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 Light-Sensitivity of a GMC Counter - Yet again!
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Reply #1

Damien68

France
516 Posts

Posted - 11/30/2020 :  11:08:13  Show Profile  Reply with Quote
sure that EMP can induce parasitic peak current in proportion of the area of the loop formed by two wires and this can result in a surge voltage.
but in normal environement the energies involved are very low and do not constitute particular risks for this kind of devices which in any case are already protected against surges (especialy in relation with electrostatic discharges wich constitutes a real risk du to his higher energy level).

to undertand this you can take a look around Biot-Savart law

Mean Time Between Failures (MTBF) of a device depends mostly on the components used in the device and also of how they are used. This can vary greatly also each device has its own MTBF which is only a statistical tool.

there can be a correlation between the MTBF of a device and the nature of its enclosure, but if it's the case, it's just a correlation and not a established cause to effect relationships.

for the automotive industry, there are particular standards because it's a strong and aggressive environment (a lot and strong overvoltages, EMI, electrostatic discharges, high di/dt ... ) so the components that can be used in this industry must meet specifics standards.

So for example automotive ignition control unit or automotive on-board computer are super shielded because in this case we should considere EMP (because of the harsh environment), but for GM counter on a desktop EMP can't affect his MTBF.

Mastery is acquired by studying, with it everything becomes simple

Edited by - Damien68 on 12/01/2020 01:38:35
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Reply #2

37TS

Italy
4 Posts

Posted - 12/15/2020 :  16:25:30  Show Profile  Reply with Quote
New here but with some background.

Maybe I didn't read everything properly but it seems that no one mentioned the stimulated emission of highly ionizing radiation.

It's a common phenomenon and even led lights are subjected to it.
Electrons, after all, are considered radiation too and they get emitted by most filaments/compounds/semiconductors (among other types other ionizing radiations) when stimulated with electricity at varying conditions of temperature and pressure.

I own a GMC-300E V4. I did not tear it down yet but I can clearly see that it has a clear, transparent tube inside.

I bought a 10 watts UV torch with a diode that has an UV-C pass filter on it (365 nm) and it blasts the counter with 12 uSv/h at 2000 CPM, per second!!!
I also have an halogen lamp, 250 watts, super hot, you cannot even watch it directly, yet the counter barely touches 14 CPM at 0.08 uSv/h with it.

How come?

Basically, you really are detecting beta emission from those flashlights/sources (even the sun).

Read more about the stimulated emission of x-rays to know more about the physics behind the phenomenon, there's a lot to learn on the subject.

That's my take on it.

Clicking like there's no tomorrow!!! XD

Edited by - 37TS on 12/15/2020 16:27:05
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Reply #3

Damien68

France
516 Posts

Posted - 12/16/2020 :  22:50:58  Show Profile  Reply with Quote
quote:
Originally posted by 37TS
I bought a 10 watts UV torch with a diode that has an UV-C pass filter on it (365 nm) and it blasts the counter with 12 uSv/h at 2000 CPM, per second!!!
I also have an halogen lamp, 250 watts, super hot, you cannot even watch it directly, yet the counter barely touches 14 CPM at 0.08 uSv/h with it.

How come?




the 365nm photons of UV light have a sufficient level of energy to detach an electron from the potassium atoms present in the glass of some GM tube, this by a Photoelectric effect.
it is a quantum effect, what is primordial is not the overall energy of light beam but the energy transported by each photons (so function of the light wavelength), and only photons with an energy level higher than a characteristic value named 'Work_function' will be able to extract an electron from potassium.
halogen lamps radiate more in the infrared and visible light and very little in UV, so the biggest part of photons emitted by the halogen lamp do not have the energy level required to detach an electron from potassium atome by photoelectric effect.

https://en.wikipedia.org/wiki/Work_function.

it is true that we could speak about beta radiation but in this case it is emerging on the tube caused by photoelectric effects, in this experimental conditions beta radiation doesn't come intrinsically from the light source.

