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KK4NEF
USA
1 Posts |
 Posted - 10/16/2017 : 10:53:58
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| Has anyone ever modified this unit to include an exterior connector (BNC/SMA) to allow for an external GM tube or probe? Just ordered a new GMC-320+ today and thought it would be cool to add that. |
Austin Jewsbury
KK4NEF
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| Reply #1
flukeguy
USA
13 Posts |
Posted - 10/16/2017 : 13:38:28
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I have installed an RCA phono connector as it was the shortest that I could fit in there. I then use a phono to BNC adaptor to my SBT-11 probe. Always works fine and can still use then internal tube
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--Terry |
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| Reply #2
ullix
Germany
1110 Posts |
Posted - 10/17/2017 : 05:01:14
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It doesn't need "high quality" cables, whatever this may mean. Even some plain lab cables will do.
But be aware of capacitance issues, as discussed here http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=4598
However, unless you go for very high count rates, even poor cables, i.e. such with high capacity, will not have a big impact.
Just for capacity issues don't make the lines too long, e.g. less than 1m. If you need longer, carefully look at capacity. |
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| Reply #3
the_mike
Switzerland
53 Posts |
Posted - 10/18/2017 : 08:43:49
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Hi Terry
are you using both tubes at once, or can you switch the tubes? |
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| Reply #4
flukeguy
USA
13 Posts |
Posted - 10/18/2017 : 09:03:32
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Hi Mike,
I just leave both tubes hooked up. I'm sure that the background readings are an approximate sum of both tubes.
--Terry |
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External GM Tube
