@@blackfox_357chief4 When I made this video, it was summer here in the tropical region of China and the humidity was consistently over 85%, once winder arrived I found that without the loading resistor, the PSU voltage peaked pretty high and caused some ionization in the tube. It should also be noted that as part of an crowd-science experiment I am currently running, it seems that there is a lot of manufacturing variability in the PSU voltage of the GC-01.
I've watched a handful of your videos now, and want to thank you for the work that you put into them. In this one, you researched the company and also the white-box situation with this product. You did a thorough review and identified not only its shortcomings, but why. And as a bonus, how you worked around them. Your work is really over the top. And the post-production graphics and editing are really nice. Again, thank you.
I bought this p.o.s. and I dont know why I didn't look for video reviews first. Well, after being very disappointed by my purchase, I found this video, and it's making me feel so much better. I was worried that I was doing something wrong, but now all my suspicions are confirmed, and I've gotten to laugh a bit too! Lovely video!
Watched your video after I purchased one. Mine has the actual name on it. When I opened it it had the correct tube and no resistor. I think there may be several manufacturers using same case. But different internals. Thanks for the video.
I bought a device with a starting data of 2022. The seller contacted FNIRSI and said that his product was one of the newly produced versions. When I received the product, I opened it and looked inside, the battery had a production date of 24/07 and there was a Geiger Müller tube, M4011 tube, which is the same as the J321 but given a different name. The tests I conducted gave the same values as the J321. I think the manufacturer continues to produce the J321 "M4011" for FNIRSI.
Actually the factory owns the FNIRSI brand, so they have complete control over what tubes go into their branded products and what goes into the white label devices they sell separately.
This was very helpful and insightful. I saw this on Amazon and figured “what a great price”, but with all things cheap, you get what you pay for. I was wanting to know if this was worth the $70 on Amazon and thanks to you, you saved me from spending my hard earned money. I’m sure there is better out there that I’m not afraid to throw extra money into it, provided that it is a good product. Much appreciated
[Oct. 2024] I just bough mine and was indeed full of questions. After looking this video I opened it and yes, it is now "upgraded" with a shitty tube and cheap battery... thanks for the review
Congratulations on the excellent videos! After changing the GM tube the measured level (background too) flew into the sky. Fortunately, your new video about the firmware upgrade helped to fix the error. With your help, this GM counter has been a good, cheap instrument. THX!
Great review, i am strugling with the low sensitiviti and indeed i have the small tube. ordered the better tube now. Thanks! btw love the James May voice over.
@@TonyAlbus I also like yours - your business model is also particularly inspired. If I ever decide to make this channel pay for itself, then your chosen model is one that I would consider...
@@project-326 Thank you! ...its still hobby, but i like it a lot and that maybe shows... maybe it will be a business someday. thanks for the compliment.
I upgraded the crappy POS tube I had, to a J321, installed the RadPro software and upgraded the 1100mah battery to a 3500mah battery. *update* We are over 40hrs run time and counting now. Ps: the clips you need to solder on for the J321 tube are heavy duty fuse clips.
I ordered mine in december 2022 from TomTop and paid 39,59€ ( arround $43) after seeing the review done by IMSAI Guy. I didn't know there were (or are) 2 types of tubes for this meter. I just checked, and mine has the J321 tube. Thanks for sharing this information. Grtz
Such a good review , while watching it had feeling it comes from great and big youtuber, and now when I noticed 427 subs only , wondering why u don't have more. Where is issue.
so you mean that I am not a "great RUclipsr" then? 🤣🤣🤣 Not sure why the YT algo doesn't like me, probably because I routinely tell it to go and get f**cked...
Hi, I bought my FNIRSI GC-01 ne week ago via Amazon. I opend it up right away, and found a J321 tube in it. The date of production on the box is 2023-07-11 I gues I was lucky 😊 I totally like your suggestions to optimise this product. Thanks for this amaising reviev 👌🥰
Have the j321 tube came in a box dated may 2023 The boxes have dates of manufacture on the side Be easy to ask a seller when it was made It seems these earlier ones are 👍
I was really upset with mine. It was advertised with a big tube and the one i got was tiny. It couldn’t detect americium or soft xrays. I was irritated considerably
My original J321 FNRISI GC-01 has a 516 SMD resistor at R38. I bought an unbranded GC-01which had a J613 tube and no resistor at R38. Replacing the 613 with a 321 did improve but still seems a bit low compared to the original. I'll try adding a 516 SMD resistor at R38 and see if it improves.
I'm making a new video about the UV sensitivity of GM tubes (the second part) and a key aspect of the video is about the production tolerances of the power supplies used in products like this, so keep an eye out for that, it might help to set the loading resistor. I am going to be asking viewers that have detectors like this, to help with participating in some experiments - a sort of crowd sourced experiment. I am hoping that if enough people get involved, we can actually all learn something new. I hope you will be able to join in the experiment?
Re: the two tube "options". I received one of these this week from AliExpress and it has the (better) J321 tube, so maybe they did watch your video and took note. Secondly the tube's sensitivity to beta is limited by the plastic and rubber case. I do a demo ofcollecting radon decay products from the air in a house. When I presented the sample to the tube with the case open I got a much higher reading than when the tube was boxed up in the case. If this concerns any reader (especially since the radon demo is quite a polular thing to do) it would be possible to cut a long hole down the side of the box , or of course design a whole new box for it.
I have this FNIRSI GC-01, purchased around August/2023 and I can confirm they changed the tube for an even WORSE Version than the J631, the new one is half the size around 50mm long only. After watching your video, I ordered a J321 and will make this mod. thank you very much for the video! Edit: I've just found the model installed it's a J613.
Wow excellent review and upgrade , I have this unit and had no idea as to its inadequacies. I just took mine apart and confirmed I still have the J321 tube in mine. I must have old stock. The other caveat is there is a fastening screw underneath the small black label on the back that would’ve been nice if you had shown that has to be removed it’s hidden under the plastic black label peel it off and there’s a screw under there to remove. I know you know that but watching the video I don’t think anybody else knew that but thanks again for your great analysis of this product. Cheers.😊
I really appreciate the feedback, thank you! Perhaps the mechanical design has been updated in the version that I have, but I didn't need to remove that label to get the unit apart, as you can see in the tear down, there is no hole in the middle of the PCB to accommodate a 5th screw post. Just the 4 corner screws were removed and mine came apart. I looked at some other YT reviews with tear-down's and this was also the same (if you find any different, please post a link here). I have been asked to do a quick video to clarify the details of how I added the particle sounds, so I will be sure to include a part about this aspect, so you can see this on my version of the device. I have also had an extensive email exchange with the FNIRSI and their B2B commercial sales team confirmed that the factory that makes the branded products also manufacturers the unbranded ones (which is usually the case here in China) and FNIRSI even helps with this sales process and I assume they even earn a commissions as the white label versions are sold through their B2B team.
@@ralger I'm pretty confident that if there is a design change, it will have efected all of the versions. When did you get yours? FNIRSI confirmed that the change to the new tube was pretty recent. The sales guy said they changed over to the new GM tube（几个月前）which translates to a number of months ago (between 1 and 4, there is a different expression for numbers between 5 and 10).
@@ralger I just released an update for those wanting more info about how to add the particle clicks and I made a special effort to show the absence of the additional screw on my unit. Please take a look and let me know your feedback! It would be really strange if the tooling for this as changed, that is a very expensive change to make. When they changed to the new $hitty GM tube, they didn't even bother to update the PCB but just did some hand mods. Updating the PCB is pretty cheap in comparison!
I finally managed to do it! I successfully reviewed a product and didn't mention the Gamma Scout (PoS) once. What is a PoS? Its a Piece of $hit, of course...
I bought the device even after seeing this video because I don't mind tinkering. It's absolute trash. Even sitting on top of my ENTIRE BOX of spicy rocks, it only measured 1.03 uSv/h. My other cheap (and more expensive counters) scream. Lol Do you think changing out the tube to the J321 impacts the factory calibration?