Mastery is acquired by studying, with it everything becomes simple

Edited by - Damien68 on 12/18/2020 23:44:59
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Reply #4

GreenPhlash

USA
1 Posts

Posted - 01/17/2021 :  13:47:19  Show Profile  Reply with Quote
quote:
Originally posted by ullix

There is an elaborate post on the topic of light-sensitivity of the M4011 tubes done almost 3 years ago: http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=4540

But the effect is back! And it brings a new surprise.

Back then the M4011 tubes were made of clear glass. As a consequence, GQ modified the tubes by covering them with a black, plastic-like cover. Presumably assuming that the black cover would absorb all light .....



I had been noticing that my 320 Plus with a clear glass M4011 tube over the last 5 months or so was getting higher background radiation readings. I played around with it, aimed the back of the unit towards the sun and saw readings jump to over 2000. After reading through this post [Thanks ullix !!] I tried to first paint the tube with black acrylic paint, but that stopped all readings, so I removed the paint, put on black electrical tape over the tube and now my readings are back to once they used to be. Odd. Do the other tubes that GQ sells fit into the 320?
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Reply #5

ullix

Germany
602 Posts

Posted - 01/18/2021 :  02:21:01  Show Profile  Reply with Quote
@GreenPhlash: Thanks for posting your observation. Perhaps there are more people realizing that their devices have a light sensitivity problem.

The puzzling thing is that not all tubes, not even clear glass tubes, are light sensitive. I have some, which, to the best of my abilities, I have shown that they are not. And then there are tubes which are, despite having a black coating, as discussed in this present topic.

The problem is not to explain the physical base for light sensitivity. The problem is to explain why this does NOT apply to some tubes. And this is the question which makes it attractive to a physicist ;-)

Re alternative tubes: GQ seems to have moved away from using the M4011 - be it clear glass or blackened - towards tubes from the Jxyz type. Some of those tubes are mechanical and electrical drop-ins. When you have very low cost devices, you are likely to find those tubes, see e.g. my article https://sourceforge.net/projects/geigerlog/files/Articles/GeigerLog-Radiation-v1.1%28CAJOE%29-Support-v1.0.pdf/download

No announcement by GQ, so we can speculate that the move is done just because they are cheaper, not because of technical superiority. As long as the cause for the light sensitivity is not understood there is little hope that just another manufacturer makes a difference.

The Russian SBM20 tubes (and similar ones) have a steel housing, so light should not be an issue. They can be fitted into the GMC housings, but it takes some mechanical and soldering work. Electrically they can be considered drop-in products. But to my knowledge, there is no production of new tubes; you only get old supply from cold-war times. Those are still OK but understandably not a good base for a manufacturer of new devices.

I have used the SBM20 but only with external wiring, like shown here: http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=4571

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Reply #6

WigglePig

27 Posts

Posted - 01/18/2021 :  03:39:49  Show Profile  Reply with Quote
Now, this topic has greatly interested me for a number of reasons, chiefly that systematic uncertainties can often cause all manner of problems with detection and measurement systems. Due to this interest I have spent much of the weekend studying the operation of GM tubes and how their design and materials, especially the fill gases, affect their behaviour; there is a considerable amount of relevant materials available all arounf the Web which are useful in this regard.

Incidentally I have also found, completely by accident, about the products and activities of a company which has a factory near to where I live and how they have been involved in the development of detector tubes of various type. That is an aside, however.

The general operation of GM tubes is rather interesting in regards to the issue of light sensitivity.

What I suspect is that there are multiple mechanisms in play in different situations and these are difficult to isolate with the equipment we have.

Firstly, the GM tube will trigger on *any* ionising event of sufficient energy which interacts with the tube. This can be (in the case of the M4011 tube and similar) beta, gamma or X-rays from a "traditional" source of said, but this can also be caused by UV light of sufficient energy; this can be by generating emissions in the conductive outer of the tube coating or by direct interaction with the fill gas. This is precisely how the avalanche effect inside the tube which leads to a detectable pulse occurs; generation of UV photons which go on to ionise further gas in the tube.

