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Frank
USA
39 Posts |
 Posted - 10/15/2013 : 16:01:59
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| Perhaps I am missing it somewhere here, but just got a 280 today and noticed inside that there are 2 adjustable pots, and some pictures I have seen show one. I figured the out the pot at the end of the tube near the battery was for voltage adjust, whats the other one for? Also, is there a manual for this somewhere? Was trying to figure out a safe voltage to set the 4011 tube too..Thanks Frank |
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| Reply #1
Frank
USA
39 Posts |
Posted - 10/15/2013 : 16:47:44
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| Geez, what a difference. I have (2) 200 models and both click away averaging about 15 to 20 clicks per minute, the 280 I just got, same tube type, and its been single number readings since I turned it on... is this normal? |
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| Reply #2
ZLM
1261 Posts |
Posted - 10/15/2013 : 21:29:21
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The another pot is for LCD contrast.
The back ground reading lower than 10 is OK since it is not a fixed reading.
Try to do a Factory Reset to make sure all software parameters are not out of range. |
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| Reply #3
Frank
USA
39 Posts |
Posted - 10/16/2013 : 06:38:52
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Correction on the background reading I was getting. It was low compared to my 200 models running, but in my error. I had the tube in backwards, I couldn't find a - or + on the board at all, did a quick measurement and thought I had put it in the right now. Popped it out, turned it around and that was it, readings matching with my other units, clicking away now...  |
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| Reply #4
Frank
USA
39 Posts |
Posted - 10/30/2013 : 12:30:44
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| Ug, my 280 went nuts today. Was sitting in my truck and was reading normal background levels, ~20cpm's for this area, then all of a sudden it started to climb, triggered the alarm that I had set at 40 since I figured double the norm would be a indication that it was climbing, but it just kept clicking away and was now over 115cpms and climbing still, needless to say, I was getting a little concerned since this was/is my first month or two owning a counter. Came back and check the sites, readings were averaging a but higher today here in the Northeast of the USA. Now at home and this thing is still going nuts, its not a constant click or continuous, but like putting it near something that is radioactive. Even here at home its going ballistic, and my other counters are not and they all have the same tube? Ideas? what is wrong? Frank |
Edited by - Frank on 10/30/2013 12:32:31 |
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| Reply #5
ZLM
1261 Posts |
Posted - 10/30/2013 : 13:30:58
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Did you have any mechanical shock to the counter?
Check the tube voltage, if the voltage is normal, then the tube may have some problem. |
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| Reply #6
Frank
USA
39 Posts |
Posted - 10/30/2013 : 17:50:29
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| Nope, its been running fine here in the shack, took it to work in a soft padded case, took it out at lunch in the truck and sat it on the dash. Was running for about 10 or so minutes, then it just started climbing. Went out at break two hours later and turned it on, did the same thing, went crazy on the readings and kept climbing. Got home and turned it on, been running fine, average is 20cpm's and been running for a few hours now. Can the battery, if it starts getting weaker cause this? other than that, can't think of anything. Or, is it possible where I work I was in fact spiking on something? :o Thanks Frank |
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| Reply #7
ZLM
1261 Posts |
Posted - 10/30/2013 : 20:46:57
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It must be something wrong at that time. If it happen again , check the voltage, if the voltage is OK, then the tube must be in a unstable condition.
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| Reply #8
Frank
USA
39 Posts |
Posted - 11/02/2013 : 04:14:12
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| geez, these units really are made to be used in their cases huh. I took one of my model 200's to work and had it running on the dash and decided to pop the cover and check out the circuit, etc and the thing went nuts when I put it near the window for more light as it was a cloudy day, was that the cosmic component I was picking up? you would have thought I put a radioactive item on top of it.. The 280 has been running fine since that one day when it climbed into the low 100 for cpm's, don't know what that was all about, but been normal since. Still wondering if anyone else had this happen to them, not just a raise in levels, but go from the norm of 20, then into the 100's, then back to norm hours later... Frank |
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| Reply #9
ZLM
1261 Posts |
Posted - 11/05/2013 : 10:37:59
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| All glass tube may be more sensitive to the sun light. Because of the UV and others. So, to get stable reading, always close the cover of the Geiger Counter. |
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GMC-280