@@AngryGopher612 Wow, that is true dedication to the art of "'tinkering"! There is no way to know for certain, but it looks like they just changed the tube and the firmware is the same as the old version. After I added the J321 to my device, the levels were a lot more normal (a little on the high side in some cases).
They must have changed the software also, to reflect the lower cps conversion into uSv/h. I have now changed my tube to the original J321 and it works, giving around 2.5 higher cps. But the uSv value is of course way to high. Of course the uSv is not accurate for anything, even on the original model, as its only calibrated for CS137, and even that, giving some errors due to some sensitivity even to hard Betas. But now its more the twice bakground. @@project-326
Hi, thank you for your review and these valuable information and insight! I bought this device about a year ago. It has the J321 tube in it I remember it because I was once in a hurry and dropped it and it stopped measuring. When I opened it, mine had no glue at the place of the tube so the tube moved after it hit the ground and lost contact. I moved the tube back in place and it works again. However Its a shame they have changed the manufacturing process, its misleading the customers.
I bought one. It had a cracked tube. They moved to a different tube design (one with wires and soldered leads like you mentioned in the video) that is just taped down at a weird angle so it fits inside the housing. Since mine had a cracked it worked even worse than the one you tested, as in not at all. I think you're 100% correct in your analysis.
I sold my Pudibei NR1050 and bought the Bosean FS5000. It came with the J321 tube. I agree that it is a well-made device. The FS5000 can be upgraded with Radpro open-source firmware (as can the Fnirsi GC-01) and is then compatible with GeigerLog v1.5 PC software for logging, data transfer and analysis.
The FNIRSI uses an ARM Cortex M3 MCU. However, and also even better, the Bosean FS-5000 uses an ARM Cortex M4 MCU. Here are some specs I found about the two, if you're interested . . . ARM Cortex M3: Program memory size: 64 kB Data bus width: 32 bit ADC resolution: 12 bit Max clock frequency: 72 MHz Number of I/Os: 64 Data RAM size 20 kB Min. supply voltage: 2 V Max. supply voltage: 3.6 V Min. operating temperature: - 40 °C Max. operating temperature: + 85 °C Data RAM type: SRAM Interface type: CAN, I2C, SPI, USART, USB Number of ADC channels: 16 Number of timers/counters: 3 Program memory type: Flash Product: MCUs Moisture sensitive: Yes ARM Cortex M4: Program memory size: 256 kB Data bus width: 32 bit ADC resolution: 12 bit Max clock frequency: 80 MHz Number of I/Os: 52 Data RAM size 64 kB Min. supply voltage: 1.71 V Max. supply voltage: 3.6 V Min. operating temperature: - 40 °C Max. operating temperature: + 85 °C DAC resolution: 12 bit Data RAM type: SRAM Interface type: CAN, I2C, LPUART, SAI, SPI, USART Number of ADC channels: 16 Number of timers/counters: 11 Program memory type: Flash Watchdog timers: Watchdog timer, windowed Product: MCU+FPUs Moisture sensitive: Yes
I bought the branded FNIRSI GC-01 back in 2022 and luckily it has the J321 tube and it works perfectly in line with with my old USA cold war CDV-777. when using the check source they both match to my suprise.
Very interesting review with positive suggestions - I can now confirm mine has the J321 tube so hopefully is as good as it can be. Their products are certainly well designed by and large but have some issues.
I do agree about their products being good value for money, but this product is the first time they created a radiation detector, I suspect that learning curve was steeper than they expected.
In relation to suggested improvements I would add that it would be nice if the user was able to record number of counts over a predetermined period. It could be as simple as a fixed minute. Since there is a microcontroller this should not be a difficult thing to design in.
4:24 the battery inside is just a standard 3.7v lithium cell, so really any lithium cell you can fit in there should work just fine to improve its capacity
The UI and feature set suggest to me that it's trying to be more like a gamma dosimeter than a general-purpose counter. G-M tubes that have a bit of metal shielding to keep out betas and low energy photons ("energy compensation") have energy response curves such that you can estimate gamma dose rate (within a couple tens of percent) from the count rate - IF properly calibrated. However, there's a big problem in that this thing doesn't seem to have a way to recalibrate it in the settings menu. So better hope whatever conversion factors it comes programmed with are accurate I guess. The marketing absolutely bills it as a general purpose device suitable also for x-rays and betas though. No idea why since it seems halfway usable as a dosimeter but doesn't have any of the features you'd want in a general-purpose counter. Maybe there are liability issues if someone relies on it for safety and it fails?
Hi, thanks for the comment. Please take a look at my latest video on this device, the firmware upgrade. Calibration factors are fully adjustable in that 3rd party firmware. There are also factors such as dead-time compensation.
I have a problem. There is no resistor in my model. I have change the tube and add capicitor. Now it worka better but Im not sure if voltage on tube is right.
@@sietra Hi! It was too late when i found this great review.... mine came with a shorter metal tube and no resistor... i measured 200v dc on the tube. Wich capacitor did you add (the one to make the sound or another)? I guess J321 wont work anymore without other changes... Thank you!
@@project-326 Hi! Great video! I'm going to do the sound mod... already have the capacitor. Any chance you would make a video to save the even crapier version of the tube? Measure 200v on the even smaller tube. They must have changed the multiplier circuit. Do you have a hi-res photo of this section of yours? Thank you anyway!!!
The Bosean FS-5000 suddenly has dropped in price from 70~90 to around 55,- and i can confirm it has the J321 tube and data export via USB and ticker. i thank that is also a very interesting GMcounter
I have that very device in my hand right now, it is an excellent device and I will be getting that video uploaded as soon as I get though the current backlog.
Thank you for this review, very helpful. I ordered one of these geiger counters, and mine has a HH614 tube in it. I'm not sure how that compares to the J321, but like the J614, it's much smaller and also has a metal cathode.
unfortunately, that one seems to be about the worst variant they have put into this product. Do you have any test sources or anything else to compare with? I strongly suspect that your sensitivity level will be very low.
I have one that came with the J321 GMT. It still has the resister that you removed. Would it work better if I removed it? Any suggestions would be greatly appreciated. Thanks
If it ain't broke, don't fix it. The anode resistor should be matched with the tube, when they changed the tube, they changed the resistor. Some unis that came with the J321 used a 10M resistor, others can without.
thank you for your review. Just bought a GC-01 on Amazon in October 2024. Mine has a J613 tube. According to your review, unless you upgrade to a J321, you would give the product a zero rating because it does not detect beta particles? according to the description on Amazon the GC-01 should detect beta particles.
Yep, that's what they say on Amazon, but not sure the beta particles themselves have figured out to get through the steel cathode, maybe if they read a bit more of the market BS for this product they can figure it out... The gamma sensitivity of the J613 tube is also terrible, hence the zero rating. Hope that helps!
I am back to this video after a month or so , and I can see you doubled your number of subs, great work mate and keep good work, to be honest came just to see some information you already provided in this video as no others did and I am not expert in this part of electronic. So this video is very useful for me, and going to review some other product of same type , so to see how good is one I got. Only bad thing so far is I don't have any of testing source of radiation to test my detector. Will try to test something soon with X-ray scanners. And again when editing this comment like 12 hours later, you got 4 more subs. It looks too me u going to grow fast now. Gratz
thanks mate! Have a look on the mining data base here to find something locally! www.mindat.org/ if that fails, just try ebay for some fun sources.... Personally I find that sources that are hard to come by are the ones I love the best...
i improved mine by flashing radpro onto it. the preinstalled firmware is garbage, and radpro is not :) also radpro has a setting for particle clicks, which is enabled by default. it also adds logging via the usb interface and a good averaging algorithm.