Secondly, some sources of (especially) UV light generate ionising events within their junctions, sometimes by direct emission but also by UV ionisation in other materials. In fact, a white light LED actually generates UV and this UV then causes the white phosphor mixture to fluoresce. The UV action can cause emission of beta particles from the LED itself but can also exit from the luminere and cause ionisation in and around the GM tube in turn.

These observations have been arrived at by examining the descriptions and results of various tests done by a number of persons around the World, including persons on this forum.

So, in summary, I would not be surprised to see elevated counts from Sunlight, or from LED lights (either UV or white) but I would NOT expect to see such behaviour from a "normal" incandescent lamp, however bright it may be.
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Reply #7

Damien68

France
516 Posts

Posted - 01/18/2021 :  04:04:30  Show Profile  Reply with Quote
quote:
Originally posted by WigglePig
So, in summary, I would not be surprised to see elevated counts from Sunlight, or from LED lights (either UV or white) but I would NOT expect to see such behaviour from a "normal" incandescent lamp, however bright it may be.



with ullix we looked for, see above on this post,
ionization would be initiated by a photoelectric phenomenon by light (sun, UV, led, ...) on components of the glass of the GM tube by releasing an electron.
some tube glass would contain potassium others not. which will explain why some tubes are sensitive and others not.

Mastery is acquired by studying, with it everything becomes simple

Edited by - Damien68 on 01/18/2021 04:06:12
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Reply #8

WigglePig

27 Posts

Posted - 01/18/2021 :  04:12:10  Show Profile  Reply with Quote
quote:
Originally posted by Damien68

quote:
Originally posted by WigglePig
So, in summary, I would not be surprised to see elevated counts from Sunlight, or from LED lights (either UV or white) but I would NOT expect to see such behaviour from a "normal" incandescent lamp, however bright it may be.



with ullix we looked for, see above on this post,
ionization would be initiated by a photoelectric phenomenon by light (sun, UV, led, ...) on components of the glass of the GM tube by releasing an electron.
some tube glass would contain potassium others not. which will explain why some tubes are sensitive and others not.



The glass does not need to contain potassium to generate this effect, the metallised coating inside the tube is sufficient. The differences of behaviour of different tubes can be explained by differences in the fill gas composition, thickness and type of coating (if relevant) as well as any other differences. That a significant difference between the bahaviour of different parts of a tube which is identified as sensitive does indeed suggest that it is some indirect ionisation effect in these cases (the cathode connection being the most sensitive area suggests the cathode bonding lead is where the ionisation is occurring.

There is quite some discussion, as well as descriptions of operating mechanisms and patent details, on the subject of tubes being used as UV detectors and it is clear that the construction is generally very similar to GM tubes but just operating them in a different region of their characteristic curve(s).

Edited by - WigglePig on 01/18/2021 04:20:16
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Reply #9

Damien68

France
516 Posts

Posted - 01/18/2021 :  08:37:51  Show Profile  Reply with Quote
quote:
Originally posted by WigglePig
The glass does not need to contain potassium to generate this effect, the metallised coating inside the tube is sufficient. The differences of behaviour of different tubes can be explained by differences in the fill gas composition, thickness and type of coating (if relevant) as well as any other differences. That a significant difference between the bahaviour of different parts of a tube which is identified as sensitive does indeed suggest that it is some indirect ionisation effect in these cases (the cathode connection being the most sensitive area suggests the cathode bonding lead is where the ionisation is occurring.

