GC10 user's page. This tube is similar to a SBM-20, but slightly more sensitive. This one lives in a NetIO GC10next Geiger counter from Japan. Specs:
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High sensitivity Gamma and X-Ray sensitive, Halogen quenched, Geiger–Müller tube by VacuTec in Germany.. This tube is very similar to a Mullard MX120, ZP1210 and Philips 18520. Specs:
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A miniature, Gamma and hard Beta sensitive, Halogen quenched Geiger–Müller tube. This tiny tube is about 7 times less sensitive than a SBM-20, and certainly smaller. In the pictures you can see it with a British Pound coin and also next to a SBM-20. Ideal for a pocket Geiger counter. Specs:
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The SBM-20 is the quintessential Soviet Geiger–Müller tube from the 1970s to the 1990s Pictured left is an older, original style SBM-20 tube from the 1970's. Center is a more modern version from around the 1990's. Right is the slightly shorter SBM-20U variant with only one end cap and the anode exposed. All three variants have the same effective sense area. I have over ten of these tubes. They have become my go-to GM tube when I want a counter I can depend on. They are fairly robust and in testing their sensitivity is very close from one to another. It's a tube I feel I can rely on. Specs:
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The SBT-10A is a large, multiple anode (10), Gamma, Beta and Alpha Geiger–Müller tube. Primarily used for surface contamination detecting and monitoring, such as humans passing from one room to another. They would have their hands, feet and other parts of the body checked for contamination using the SBT-10A tubes, and in many circumstances, multiples of this tube working together. I have two of these tubes, but sadly both got damaged. You can read about them here and here. As a result I am unable to offer any more pictures of a complete tube. The SBT-10A is a very sensitive tube. It has ten anode elements separated by a common anode. Each section has the cathode curling around the anode under the mica window. It is Gamma, Beta and Alpha sensitive, but reports state the Alpha sensitivity would differ from tube to tube. It's forte is detecting Beta. Regular background counts can be over 200 CPM and I remember I seemed to get around 220 CPM background at home. The construction resembles somewhat like ten SBM-20's, sliced in half and stuck together with a mica window over them all. I used AI to translate and re-draw the datasheet pages, which you can find below. You can also see in the pictures the 3D printed connector I made, and each anode having it's own anode resistor. I settled with 30 Mohm resistors that was suggested online. Anything less than 5 Mohm would cause avalanches. These tubes also seem to suffer with some kind of black crystalline deposits, or spots appearing inside the tube on the underside of the mica window, although this doesn't seem to affect peformance. Specs:
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A small, low sensitivity, Gamma and hard Beta Geiger–Müller tube. This tube is hardly sensitive due to the cathode size and is intended for use in high radiation environments. It shows next to no background counts. I bought five at the time as they were very cheap - around £4 each. Specs:
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A large, high sensitivity, end window pancake Geiger–Müller tube, sensitive to soft Beta. This is a thing of beauty, and a joy forever. Very sensitive to small sources. This tube is quite fragile due to it's thin Mica window. The glue fixing the tube to the Bakelite back failed, so this was an ideal opportunity to photagraph it's innards. Specs:
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A miniature, low sensitivity, mica end-window, Gamma and hard Beta Geiger–Müller tube. This tube is possibly the smallest Mica end-window Geiger–Müller tube in the world. It is not very sensitive due to it's size. The window is approximately 6mm diameter. This tube was shipped from Ukraine and came with a couple of bits of paper in Russian. In the pictures you can see the tube next to a CR2032 battery and also next to an Am-241 button. Specs:
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A large, high sensitivity, Gamma sensitive Geiger–Müller tube. This tube is highly sensitive due to it's size. It is probably the longest Geiger–Müller tube I have. The long length (260mm) gives it an effective length of around 210mm, and so it has a very large capture area. This tube is a nice example and in great condition. It came with the original box and datasheet (in Russian) with the matching serial number - 310. Specs:
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A large, high sensitivity, Gamma and hard Beta Geiger–Müller tube made for the Soviet Military. This tube is quite sensitive due to it's size. Ideal for use in monitoring equipment and dosimeters. I have three of these. They are destined for either a β+γ / γ coincidence detector, or a muon detector. I originally bought two, but dropped one and feels like the anode is off centre and vibrates a little, so I bought another. The slightly damaged one still works, but exhibits either slightly more or less counts than the other two so won't be used in any counter. Specs:
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Moderately sensitive. Detects Gamma and hard Beta. This tube is very similar to the SBM-20. Whilst the electrical specs are very similar to the SBM-20, it should be noted that the STS-5 tube is slightly longer than the SBM-20. It can serve as a drop-in replacement for the SBM-20, but it might not quite fit due to it's length. Specs:
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Among the more intriguing relics of early radiation detection technology are the Victoreen 6107 / BS-212 Geiger-Müller tubes, believed to have been manufactured circa 1943–1944 by the Victoreen Instrument Company of Cleveland, Ohio. These devices are marked with "USN-C88M" and "MADE IN USA | 6107 / BS-212", clearly identifying them as products of a U.S. Navy contract during the Second World War. (AI generated text) The 6107 is a halogen-quenched end-window GM tube featuring a thin mica window, making it sensitive to alpha, beta, and gamma radiation. Despite being over 80 years old, examples of the 6107 have been found in working order. In testing, they demonstrate stable operation at approximately 750 volts, with strong, clean pulse responses even to weak alpha emitters such as americium-241. In one instance, tubes achieved in excess of 20,000 counts per minute (CPM) when exposed to Am-241 at a 3–4mm distance, a testament to the durability and craftsmanship of the era. (AI generated text) Specs:
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Some more info on these tubes here.
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Energy compensated, Halogen quenched, Gamma sensitive Geiger–Müller tube with compensating filter and long life artificial background. The datasheet linked here is for the ZP1301, but states 'also available with long life artificial background as ZP1302. This tube lives in a Plessey PDRM 82, as shown in one of the pictures. It was removed for photographing.' Specs:
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