Wow what a great review ! I'm speachless ! The firmware upgrade is just a amazing idea ! So, that's what I wanted to try. I open the counter and I wasn't surprise to find the J613 but the PCB is just not the same and I tried do many times to upgrade but it just doesn't work at all ! I realy want to do but I think I can just sit on it because I have the feeling that all the new Fnirsi Counter GC-01 PCB have been replaced and connot be upgraded. What did I'm suposed to do ?
Hi, 1) LOVED the review and the direct statement whether it is a POS or not 😂thanks for keeping it real bro.😁👍👍👍 2) Do you sell these units after modding them or can you as we are a Bodyguard agency in Australia and have been advised to purchase a quality one...and so far you are the only one we have come across that make sense.. Any help is greetfully appreciated! 👍 Cheers
Personally, I would buy a better counter for a professional application. If you take a look at this channel, there is a video review of the Bosean FS5000, which is a far better device... ruclips.net/video/Nbz_Nbqgehc/видео.html
It was read on Reddit that there is probably a bug in the FNIRSI brand's firmware that occurs when the dose time exceeds 99 hours. After that, the display was no longer updated and the device can only be operated “blindly”. Can you please test whether this is the case?
I'll keep the dose meter running and let you know if that crops up. It does sound like a very simple bug to fix, so I doubt if that bug lasted very long at all.
@@project-326 Okay, I'm very excited. The error manifested itself in such a way that when switching on the logo still appeared and then a lot of ASCII characters quickly ran through in the bottom line of the display. I already had such a faulty device in my hand, but at the time I didn't know the cause or the solution. The owner had simply left it on because he wanted to test the battery life. In the next comment I will post two links that have to do with the problem, please check whether they are marked as spam.
Thank you! In my case there was J321 tube but also the resistor marked 5105. edit: And in the case someone, like me, will have problem with FNIRSI GC-01, the right hole is indeed for reset button (just imagine how hard that was to write in the manual).
Thank you for your video, i decided to buy a 20 usd second hand fnirsi counter and i will upgrade it as i found the j613 small tube. I understand i do not need to remove the resistor. Changing the tube with j321 is possible but needs new clips right?May i use a hobby solder ? what about tube purchased on aliexpress?
Hey there, I use this Geiger counter around the house. When I tried it on a smoke detector, it went to 5 sieverts but a couple days later when I constantly tried it again, it only went to 1.96. I tried things like: letting it get used to natural radiation levels or resetting the cumulative but still nothing. I know about radiation but this confused me! Please give me advice!
Thanks for the comment, hope I can help in some small way... First of all, I really hope you mean 5 uSv/h, otherwise you have seen a fatal dose. The issue with close up measurements of things like Am-241 based smoke detectors is that it is basically a point source of weak gamma rays and this means that the exact way you hold the detector is going to make a big difference. Also be aware, the tube fitted in you device might be the cheap one that has a solid metal cathode and so the 'geometry' of you measurement can become even more critical. Hope that helps?
@@project-326 Thanks so much man! This helps so much. I can see how this Geiger counter could be problematic in an actual dangerous situation. I'm quite young and I'm really interested in radiation, is there anything in a house that could make my Geiger counter go off?
@@project-326 Also i have one more question if you dont mind, so ive had the fnirsi gc-01 for about a week now and i just wanted to ask is the radpro software or the stock one better? you've had this device for a while and you would probably know, thanks
Hi. I love your material. I need a current recommendation for a geiger counter in order to test a vehicle from Fukushima Prefecture that is currently in my driveway. I appreciate any input you have.
For contamination measurement, you will probably need something more sensitive than a Geiger counter. Perhaps take a look at the Radiacode review on my channel, this is better suited for your application.
Perhaps use a telephone type coiled cable. I also thought about this a while ago, 3D printing a custom enclosure for the tube. Instead of using spring clips to hold the new tube 'wand' to the side of the device, I was thinking about using a magnetically secured wand and 3D printing the instrument-end magnet holder with a shape that matches the wand shape itself to ensure a better grip. BTW, I have found that a cheap selfie-stick grips the device pretty well so this is also a nice option for ground surveys without the need to visit a orthopedic doctor afterwards. I just did this to help with surveying the tailings heap of an old uranium mine - I'm currently working on that particular video...
Wow! What a wonderful review. The FNIRSI brand makes all kinds of test equipment. Such as the: $165 FNIRSI DPOX180H 2 Channels Digital Phosphor 180Mhz Oscilloscope. However , after watching this video I am leery of this brand. If they dumb down their products I will pass. 😎 Thank you.
I am actually wondering if this was done due to issues with the availability of the J321 tube. I bought my replacement J321tube for about $12 on Taobao, but the other locally made types are about half that cost on the same platform. Many GM tubes are made in Russia, so this might be impacted by the war in Ukraine. I say *might*, I don't have any hard data.
2:18 Always buy from the official store. Even then you get things with no branding, e.g. my RD Tech TC66 meter where there's no company name on the meter itself.
Typically, here in China, the unbranded version is made by the same factory as the branded one. This happens because the brand doesn't want to pay for the tooling and certifications and pushes those costs onto the factory but in return, the factory can then sell the product but not with their original brand customers' marque.
I could not resist to buy another of these, just to confirm the change of tube. And as you are writing, the replacement tube makes this unit a piece for the junk-yard! So folks: until Fnirsi change back to a usable tube - Dont buy! It appears that its a third, even shittier tube, HH614 in the one I bougt
hey man, thanks for the video, wish i saw it sooner. I bought one and it doesnt work at all. Has the small tube in it but im lucky as the resistor is not there and the tube connectors for the larger tube are on the board as well. Im in Australia and was wondering if the j321 on ebay are legitimate? thanks
If you are going to buy tubes, best to buy new ones. Take a look at the Manutek4000 channel for the issues that can happen with eBay tubes. He bought J321's on eBay and they were all useless.
@@RWE870 It is kind of hard to measure that. Normal DMMs have an input impedance of 10M, which is in the same order of magnitude as the anode resistance. I don't remember exactly, but measuring before the anode resistor gave about 380 to 400V
I have 2 of this devices the first has the brand name fnirsi and has a j321 tube the second is blue colour the brand is joy-it from simac electronics in germany and has M4011 tube made in 2023 what is your opinion about this tube??? thanks in advance!!
Did you add the 100nF cap in series with resistor or only the capacitor ? I tried first 2.2K and the sound was weak, then I replaced it with 100n cap. and the sound became even weaker, now I'm running with 2K, but the click sound is still very weak. P.S. I ordered mine from aliexpress and it is with M4011 tube, google said it's the same spec. as J321.
The sound isn't the loudest, but there is a better solution. In this video I used only the cap. If you look on this channel you will find a video about a FW upgrade, which give very decent volume level clicks... You are correct, there is almost no difference between the M4011 and the J321. I hope that helps!
I have 2 of this the first is with name on it fnirsi and i opened it and has a j321 geiger muller tube the second is blue colour and brand is joy-it RAD01 by simac electronics it is sold in germany in conrad store and in other parts of europe like greece i opened it also and i was amazed it has a m4011 geiger muller tube made in 2023 what is your opinion about this tube in this device?
@@project-326 yes but no name have the crappy j613 tube!! The fnirsi brand has the j321 tube!! do you know information about the M4011 tube?? I found on google it is quite good
I heard someone also fitted a small solar panel at the back of the case. Neat but, given the weak current it gives, it'll take...quite a while...given my experiences with a panel that...small... It's pronounced fuh-NEAR-SEE, but FixCo sounds better.
btw Does anyone know what battery pack connector that is? I want to replace it with an even larger one. Rad Pro firmware kinda cut down the battery life.
the changes that have been made to this product have occurred in the last couple of months, so you probably have the good version! It a shame that this product has now been hobbled in such an awful way.