There is quite some discussion, as well as descriptions of operating mechanisms and patent details, on the subject of tubes being used as UV detectors and it is clear that the construction is generally very similar to GM tubes but just operating them in a different region of their characteristic curve(s).



possible,
It would be necessary to make more precise tests and to illuminate only certain areas.
I don't have any light sensitive tubes.

what is certain is that there are chemical elements in the sensitive tubes which disappear in the insensitive tubes.

but anyway for M4011 it's a mess, on ebay sellers specify that: "the tube can be sensitive to light".
not "sensitive" nor "non-sensitive" but "can be sensitive".

more or less like: buy me one to know if you are lucky, but you will have been warned

Mastery is acquired by studying, with it everything becomes simple

Edited by - Damien68 on 01/18/2021 11:18:31
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Reply #10

Damien68

France
516 Posts

Posted - 01/18/2021 :  09:12:28  Show Profile  Reply with Quote
quote:
Originally posted by ullix
The Russian SBM20 tubes (and similar ones) have a steel housing, so light should not be an issue. They can be fitted into the GMC housings, but it takes some mechanical and soldering work. Electrically they can be considered drop-in products. But to my knowledge, there is no production of new tubes; you only get old supply from cold-war times. Those are still OK but understandably not a good base for a manufacturer of new devices.


Quarta-Rad aka Radex still uses the SBM-20 even on these recent products but it's a Russian company.
it is sure that it is not easy to find low cost and reliable supplier.


Mastery is acquired by studying, with it everything becomes simple

Edited by - Damien68 on 01/18/2021 10:02:29
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Reply #11

Senketsu

Poland
18 Posts

Posted - 01/29/2021 :  19:06:23  Show Profile  Reply with Quote
SBM-20-1 are still produced, I have several dosimeters equipped with the new SBM-20-1 (they are very nice, not as tarnished as the old ones).

I will check on my GMC-500/500 + and 600 how they react to light

GC: GMC-300E plus, GMC-500, GMC-500 plus, GMC-600, Exploranium GR-110G, Terra MKS-05 bluetooth, DoseRae 2, RadiaScan 701A, Automess 6150AD6, Soeks Qantum, PRM-9000, Radex Obsidian, Radex RD1008, MKS-03SA
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Reply #12

ullix

Germany
602 Posts

Posted - 01/30/2021 :  01:14:55  Show Profile  Reply with Quote
quote:
SBM-20-1 are still produced,

@Senketsu: this is interesting news! can you give links to manufacturer, supplier, shops?

It would be a major surprise if steel-housed tubes were also light-sensitive!

Edit: I just realize your footer to the post. That is an impressive list! Does it mean that you have all of those counters?

If so, which of them have an output to allow logging from the counter, and which have internal memory to allow stand-alone data-collection?

Edited by - ullix on 01/30/2021 01:18:28
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Reply #13

Senketsu

Poland
18 Posts

Posted - 01/30/2021 :  05:08:36  Show Profile  Reply with Quote
@ullix, Thank you, but this is only a small part, I currently have 68 dosimeters/radiometers, I plan to take a photo of the my full collection soon, but I am currently waiting for Mazur PRM-8000, PRM-7000 and RD1212-BT

Saving measurement data from my collection: Mazur PRM-9000, Gamma Scout, RadiaScan 701A, DoseRae2, Radex Obsidian, Soeks Quantum
Communication with pc and recording of measurement data: Radex RD ONE, MiniTrace S-5...

I would have to check out the entire collection.

Will the LED torch light be suitable for testing? I shone the flashlight at the back in the hole where is M4011 tube (covered with something black) - it did not increase the CPM in 500/500+ and 600 (sbt-11 mica window).


GC: GMC-300E plus, GMC-500, GMC-500 plus, GMC-600, Exploranium GR-110G, Terra MKS-05 bluetooth, DoseRae 2, RadiaScan 701A, Automess 6150AD6, Soeks Qantum, PRM-9000, Radex Obsidian, Radex RD1008, MKS-03SA
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Reply #14

ullix

Germany
602 Posts

Posted - 01/30/2021 :  09:07:58  Show Profile  Reply with Quote
quote:
@ullix, Thank you, but this is only a small part, I currently have 68 dosimeters/radiometers, I plan to take a photo of the my full collection soon, but I am currently waiting for Mazur PRM-8000, PRM-7000 and RD1212-BT


Good Lord! I think many people would be interested in comparisons/observations with all these devices. I want to encourage you to write something up - even if only few devices are covered - and I would very much like to present a copy of this on my GeigerLog sourceforge site!

