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v3ngence
USA
3 Posts |
 Posted - 03/21/2017 : 19:37:41
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Modded my GMC-320 with a SBT-11A, big increase in sensitivity!
I just wired it parallel with the stock tube. Looks like the circuit handles it fine.
I plan to make a probe handle and wire it with a bnc socket so it can be removed, that way I can keep the portability and connect the alpha probe when needed.
I think I'll keep the SBT-11A connected most of the time, the sensitivity is very good, plus the ionization flashes are so cool!
h**p://www.youtube.com/watch?v=_3MVGWw54bs
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| Reply #1
ZLM
1261 Posts |
Posted - 03/22/2017 : 09:45:17
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| Good. |
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| Reply #2
Distelzombie
Germany
202 Posts |
Posted - 03/23/2017 : 08:27:50
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| I did the same. But for the sake of some kind of calibration, I usually have the m4011 tube removed. How do you even calibrate two different tubes that spaced so much apart? |
GMC-300E+ V4.20 with sbt-11a alpha tube
My statements are "stuff-a-hobbyist-says" and not in any way professional. |
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| Reply #3
v3ngence
USA
3 Posts |
Posted - 03/23/2017 : 11:52:42
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I was wondering about calibration, it would be a pain to enter different values every time, so I think I'll leave the stock value and just measure some known sources with the SBT-11A so I can manually convert.
I think I'll wait until I make a long probe so the source won't affect the stock tube and alter the reading. |
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| Reply #4
Distelzombie
Germany
202 Posts |
Posted - 03/24/2017 : 08:20:36
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But that would always interfere with the reading. You cant be sure the stock tube is not picking up some gamma down there. And what would that even be useful for? You can and will measure background with the sbt tube as well and probably better.
I would add a switch to the internal tube too. |
GMC-300E+ V4.20 with sbt-11a alpha tube
My statements are "stuff-a-hobbyist-says" and not in any way professional. |
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| Reply #5
the_mike
Switzerland
53 Posts |
Posted - 03/25/2017 : 14:03:32
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I think it would be best if you could build in a "switch" to ..switch (poor choice of words sry) between the M4011 and the BNC...
edit: as you'd always pick up gammas with the built-in as described before
(anyway - pls post your plans etc as I, a non-electrician, want to do a similar project with my GMC320, but have no clue on how to do it ;-) |
Edited by - the_mike on 03/25/2017 14:04:18 |
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SBT-11A works in parallel with stock tube!