@@andreafavero4250 I know that horrid feeling. I only bought my RC102 a couple of months ago, and just before they reduced the price by $100. I seem to be particularly unlucky, a similar thing happened with the KC761 too. Fuckty-fuck.
@@andreafavero4250 The Radiacode 103 has just a bit better resolution. 8.2% ±0.4% FWHM (Full Width at Half Maximum) versus the 102 with 9.5% ±0.4% FWHM. You’ll need to be doing some serious Gamma spectrometry to notice the difference.
@@project-326it's alright my man, I actually bought two for the black friday event and I have literally zero regrets. It's not like the 103 makes mine less godd at what they do and yes, it's annoying that we didnt know earlier it was going to come out but I have no hard feelings agains the company, also because a product so well designed that can perform gamma spectroscopy shouldnt cost this little. And also I want to thank you thorough review that made me go for it. I absolutely love mine and I will give the second one to a friend of mine because he travels a lot and it will be interesting to see the radiation maps :)
I've just opened the device I bought from Amazon UK, and it's even worse with an even smaller tube inside. The tube inside is unlabelled and has double sided tape and foam holding it in place. Doesn't even have the mounting for a real GM Tube. I can show you the photos.
Yes, I have seen from the comments, the company has found an even cheaper GM tube, it looks like a Christmas tree light... The pad for the J321 should still be present on the PCB and if you get a replacement J321 tube, it is supplied with the clips that solder into the board.
well now i feel so lucky taht my 2 fnirsi gc-01 order six mounth apart from each other have both the j321!!! thnak you for that review ! do you have a video about what thrshold value i should put in there?
I assume that you mean the alarm threshold， right？ I normally have mine set to 1uSv/h. If I'm in an area that has dose rates higher than that, I probably want to find out why...
@@offroadbaddude1 Actually, I'm British, my family is from a typical English south coast seaside town. Not sure if I will ever go back there though. I have lived here in SZ for nearly 2 decades and during that time the UK has had more than a few collective 'brain farts' that has set the nation back by about 2 decades. So when I visit, it's like the land that time forgot...
@@project-326 well this explain that!! brain fart are common in canada too ... people's brain freeze in the winter so every spring they repeat the same mistake ... i rather stay close to my wood stove !!! maybe global warming is not a bad thing after all 😂
there must be 2 versions randomly sold. one with the original tube and one with the smaller tube. i bought it a week ago from fixco and it has the big tube.
I think it has a lot to do with which vendors are holding stock of the older devices. Typically, the guys with the older stock will be motivated to sell quickly by lowering their prices. Money tied up in stock for these small 'nobody brands' is pretty tough to deal with, and frankly if they are just drop-shippers, they won't know which model is which, which model has a good tube and which has a $hitty one (they probably didn't even see, or test, a single sample of the product before buying several thousand of them, they typically just look at Amazon sales numbers for other brands selling the same OEM product).
If so, one element that was unclear from your upgrade video was what to do after removing the extra loading resistor. Leave the space empty? Solder a different resistor? Connect the terminals with a plain piece of wire? Sorry, I have only a basic theoretical understanding of these things, but certainly not a practical one! Also, are there any precautions to take when taking the meter apart, so as not to break anything? (Edit - no, there are just 4 screws, which are retained in the housing, so you don't lose them. The battery is on the back panel and connected with a couple of wires, but there is lots of room.) Update, I opened mine up, and it was an easy process. I discovered I have an even smaller J613 tube (the new board is designed for it , as there is an outline for it). There are connection holes for a larger tube, I think, but will they be connected on the under side of the board? And will the 321 come with a pair of holders that fit? Also, it appears the loading resistor you removed in your previous video is no longer present. I wish I could post a photo.
I have seen an updated PCB design that used the even more crappy J613 tube, the race to zero, on this product design continues unabated. In the end, I used a 20M loading resistor on my device.
isnt .2 to .3 microsieverts on the high side for background radiation? i am thinking of upgrading my own tubes because mine was also originally reading an average of .1 and i thought it might also be underreading levels but everything ive read says .1 should be around the average for bg radiation
Indeed it is, after making this video, I discovered that the loading resistor should not be removed but adjusted to match the PSU (the voltage is very erratic between devices). With a 10M loading resistor, the readings became a lot more reasonable. Here in Shenzhen, I normally see about 0.18 nSv/h when averaged over a reasonable period of time. When I made this video, it was summer in this tropical region and the humidity was over 85%, but when the winter came, and with it the lower humidity, I noticed that the tube voltage was getting too high...
Actually, somebody else already did it. I am making a video about this firmware upgrade and the video should be finished in a day or so. Make sure you are subscribed to be notified when that is released.
The LED output signal, sorry I didn't show that bit, with hindsight that was a little tardy of me. If you pause at 9:55, the other end is connected to R33, at the side that is shown downward in this photo. I will add this to the description, thanks for letting me know!
Because the capacitor results in a positive pulse at the beginning of the LED pulse signal, it will energies the peizo sounder via the transistor. If the alarm is active, the negative pulse at the end of the LED pulse, will cause the alarm signal to be briefly interrupted and this allows the particle sounds to still be heard, albeit, as interruptions to the alarm sound.
sorry for the late reply. That does depend upon if you feel that you can do the mod, I'm the ham-fisted type so I have to go really carefully with the soldering iron...
ok, thanks! I would need clear instructions on how to do it... I have read that it is also necessary to recalibrate the high voltage that supply the tube and bring it to the manufacturer's recommended rating...
interesting… I bought mine labeled as Fnirsi a year ago and it came with the J321 tube. However have the resistor that you removed soldered to the PCB but it doesn‘t look reworked. Does anyone else have the J321 with the resistor in place?
My has some weird even cheaper version of that J613 shit tube. Weird because it is much shorter. It should be 85mm instead it is 51mm barely. Less surface area i guess even less sensitive... However it doesnt have thar rezistor soldered. Its empty. Maybe it is alredy modified power supply? Do not know if i can even use aftermarket J321 tube anymore. I can try to measure voltage however my multimeter impedance would load power supply therefore i will got wrong measurement. It would take oscilloscope with much higher imput impedance wich i do not have.
For what it's worth, I just got one of these (box dated 2024-11-7) from the FNIRSI brand, and it looks like they reverted to the J321 tube, and have made a firmware upgrade to version 1.8 . . . (I have a pic, but Screwed Toobe won't let me post it . . . )
Hi thanks for doing this video. I had ordered one of these on Amazon before seeing your review. On recieving the item i opened it up and it appears to have a J321 tube so at least thats something. Im not sure if its a goid idea for me to go at it with a sokdering iron as ive never really used one. Something i would like to know is more about the setting in the device. I bought it more out of curiosity than actually needing one but i have no idea about the readings. Also is there a more in depth video of fitting the upgrade to gain the audio clicks? Im looking at is as a bit of a project and a learning tool. Can you recommend a type of sample to test it with too please?
Hi David, Thank you for the comments and questions. The first thing to say is "if it ain't broke, don't fix it". As for other videos, there are a couple more on my channel, but look around on the channel page (I don't have many videos), there is one for a firmware upgrade, that might be of use to you. You remind me of myself "I bought one out of curiosity" and now "where can I find test samples?". I think that many of the folk who are regular viewers found themselves with a new hobby through exactly this process! :-) E-bay is a good source of test samples. Be careful buying uranium glass, much of it is fake but things like ionization chambers from smoke detectors and alike are useful sources.
That's a really difficult one to answer, it really depends upon what the application is. With low-cost devices, there is always something missing from the spec...
I got mine and i can confirm it uses even more cheap and shit tube that already discounted version J613. It doesn't even has a name. I found it on Ebay as simply "HG Geiger Counter Tube". Looks simillar to J613 but is is much shorter instead 85mm inlength its around 51mm. Even less surface area = even less sensitivity. However it doesnt have that loading resistor on PCB. Maybe it is alredy modified power supply? Do not know if i can even use aftermarket J321 tube anymore.