May I remind you of my question re manufacturer/supplier etc for the SBM-20-1 tube?

quote:

Will the LED torch light be suitable for testing? I shone the flashlight at the back in the hole where is M4011 tube (covered with something black) - it did not increase the CPM in 500/500+ and 600 (sbt-11 mica window).

It depends. There are tubes, even clear glass tubes of the M4011 type, which do not exhibit light sensitivity, no matter what one tries, and then we found a blackened M4011 tube, where you had to shine the light onto a specific spot, which turned out to be one where the layer of lacquer was a little bit damaged. There is no explanation for the fact that some clear glass tubes are sensitive to light and others not.

So far the white light of an LED flash light had been enough to demonstrate light sensitivity, but if you can use at least a blue light LED, and even better, a UV light LED/Flash Light, you have a better chance of finding something.

Blue light from any source using the incandescent principle or even using a halogen lamp, e.g. using a blue (glass) filter, will probably not be helpful.


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Reply #15

Senketsu

Poland
18 Posts

Posted - 01/30/2021 :  13:27:01  Show Profile  Reply with Quote
No problem, I'll always be happy to help! I have a blog, youtube channel, instagram account :)

Unfortunately, I don't know where Soeks buys new Geiger tubes, but in my Ecovisor F4 it is completely new and recently produced, I can contact Soeks directly and ask.

Today I will use a UV flashlight and a powerful flash (as a photographer I have strong reportage lamps).

Flash lamps generate an increase in indications in the Smart Geiger and Smart Geiger Pro semiconductor meters (I used to take photos of smart Geiger and I noticed that).

GC: GMC-300E plus, GMC-500, GMC-500 plus, GMC-600, Exploranium GR-110G, Terra MKS-05 bluetooth, DoseRae 2, RadiaScan 701A, Automess 6150AD6, Soeks Qantum, PRM-9000, Radex Obsidian, Radex RD1008, MKS-03SA

Edited by - Senketsu on 01/30/2021 13:28:09
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Reply #16

ullix

Germany
602 Posts

Posted - 01/31/2021 :  02:04:16  Show Profile  Reply with Quote
quote:
I can contact Soeks directly and ask.
That would be great!

quote:
Flash lamps generate an increase in indications in the Smart Geiger and Smart Geiger Pro semiconductor meters (I used to take photos of smart Geiger and I noticed that).
I am not surprised, I reviewed the Smart Geiger Pro here https://sourceforge.net/projects/geigerlog/files/Articles/GeigerLog-Review%20Smart%20Geiger%20Pro%20%28SGP-001%29-v.1.0.pdf/download

This device is basically a solar cell, meant to convert photons into electrical signals. In my device the insulation against light was a copper foil. If that isn't perfectly tight, you'd see light effects. However, my device did not show any response to light (perhaps a matter of intensity; your photo lights may be stronger?).

The enticing aspect of these devices is that the electric impulse is in principle proportional to the energy of gamma quanta and thus could serve as a spectrometer. Unfortunately, my trials failed completely.

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Reply #17

Senketsu

Poland
18 Posts

Posted - 01/31/2021 :  04:45:28  Show Profile  Reply with Quote
The Smart Geiger is not bad, but it has many disadvantages and it also reacts to shock...

Radex Obsidian makes a pretty good spectrum and works with BecqMoni :)

I need to test GeigerLog, it seems to be a great app! Will it work with my Gamma Scout too?

I have performed the test, my GMC-500 and 500+ (both are v2) do not respond with an increase in radiation indications, even to a strong flash flash.

