| T O P I C R E V I E W |
| and_kom |
Posted - 09/30/2012 : 01:47:05
Can anyone confirm that russian tube SMB-20 is more sensitive than m4011 tube? |
| 8 L A T E S T R E P L I E S (Newest First) |
| ullix |
Posted - 05/26/2019 : 01:06:40
You find a comparison between an SBM20 and a M4011 here:
http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=4571&SearchTerms=ullix,sbm20,m4011
My Conclusion:
quote:
Overall, the SBM20 has the same background as the M4011, but is 40+% more sensitive to counts as long as the source has a strong beta component. Whether the difference extends to gamma is not known and cannot be told with these experiments.
I think the installation of a SBM20 into a 300 housing, while possible, is not worth the hassle!
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| Franglish9265 |
Posted - 05/25/2019 : 10:46:05
I recently verified that the SBM-20 outperforms the M4111 tube. I read 500 cpm from my vaseline glass cat paperweight, with an SBM-20 tube, but only got 370 to 400 cpm from the M4111 tube, under the same conditions. |
| Nudnik |
Posted - 05/21/2015 : 02:40:56
quote:
Originally posted by ska
The real problem is find a good sbm-20 tube, It's really tricky.
GM tubes are not degrading by age. A 50 year old but unused russian tube will still work as specified. You probably need to remove corrosion from the contacts, depends on the storage conditions.
GM tubes degrade by detecting.
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| and_kom |
Posted - 10/06/2012 : 08:48:19
I am from Ukraine (ex. USSR) and it's not a big problem to find SBM-20 there. It costs 10-15$ in average there...
I've got one today. First tests showed it seems to be ok. |
| ska |
Posted - 10/03/2012 : 05:16:55
The real problem is find a good sbm-20 tube, It's really tricky. |
| and_kom |
Posted - 10/03/2012 : 02:26:52
Found some tubes info: https://sites.google.com/site/diygeigercounter/gm-tubes-supported
quote:
SBM-20 - The quintessential Russian tube. Lower priced, and more sensitive to beta and gamma than most. This is still one of my favorite all around beta gamma tubes. The STS-5 is pretty much the same tube and may be cheaper.
M4011 - Glass tube made (new) in China. Claimed to be more sensitive than the SBM-20. Although I once got high readings, it now seems similar to the SMB-20. I'm not overly impressed - especially at it's price. IMO the claims for it's sensitivity are exaggerated.
The comparision shows that SBM-20 is slightly sensitive than m4011.
quote:
Initially, the M4011 appeared to be more sensitive than the SBM-20. However, I couldn't repeat this result. I'm not sure what happened - something with the tube? To rule out any change in the counter, I simply changed tubes to the SBM-20 and repeated the SBM-20 test, which was consistent with the previous results. I have no choice but to revise my previous results with what are now more consistent readings. The tubes operating range is 380-450V, and I ran the tube at 450V for the test above. (In the dark, you can see a faint orange glow inside the tube when it's firing.)
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| ZLM |
Posted - 10/02/2012 : 22:05:41
Both SMB-20 and M4011 are in same sensitivity range. |
| ska |
Posted - 09/30/2012 : 06:55:20
According to my tests, SBM-20 is actually more sensitive in slightly radioactive object, but I'm still looking into. I'm searching for more slightly radioactive objects.
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