Did you figure it out? I bought one too and it has a tube 47 mm in length, again with no markings. Mine doesn't have a loading resistor either. It seems that they changed the board design: the tube is properly mounted with it's leads going through the board, around the halfway point. The PCB markings for the J321 tube are still there though.
@@oskarantola2616 I since bought another radiometer. Pripyat RKS 20.03 Polaron Dosimeter with two tubes SBM-20 side by side. Much older and higher price but also much more sensitive and quite respected among the community of users. Still planning the upgrade the FNIRSI one even might be able to measure the voltage with hi impedance oscilloscope in work. Will see how it goes. Will report here if successful. PS by the description you have the same tube as me. Was your in some way secured to PCB other than just by wires? Mine was on wires on one end and flipping in the breeze on the other end of the tube. I put some double side tape under it to stop it from vibrating the wires. They would eventually break I suspect.
@@josifvissarionovich5320 Looking forward to it, hope you're successful! Mine already has some double-sided tape in between the tube and the PCB from the factory. Does your PCB have markings for the smaller tube, too? Also, I measured that the high voltage does still come to the J321 fitting contacts so perhaps this isn't a lost cause. The little tube seems to fit the description of a HH614 GM tube, though no markings. The recommended operating voltage for the HH614 is 420 V, which gives me hope that the power supply might have enough voltage for the J321.
@@oskarantola2616 So is mine, bought 2024, Feb. 1st on amazon: About 50mm short tube without any markings. No fuse type holders, directly soldered to the PCB. No loading resistor. I measured about 320 volts at the tube with a DVM. Today I installed a J321 tube without any changes at the HV stage. The GC-01 has about 5 to 8 times better sensitivity. With the short tube readings were about 2-3 times less than a BR-6, no it is about 5 times more than BR-6. But on normal radiation a reading of ~0.50uSv/h is much too high (BR-6: 0.10 uSV/h). @studio326- thank you for that very good video!!! @wolf1403
@@wolfganglehmann2717 Does this mean that the meter isn't calibrated correctly for the J321 anymore? Could the problem be fixed by installing an older firmware?
If I open it and it comes with the one it was originally designed to have, does that mean Its alright? Or do u think stock from them is still gonna be horrid
That is catch 22, the date code is usually recorded on the PCB. That said, this company has chopped and changed between tubes, so the only way to he sure is to open it up and look at the tube. I guess the logic could be as follows: If it is a J321 tube, then there is no need to send it back. If it isn't, you could always update it? ;-)
@@project-326 Thanks for the reply! I did decided to open it up, and it has the J321 tube, just like the pic in your clip above. Also, there was no center screw, just the four corners. Maybe this is a newer update?! I don't have any standard sources to check, but it did agree with the readings taken via a radiation safety Geiger Mueller counter.
I bought my product named GC-01, on 03.08.2024, it even has FNIRSI GC-01 printed near LCD, however it uses vastly different board. it doesn't have supporting pins fot the tube at voltage outputs, it uses some nameless tube (maybe J613). Is there any possibility of perhaps mailing You the photos, so You can judge, if it's possible to mount the J321 tube on this board ?
Just got mine few days ago, i do have the J321 tube but the resistor you mentioned is also there, should i attempt to remove this? The only other rework i see on my pbc is they added a nice battery holder for the cr1220
if it has the correct tube, then don't change anything, the resistor has been matched to the tube. I have seen several different values for the load resistor in the comments, the one on mine was originally very low and thus pulling the tube voltage too low for J321 to correctly operate. Do you get normal readings for background, etc?
@@PlagueDoctorX312 It will be for matching to the tube type. This is just to make sure that the tube is operating correctly (Geiger mode). The calibration, ie counts/min to uSv/h will be in the firmware.
UPDATE - Don't remove the loading resistor (R38) - it isn't necessary...
Consumers everywhere salute you!
This man must be protected.
Even when the tube is changed?
@@blackfox_357chief4 When I made this video, it was summer here in the tropical region of China and the humidity was consistently over 85%, once winder arrived I found that without the loading resistor, the PSU voltage peaked pretty high and caused some ionization in the tube.
It should also be noted that as part of an crowd-science experiment I am currently running, it seems that there is a lot of manufacturing variability in the PSU voltage of the GC-01.
@@project-326 So you can speak chinese too? Amazing!
I've watched a handful of your videos now, and want to thank you for the work that you put into them. In this one, you researched the company and also the white-box situation with this product. You did a thorough review and identified not only its shortcomings, but why. And as a bonus, how you worked around them. Your work is really over the top. And the post-production graphics and editing are really nice. Again, thank you.
This really helped too! Good luck with the new camera!
thanks dude, that make a big difference - I hope that you got something useful from the video.
I bought this p.o.s. and I dont know why I didn't look for video reviews first. Well, after being very disappointed by my purchase, I found this video, and it's making me feel so much better. I was worried that I was doing something wrong, but now all my suspicions are confirmed, and I've gotten to laugh a bit too! Lovely video!
Watched your video after I purchased one. Mine has the actual name on it. When I opened it it had the correct tube and no resistor. I think there may be several manufacturers using same case. But different internals. Thanks for the video.
I bought a device with a starting data of 2022. The seller contacted FNIRSI and said that his product was one of the newly produced versions. When I received the product, I opened it and looked inside, the battery had a production date of 24/07 and there was a Geiger Müller tube, M4011 tube, which is the same as the J321 but given a different name. The tests I conducted gave the same values as the J321. I think the manufacturer continues to produce the J321 "M4011" for FNIRSI.
Actually the factory owns the FNIRSI brand, so they have complete control over what tubes go into their branded products and what goes into the white label devices they sell separately.
This was very helpful and insightful. I saw this on Amazon and figured “what a great price”, but with all things cheap, you get what you pay for. I was wanting to know if this was worth the $70 on Amazon and thanks to you, you saved me from spending my hard earned money. I’m sure there is better out there that I’m not afraid to throw extra money into it, provided that it is a good product. Much appreciated
[Oct. 2024] I just bough mine and was indeed full of questions. After looking this video I opened it and yes, it is now "upgraded" with a shitty tube and cheap battery... thanks for the review
sorry to hear that. For some companies, its about cost and not value...
Thanks for making such a great review with insides. Great work!
Congratulations on the excellent videos! After changing the GM tube the measured level (background too) flew into the sky. Fortunately, your new video about the firmware upgrade helped to fix the error. With your help, this GM counter has been a good, cheap instrument. THX!
Great review, i am strugling with the low sensitiviti and indeed i have the small tube. ordered the better tube now. Thanks!
btw love the James May voice over.
be sure to give me a mention on your wonderful channel!
:-)
@@project-326 Yes ofcource! i realy like your work
@@TonyAlbus I also like yours - your business model is also particularly inspired. If I ever decide to make this channel pay for itself, then your chosen model is one that I would consider...
@@project-326 Thank you! ...its still hobby, but i like it a lot and that maybe shows... maybe it will be a business someday. thanks for the compliment.
I upgraded the crappy POS tube I had, to a J321, installed the RadPro software and upgraded the 1100mah battery to a 3500mah battery. *update* We are over 40hrs run time and counting now.
Ps: the clips you need to solder on for the J321 tube are heavy duty fuse clips.
Hi is it simple to change the tube? i have a j613 and i want to change with the j321. The pcb will accept this upgrade? may i use a hobby solder ?
I ordered mine in december 2022 from TomTop and paid 39,59€ ( arround $43) after seeing the review done by IMSAI Guy.
I didn't know there were (or are) 2 types of tubes for this meter. I just checked, and mine has the J321 tube. Thanks for sharing this information. Grtz
Such a good review , while watching it had feeling it comes from great and big youtuber, and now when I noticed 427 subs only , wondering why u don't have more. Where is issue.
so you mean that I am not a "great RUclipsr" then? 🤣🤣🤣
Not sure why the YT algo doesn't like me, probably because I routinely tell it to go and get f**cked...