I have a Geiger STS-5/SBM-20 and STS-6 GM counter, I can connect them to a universal radiometer and also perform a light tightness test

GC: GMC-300E plus, GMC-500, GMC-500 plus, GMC-600, Exploranium GR-110G, Terra MKS-05 bluetooth, DoseRae 2, RadiaScan 701A, Automess 6150AD6, Soeks Qantum, PRM-9000, Radex Obsidian, Radex RD1008, MKS-03SA

Edited by - Senketsu on 01/31/2021 04:46:54
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Reply #18

ullix

Germany
602 Posts

Posted - 01/31/2021 :  07:46:55  Show Profile  Reply with Quote
Note: a post of mine has disappeared. Wonder if it will resurface. So, I repeat:

quote:
Radex Obsidian makes a pretty good spectrum and works with BecqMoni :)
The Obsidian seems to be unavailable in the EU. Apparently the detection is based on scintillation. They are remarkably quiet on their website re the technology. Do you know if it is Sodium-Iodide? Cesium-Iodide? Other?

quote:
I need to test GeigerLog, it seems to be a great app! Will it work with my Gamma Scout too?
GeigerLog does support downloading from the Gamma-Scouts. But the "live" mode of the 'online' version is not yet supported; I simply had no access to a counter to test. If you have one of those, and are willing to support some testing, it could be implemented.

quote:
I have performed the test, my GMC-500 and 500+ (both are v2) do not respond with an increase in radiation indications, even to a strong flash flash.
Good for you!
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Reply #19

Damien68

France
516 Posts

Posted - 02/01/2021 :  00:27:20  Show Profile  Reply with Quote
quote:
Originally posted by ullix
The Obsidian seems to be unavailable in the EU. Apparently the detection is based on scintillation. They are remarkably quiet on their website re the technology. Do you know if it is Sodium-Iodide? Cesium-Iodide? Other?


scintillation with solid state photomultiplier, but the sensor size is really small for scintillation.
on youtube we find videos, some favorable others not.

Mastery is acquired by studying, with it everything becomes simple
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Reply #20

EmfDev

1438 Posts

Posted - 02/01/2021 :  11:46:25  Show Profile  Reply with Quote
Hi Damien, thank you for sharing the sensor, I will let our team know and see if we can use it :)
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Reply #21

Damien68

France
516 Posts

Posted - 02/02/2021 :  00:53:45  Show Profile  Reply with Quote
I delete my previous post by error, sorry for that.
just to call back references:
Sensor is from "First Sensor compagny" is 100 mm2 PIN Photodiode + CsI:Tl scintillator
https://www.first-sensor.com/cms/upload/datasheets/X100-7_THD_3001447_3001448.pdf


distributed by Mouser.

Interesting experimentations of Photodiodes and Scintillator with electronic detection stage basic explainations:
h**p://physicsopenlab.org/2018/07/08/si-pin-photodiode-plus-with-csa-sa/
h**p://physicsopenlab.org/2018/09/23/photodiode-and-csitl-scintillator-with-micod-csa-sa/

Mastery is acquired by studying, with it everything becomes simple

Edited by - Damien68 on 02/02/2021 06:47:59
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Reply #22

Senketsu

Poland
18 Posts

Posted - 02/03/2021 :  12:51:03  Show Profile  Reply with Quote
@Ullix Yes, they are most familiar to me.

Obsidian is hard to get, but I think it will also be available in the EU (currently available in the US and Russia)

Tomorrow I will pick up the GMC-300E Plus and also check the reaction of the M4011 to light (there will be no black coating).

I am currently writing a review of the GMC-500 model and additionally decided to discuss each option available in the menu (The most configurable dosimeter on the market)


GC: GMC-300E plus, GMC-500, GMC-500 plus, GMC-600, Exploranium GR-110G, Terra MKS-05 bluetooth, DoseRae 2, RadiaScan 701A, Automess 6150AD6, Soeks Qantum, PRM-9000, Radex Obsidian, Radex RD1008, MKS-03SA

Edited by - Senketsu on 02/03/2021 12:52:22
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Reply #23

