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Viewing 12 posts - 1 through 12 (of 12 total)
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  • July 9, 2018 at 12:05 pm #5905
    Yves Dubois
    Participant

    Thank you for the tip Wolferl.
    I will try that and keep you informed.
    And sorry for the wrng link

    July 12, 2018 at 6:58 am #5917
    Yves Dubois
    Participant

    I open the enclosure take the board out but did not see anything abnormal.
    Still giving me weird readings.

    July 12, 2018 at 9:51 pm #5936
    Radu
    Keymaster

    Thanks for your help on this @Wolferl,

    It is possible the tube goes into oscillation due to a misbehaving capacitor, called “the compensation capacitor”. Normally all A3 units have it set for 150pF, linked on the type of Geiger tube used (SI29BG), but in this case the value should be bigger to prevent these oscillations that result in high counts.

    Either this, or the tube is faulty going in avalanche (unlikely).

    You can either send the unit back so I can have a look at it, or change the capacitor yourself based on my indications. I’ll be happy to accommodate any of the two options.

    Attachments:

    1. compensation_capacitor.jpg

    July 13, 2018 at 6:44 am #5939
    Yves Dubois
    Participant

    Thank you all,

    As my A3 was pen board and one of the wire that rely the sensor to the board was cut.
    After re-solder I pass a 300° rework air blow lightly on the card specially in the middle under the Geiger tube.
    Since, it seems to rework.

    Crossing the finger 🙂

    July 13, 2018 at 6:46 am #5940
    Yves Dubois
    Participant

    Correction
    As my A3 was open board and one of the wire that rely the sensor to the board was cut.

    July 13, 2018 at 6:57 am #5941
    Yves Dubois
    Participant

    I apply the heat exactly where Radu point on the picture he submit.
    By the way, the black wire that was cut maybe also the cause.
    I couldnt say if it was cut before or after the opening of the casing.

    July 13, 2018 at 10:16 am #5944
    Yves Dubois
    Participant

    Everything works fein
    The two pic below represent the graphs of the day for my two outside unit rads and temp

    Attachments:

    1. compare.png

    2. compare-temp.png

    July 13, 2018 at 10:17 am #5947
    Yves Dubois
    Participant

    They are positioned east and west

    July 13, 2018 at 3:32 pm #5949
    Yves Dubois
    Participant

    Hi

    Thanks to you to for helping
    Have a great day.

    Cheers
    Yves

    July 15, 2018 at 10:18 am #5955
    Yves Dubois
    Participant

    Hello all,

    It start again this morning at 8:28 it passes from 0.20µSv/h to more than 9000µSv/h
    And the curve is straight til 10:40 then it drop down to “normal” background level around 0.14
    It is very ennoying because such readings is not representing the reality at all and should not display on UradMonitor network.
    If Radhoo is around , I dont know what to do?

    Attachments:

    1. voltage-graph.png

    2. Rads-15-07-18.png

    July 15, 2018 at 11:08 am #5958
    Yves Dubois
    Participant

    I have a guess.
    It is maybe due to the heat inside the box that disturb something.
    At 12:00 today the exhaust indicate 35.6° aand the ambient temp was 30°
    At 08:30 the ambient temp was escalating from 30 to 34°that mean at that time the exhaust air from the board might have be 40°
    I decide to move the A3 to a new location from screwed to the inside part of the wooden shutter to a cool wall.
    Will see

    Attachments:

    1. IMG_3768.jpg

    2. IMG_3772.jpg

    3. IMG_3773.jpg

    August 8, 2018 at 9:29 am #5992
    Radu
    Keymaster

    Hello @ybm,

    The unit was fixed, I replaced the compensation capacitors and two transistors in the counting circuit.

    The tube itself was OK!

    Soon to be shipped back!

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