Hi, I bought my FNIRSI GC-01 ne week ago via Amazon.
I opend it up right away, and found a J321 tube in it.
The date of production on the box is 2023-07-11
I gues I was lucky 😊
I totally like your suggestions to optimise this product.
Thanks for this amaising reviev 👌🥰
That's good news! I guess it just goes to show that there is a lot of stock in various parts of the delivery supply chain...
Have the j321 tube came in a box dated may 2023
The boxes have dates of manufacture on the side
Be easy to ask a seller when it was made
It seems these earlier ones are 👍
I was really upset with mine. It was advertised with a big tube and the one i got was tiny. It couldn’t detect americium or soft xrays. I was irritated considerably
@@Wtfinc Same situation. Very disappointing.
Same here only 4 screws.
My original J321 FNRISI GC-01 has a 516 SMD resistor at R38. I bought an unbranded GC-01which had a J613 tube and no resistor at R38. Replacing the 613 with a 321 did improve but still seems a bit low compared to the original. I'll try adding a 516 SMD resistor at R38 and see if it improves.
I'm making a new video about the UV sensitivity of GM tubes (the second part) and a key aspect of the video is about the production tolerances of the power supplies used in products like this, so keep an eye out for that, it might help to set the loading resistor.
I am going to be asking viewers that have detectors like this, to help with participating in some experiments - a sort of crowd sourced experiment. I am hoping that if enough people get involved, we can actually all learn something new. I hope you will be able to join in the experiment?
You are a hero!! I have been educated, more importantly i have laughed like a little girl, thank you 🙏🏻
Awesome dedication to relevant and accurate information. Cheers.
Nice upgrade - thumbs UP!
Thanks 👍
many have said it already but it's not enough, your review is great if not the best
I appreciate that!
13:13
A warm fuzzy feeling? Huh... I would go to the hospital just in case. 😂
warm, like a radium bath....
Re: the two tube "options". I received one of these this week from AliExpress and it has the (better) J321 tube, so maybe they did watch your video and took note. Secondly the tube's sensitivity to beta is limited by the plastic and rubber case. I do a demo ofcollecting radon decay products from the air in a house. When I presented the sample to the tube with the case open I got a much higher reading than when the tube was boxed up in the case. If this concerns any reader (especially since the radon demo is quite a polular thing to do) it would be possible to cut a long hole down the side of the box , or of course design a whole new box for it.
Thanks for you're investigation! You helped make my educated decision .
Thank you so much for this video, returning mine now!
You could always have some fun and 'upgrade' it...
😉
I have this FNIRSI GC-01, purchased around August/2023 and I can confirm they changed the tube for an even WORSE Version than the J631, the new one is half the size around 50mm long only.
After watching your video, I ordered a J321 and will make this mod. thank you very much for the video!
Edit: I've just found the model installed it's a J613.
I have the same. Were you able to replace the tube with the original J321? If so, any issues?
Thank you for your video - i just started getting into Geiger Counters- bough a the cheap FNSRI GC-01 as a starter unit to explore Geiger world.
Wow excellent review and upgrade , I have this unit and had no idea as to its inadequacies. I just took mine apart and confirmed I still have the J321 tube in mine. I must have old stock. The other caveat is there is a fastening screw underneath the small black label on the back that would’ve been nice if you had shown that has to be removed it’s hidden under the plastic black label peel it off and there’s a screw under there to remove. I know you know that but watching the video I don’t think anybody else knew that but thanks again for your great analysis of this product. Cheers.😊
I really appreciate the feedback, thank you!
Perhaps the mechanical design has been updated in the version that I have, but I didn't need to remove that label to get the unit apart, as you can see in the tear down, there is no hole in the middle of the PCB to accommodate a 5th screw post. Just the 4 corner screws were removed and mine came apart. I looked at some other YT reviews with tear-down's and this was also the same (if you find any different, please post a link here).
I have been asked to do a quick video to clarify the details of how I added the particle sounds, so I will be sure to include a part about this aspect, so you can see this on my version of the device.
I have also had an extensive email exchange with the FNIRSI and their B2B commercial sales team confirmed that the factory that makes the branded products also manufacturers the unbranded ones (which is usually the case here in China) and FNIRSI even helps with this sales process and I assume they even earn a commissions as the white label versions are sold through their B2B team.
@@project-326 weird mine has the hidden screw under the label, it’s a branded FNIRSI too not a white label product . Anyway thanks
Again 👍
@@ralger I'm pretty confident that if there is a design change, it will have efected all of the versions. When did you get yours? FNIRSI confirmed that the change to the new tube was pretty recent. The sales guy said they changed over to the new GM tube（几个月前）which translates to a number of months ago (between 1 and 4, there is a different expression for numbers between 5 and 10).
@@ralger you are most welcome Sir!
@@ralger I just released an update for those wanting more info about how to add the particle clicks and I made a special effort to show the absence of the additional screw on my unit. Please take a look and let me know your feedback!
It would be really strange if the tooling for this as changed, that is a very expensive change to make. When they changed to the new $hitty GM tube, they didn't even bother to update the PCB but just did some hand mods.
Updating the PCB is pretty cheap in comparison!
I finally managed to do it! I successfully reviewed a product and didn't mention the Gamma Scout (PoS) once. What is a PoS? Its a Piece of $hit, of course...
Next time, I might have a few more words to share regarding that amazing product!
🤣🤣🤣
I bought the device even after seeing this video because I don't mind tinkering. It's absolute trash. Even sitting on top of my ENTIRE BOX of spicy rocks, it only measured 1.03 uSv/h. My other cheap (and more expensive counters) scream. Lol
Do you think changing out the tube to the J321 impacts the factory calibration?
@@AngryGopher612 Wow, that is true dedication to the art of "'tinkering"!
There is no way to know for certain, but it looks like they just changed the tube and the firmware is the same as the old version.
After I added the J321 to my device, the levels were a lot more normal (a little on the high side in some cases).
They must have changed the software also, to reflect the lower cps conversion into uSv/h. I have now changed my tube to the original J321 and it works, giving around 2.5 higher cps. But the uSv value is of course way to high. Of course the uSv is not accurate for anything, even on the original model, as its only calibrated for CS137, and even that, giving some errors due to some sensitivity even to hard Betas. But now its more the twice bakground. @@project-326
Hi, thank you for your review and these valuable information and insight! I bought this device about a year ago. It has the J321 tube in it I remember it because I was once in a hurry and dropped it and it stopped measuring. When I opened it, mine had no glue at the place of the tube so the tube moved after it hit the ground and lost contact. I moved the tube back in place and it works again. However Its a shame they have changed the manufacturing process, its misleading the customers.
Yup, its a kind of "bait and switch" operation...
I bought one. It had a cracked tube. They moved to a different tube design (one with wires and soldered leads like you mentioned in the video) that is just taped down at a weird angle so it fits inside the housing. Since mine had a cracked it worked even worse than the one you tested, as in not at all. I think you're 100% correct in your analysis.
I has been great to see all the various differences that people have found and commented about...
Thanks for the feedback!
I sold my Pudibei NR1050 and bought the Bosean FS5000. It came with the J321 tube. I agree that it is a well-made device. The FS5000 can be upgraded with Radpro open-source firmware (as can the Fnirsi GC-01) and is then compatible with GeigerLog v1.5 PC software for logging, data transfer and analysis.
The FNIRSI uses an ARM Cortex M3 MCU. However, and also even better, the Bosean FS-5000 uses an ARM Cortex M4 MCU. Here are some specs I found about the two, if you're interested . . .