Senketsu

Poland
18 Posts

Posted - 02/04/2021 :  05:54:35  Show Profile  Reply with Quote
GQ GMC-300E Plus Re 4.50 is currently testing (newer firmware available?). The M4011 counter is not black painted, and yet it does not respond to the strong flash of a reporter's lamp applied to the holes at the bottom of the dosimeter

M4011 production 2019 y

GC: GMC-300E plus, GMC-500, GMC-500 plus, GMC-600, Exploranium GR-110G, Terra MKS-05 bluetooth, DoseRae 2, RadiaScan 701A, Automess 6150AD6, Soeks Qantum, PRM-9000, Radex Obsidian, Radex RD1008, MKS-03SA

Edited by - Senketsu on 02/04/2021 06:03:42
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Reply #24

cynoclast

USA
3 Posts

Posted - 03/11/2021 :  22:34:05  Show Profile  Reply with Quote
I've been having some anomalous readings with my GMC-300E+ so I did some digging and found this thread.

Out of curiosity shined a very bright headlamp I own into the holes on the back right onto the tube and got this after just a minute or two:


Light sensitivity (SER via LED) is for sure a thing with at least some of these.

Should I try and return the unit or get a new Mueller tube?

I'd like a Radiation detector that doesn't constantly false-alarm.
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Reply #25

ullix

Germany
602 Posts

Posted - 03/12/2021 :  00:46:47  Show Profile  Reply with Quote


Welcome to "Groundhog Day in Light-Sensitivity County"! You may have missed this more recent topic on the matter: http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=9544?

In this topic EmfDev opinions that the tube is defect and suggests to email support and you will get a "good" tube.

So you did not open the case, but had kept the back cover on, just as EmfDev said is needed for proper operation. Hmm, does not seem to help.

To replace the tube you will have to remove the back cover anyway, so you can do it now. What type of tube do you have: M4011, J305, other, clear glass, blackened glass?

I now have a total of 6 tubes coming from GQ. Of those 3 are light sensitive. That is 50%!

What are the chances of me getting 50% "defective" tubes if that is an exception among thousands (?) of tubes? My guess, if more people check for light sensitivity, we'll get a lot more news on "defective" tubes.


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Reply #26

cynoclast

USA
3 Posts

Posted - 03/12/2021 :  01:09:18  Show Profile  Reply with Quote
quote:
Originally posted by ullix



Welcome to "Groundhog Day in Light-Sensitivity County"! You may have missed this more recent topic on the matter: http://www.gqelectronicsllc.com/forum/topic.asp?TOPIC_ID=9544

In this topic EmfDev opinions that the tube is defect and suggests to email support and you will get a "good" tube.

So you did not open the case, but had kept the back cover on, just as EmfDev said is needed for proper operation. Hmm, does not seem to help.

To replace the tube you will have to remove the back cover anyway, so you can do it now. What type of tube do you have: M4011, J305, other, clear glass, blackened glass?

I now have a total of 6 tubes coming from GQ. Of those 3 are light sensitive. That is 50%!

What are the chances of me getting 50% "defective" tubes if that is an exception among thousands (?) of tubes? My guess, if more people check for light sensitivity, we'll get a lot more news on "defective" tubes.






I think the ? at the end broke your link but I found the thread anyway (REST developer FTW). I fixed it in my reply.

I did actually open the case at one point and tried to wipe down the tube - suspecting radioactive particles adhering to it - with a microfiber (lens cleaning) cloth to no avail. I don't have the back cover off at the moment, so I can't tell you the exact model, but the tube is clear glass. Although, from my reading that doesn't seem to matter as it seems some obscured tubes still react to light when they shouldn't.

Unfortunately(?) I ordered and received my unit through amazon so I don't have a GQ order number or anything, but I'll reach out to EmfDev or customer support soon.

Thank you so much for reply so quickly though! I wasn't expecting a response any time soon.
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Reply #27

Damien68

France
516 Posts

Posted - 03/12/2021 :  01:13:39  Show Profile  Reply with Quote
if it affects more than 3 or 4% it is no longer marginal

Mastery is acquired by studying, with it everything becomes simple
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