ARM Cortex M3:
Program memory size: 64 kB
Data bus width: 32 bit
ADC resolution: 12 bit
Max clock frequency: 72 MHz
Number of I/Os: 64
Data RAM size 20 kB
Min. supply voltage: 2 V
Max. supply voltage: 3.6 V
Min. operating temperature: - 40 °C
Max. operating temperature: + 85 °C
Data RAM type: SRAM
Interface type: CAN, I2C, SPI, USART, USB
Number of ADC channels: 16
Number of timers/counters: 3
Program memory type: Flash
Product: MCUs
Moisture sensitive: Yes
ARM Cortex M4:
Program memory size: 256 kB
Data bus width: 32 bit
ADC resolution: 12 bit
Max clock frequency: 80 MHz
Number of I/Os: 52
Data RAM size 64 kB
Min. supply voltage: 1.71 V
Max. supply voltage: 3.6 V
Min. operating temperature: - 40 °C
Max. operating temperature: + 85 °C
DAC resolution: 12 bit
Data RAM type: SRAM
Interface type: CAN, I2C, LPUART, SAI, SPI, USART
Number of ADC channels: 16
Number of timers/counters: 11
Program memory type: Flash
Watchdog timers: Watchdog timer, windowed
Product: MCU+FPUs
Moisture sensitive: Yes
I bought the branded FNIRSI GC-01 back in 2022 and luckily it has the J321 tube and it works perfectly in line with with my old USA cold war CDV-777. when using the check source they both match to my suprise.
Very interesting review with positive suggestions - I can now confirm mine has the J321 tube so hopefully is as good as it can be. Their products are certainly well designed by and large but have some issues.
I do agree about their products being good value for money, but this product is the first time they created a radiation detector, I suspect that learning curve was steeper than they expected.
In relation to suggested improvements I would add that it would be nice if the user was able to record number of counts over a predetermined period. It could be as simple as a fixed minute. Since there is a microcontroller this should not be a difficult thing to design in.
4:24 the battery inside is just a standard 3.7v lithium cell, so really any lithium cell you can fit in there should work just fine to improve its capacity
I really enjoyed watching this review, regards
inventor KR
I have also really enjoyed watching your channel and seriously recommend it to everyone!
The UI and feature set suggest to me that it's trying to be more like a gamma dosimeter than a general-purpose counter. G-M tubes that have a bit of metal shielding to keep out betas and low energy photons ("energy compensation") have energy response curves such that you can estimate gamma dose rate (within a couple tens of percent) from the count rate - IF properly calibrated. However, there's a big problem in that this thing doesn't seem to have a way to recalibrate it in the settings menu. So better hope whatever conversion factors it comes programmed with are accurate I guess.
The marketing absolutely bills it as a general purpose device suitable also for x-rays and betas though. No idea why since it seems halfway usable as a dosimeter but doesn't have any of the features you'd want in a general-purpose counter. Maybe there are liability issues if someone relies on it for safety and it fails?
Hi, thanks for the comment. Please take a look at my latest video on this device, the firmware upgrade. Calibration factors are fully adjustable in that 3rd party firmware. There are also factors such as dead-time compensation.
@@project-326 oh, thanks and sorry for missing that video!
I have a problem. There is no resistor in my model. I have change the tube and add capicitor. Now it worka better but Im not sure if voltage on tube is right.
I have run without a limiting resistor since I made the change. Are you getting a better sensitivity now?
@@project-326 Yes sensitivity is much better.
@@sietra Hi! It was too late when i found this great review.... mine came with a shorter metal tube and no resistor... i measured 200v dc on the tube. Wich capacitor did you add (the one to make the sound or another)? I guess J321 wont work anymore without other changes... Thank you!
@@project-326 Hi! Great video! I'm going to do the sound mod... already have the capacitor. Any chance you would make a video to save the even crapier version of the tube? Measure 200v on the even smaller tube. They must have changed the multiplier circuit. Do you have a hi-res photo of this section of yours? Thank you anyway!!!
@@K-IQ I think that they just use the loading resistor to change the DC voltage from the multiplier circuit.
The Bosean FS-5000 suddenly has dropped in price from 70~90 to around 55,- and i can confirm it has the J321 tube and data export via USB and ticker.
i thank that is also a very interesting GMcounter
I have that very device in my hand right now, it is an excellent device and I will be getting that video uploaded as soon as I get though the current backlog.
@@project-326 Great! looking forward to your review.! keep up to good work!
Thank you for this review, very helpful.
I ordered one of these geiger counters, and mine has a HH614 tube in it.
I'm not sure how that compares to the J321, but like the J614, it's much smaller and also has a metal cathode.
unfortunately, that one seems to be about the worst variant they have put into this product. Do you have any test sources or anything else to compare with? I strongly suspect that your sensitivity level will be very low.
@@project-326 sadly I don’t have any test sources, nor do I have another Geiger counter to compare background too
Other then the particle clicking mine is branded and when i opened it i found a j321 tube
Anyidea when i start my counter i have a long peeep and the bootscreen hangs. I have the gc01 with the old tube
Sorry, but I don't really know. You could always try upgrading to new firmware, there is a video on this channel about that...
I have one that came with the J321 GMT. It still has the resister that you removed. Would it work better if I removed it? Any suggestions would be greatly appreciated. Thanks
If it ain't broke, don't fix it. The anode resistor should be matched with the tube, when they changed the tube, they changed the resistor. Some unis that came with the J321 used a 10M resistor, others can without.
thank you for your review. Just bought a GC-01 on Amazon in October 2024. Mine has a J613 tube. According to your review, unless you upgrade to a J321, you would give the product a zero rating because it does not detect beta particles? according to the description on Amazon the GC-01 should detect beta particles.
Yep, that's what they say on Amazon, but not sure the beta particles themselves have figured out to get through the steel cathode, maybe if they read a bit more of the market BS for this product they can figure it out...
The gamma sensitivity of the J613 tube is also terrible, hence the zero rating.
Hope that helps!
@@project-326 yea, it helps, thank you. I will return the product.
I am back to this video after a month or so , and I can see you doubled your number of subs, great work mate and keep good work, to be honest came just to see some information you already provided in this video as no others did and I am not expert in this part of electronic. So this video is very useful for me, and going to review some other product of same type , so to see how good is one I got. Only bad thing so far is I don't have any of testing source of radiation to test my detector. Will try to test something soon with X-ray scanners. And again when editing this comment like 12 hours later, you got 4 more subs. It looks too me u going to grow fast now. Gratz
thanks mate! Have a look on the mining data base here to find something locally!
www.mindat.org/
if that fails, just try ebay for some fun sources....
Personally I find that sources that are hard to come by are the ones I love the best...
i improved mine by flashing radpro onto it. the preinstalled firmware is garbage, and radpro is not :) also radpro has a setting for particle clicks, which is enabled by default. it also adds logging via the usb interface and a good averaging algorithm.
1:05 Ahhhh so maybe those crazy company names really have some logic to them and they aren't just feeding the output of a random password generator.
🤣
Wow what a great review ! I'm speachless ! The firmware upgrade is just a amazing idea ! So, that's what I wanted to try. I open the counter and I wasn't surprise to find the J613 but the PCB is just not the same and I tried do many times to upgrade but it just doesn't work at all ! I realy want to do but I think I can just sit on it because I have the feeling that all the new Fnirsi Counter GC-01 PCB have been replaced and connot be upgraded. What did I'm suposed to do ?
Hi,
1) LOVED the review and the direct statement whether it is a POS or not 😂thanks for keeping it real bro.😁👍👍👍
2) Do you sell these units after modding them or can you as we are a Bodyguard agency in Australia and have been advised to purchase a quality one...and so far you are the only one we have come across that make sense..
Any help is greetfully appreciated! 👍
Cheers
Personally, I would buy a better counter for a professional application. If you take a look at this channel, there is a video review of the Bosean FS5000, which is a far better device...
ruclips.net/video/Nbz_Nbqgehc/видео.html
Amazing review. Could you make an in depth video on how to swap the tube for a j321?
It was read on Reddit that there is probably a bug in the FNIRSI brand's firmware that occurs when the dose time exceeds 99 hours. After that, the display was no longer updated and the device can only be operated “blindly”. Can you please test whether this is the case?
I'll keep the dose meter running and let you know if that crops up. It does sound like a very simple bug to fix, so I doubt if that bug lasted very long at all.
@@project-326 Okay, I'm very excited. The error manifested itself in such a way that when switching on the logo still appeared and then a lot of ASCII characters quickly ran through in the bottom line of the display. I already had such a faulty device in my hand, but at the time I didn't know the cause or the solution. The owner had simply left it on because he wanted to test the battery life.
In the next comment I will post two links that have to do with the problem, please check whether they are marked as spam.
😢@@dg0mg
VERY USEFUL !!! THANKS A LOT!
Thank you! In my case there was J321 tube but also the resistor marked 5105.
edit: And in the case someone, like me, will have problem with FNIRSI GC-01, the right hole is indeed for reset button (just imagine how hard that was to write in the manual).
😆 Always be sure to find the right hole when you need a quick reset...
Except there's no button inside!
Díky za info, mám ještě tu původní verrzi s J321.
saves replacing it!, nice.
Thank you for your video, i decided to buy a 20 usd second hand fnirsi counter and i will upgrade it as i found the j613 small tube. I understand i do not need to remove the resistor. Changing the tube with j321 is possible but needs new clips right?May i use a hobby solder ? what about tube purchased on aliexpress?
Hey there, I use this Geiger counter around the house. When I tried it on a smoke detector, it went to 5 sieverts but a couple days later when I constantly tried it again, it only went to 1.96. I tried things like: letting it get used to natural radiation levels or resetting the cumulative but still nothing. I know about radiation but this confused me! Please give me advice!
Thanks for the comment, hope I can help in some small way...
First of all, I really hope you mean 5 uSv/h, otherwise you have seen a fatal dose.
The issue with close up measurements of things like Am-241 based smoke detectors is that it is basically a point source of weak gamma rays and this means that the exact way you hold the detector is going to make a big difference.
Also be aware, the tube fitted in you device might be the cheap one that has a solid metal cathode and so the 'geometry' of you measurement can become even more critical.
Hope that helps?
@@project-326 Thanks so much man! This helps so much. I can see how this Geiger counter could be problematic in an actual dangerous situation. I'm quite young and I'm really interested in radiation, is there anything in a house that could make my Geiger counter go off?
is the m4011 tube a cheap bad one or is it good as the j321
They are almost identical, reasonable tubes for the price.
@@project-326 also what would be a good upgrade tube for this geiger counter
@@project-326 Also i have one more question if you dont mind, so ive had the fnirsi gc-01 for about a week now and i just wanted to ask is the radpro software or the stock one better? you've had this device for a while and you would probably know, thanks
Hi. I love your material. I need a current recommendation for a geiger counter in order to test a vehicle from Fukushima Prefecture that is currently in my driveway. I appreciate any input you have.
For contamination measurement, you will probably need something more sensitive than a Geiger counter.
Perhaps take a look at the Radiacode review on my channel, this is better suited for your application.
I am thinking about taking my GM tube out and making a housing for it and us it as a remote, having a tether of 4-6 foot long. Thoughts?
Perhaps use a telephone type coiled cable. I also thought about this a while ago, 3D printing a custom enclosure for the tube. Instead of using spring clips to hold the new tube 'wand' to the side of the device, I was thinking about using a magnetically secured wand and 3D printing the instrument-end magnet holder with a shape that matches the wand shape itself to ensure a better grip.
BTW, I have found that a cheap selfie-stick grips the device pretty well so this is also a nice option for ground surveys without the need to visit a orthopedic doctor afterwards.
I just did this to help with surveying the tailings heap of an old uranium mine - I'm currently working on that particular video...
I will be looking for that video.@@project-326
Wow! What a wonderful review. The FNIRSI brand makes all kinds of test equipment. Such as the: $165 FNIRSI DPOX180H 2 Channels Digital Phosphor 180Mhz Oscilloscope.
However , after watching this video I am leery of this brand. If they dumb down their products I will pass. 😎 Thank you.
I am actually wondering if this was done due to issues with the availability of the J321 tube. I bought my replacement J321tube for about $12 on Taobao, but the other locally made types are about half that cost on the same platform. Many GM tubes are made in Russia, so this might be impacted by the war in Ukraine. I say *might*, I don't have any hard data.
2:18 Always buy from the official store. Even then you get things with no branding, e.g. my RD Tech TC66 meter where there's no company name on the meter itself.
Typically, here in China, the unbranded version is made by the same factory as the branded one. This happens because the brand doesn't want to pay for the tooling and certifications and pushes those costs onto the factory but in return, the factory can then sell the product but not with their original brand customers' marque.
I could not resist to buy another of these, just to confirm the change of tube. And as you are writing, the replacement tube makes this unit a piece for the junk-yard! So folks: until Fnirsi change back to a usable tube - Dont buy! It appears that its a third, even shittier tube, HH614 in the one I bougt
Please tell me, what was the battery standby time with the original firmware?
I can't remember, I will need to put that back on and re-test.
@@project-326 asking because you said that with the new firmware it was only 16 hours, btw..the latest new firmware also has a dark theme.
@@ExploringWithJason It was a few days, but don't remember if it was about 3 or 7...
@@project-326 of it working and with the screen on?
@@ExploringWithJason the device wasn't being actively used so the backlight will turn off.
hey man, thanks for the video, wish i saw it sooner. I bought one and it doesnt work at all. Has the small tube in it but im lucky as the resistor is not there and the tube connectors for the larger tube are on the board as well. Im in Australia and was wondering if the j321 on ebay are legitimate? thanks
If you are going to buy tubes, best to buy new ones. Take a look at the Manutek4000 channel for the issues that can happen with eBay tubes. He bought J321's on eBay and they were all useless.
@@project-326 thanks, i went ahead and bought one off ebay earlier because i couldnt find any for sale in australia. Im hoping its not a dud
What was the voltage on the tube connectors
@@RWE870 It is kind of hard to measure that. Normal DMMs have an input impedance of 10M, which is in the same order of magnitude as the anode resistance. I don't remember exactly, but measuring before the anode resistor gave about 380 to 400V
I have 2 of this devices the first has the brand name fnirsi and has a j321 tube the second is blue colour the brand is joy-it from simac electronics in germany and has M4011 tube made in 2023 what is your opinion about this tube??? thanks in advance!!
The M4011 and the J321 are pretty much the same in all regards. The sensitivity is just slightly higher in the J321 but not by a significant amount...
@@project-326 thank you very much Sir greetings to China from Greece!
Did you add the 100nF cap in series with resistor or only the capacitor ? I tried first 2.2K and the sound was weak, then I replaced it with 100n cap. and the sound became even weaker, now I'm running with 2K, but the click sound is still very weak.
P.S. I ordered mine from aliexpress and it is with M4011 tube, google said it's the same spec. as J321.
The sound isn't the loudest, but there is a better solution. In this video I used only the cap. If you look on this channel you will find a video about a FW upgrade, which give very decent volume level clicks...
You are correct, there is almost no difference between the M4011 and the J321.
I hope that helps!
I have 2 of this the first is with name on it fnirsi and i opened it and has a j321 geiger muller tube the second is blue colour and brand is joy-it RAD01 by simac electronics it is sold in germany in conrad store and in other parts of europe like greece i opened it also and i was amazed it has a m4011 geiger muller tube made in 2023 what is your opinion about this tube in this device?
The is an OEM product designed by the factory and all of the ones you see with different brands, colors, etc are all made in the same place.
@@project-326 yes but no name have tge crappy j613 tube!! do you know information about the M4011 tube?? I found on google it is enough good
@@project-326 yes but no name have the crappy j613 tube!! The fnirsi brand has the j321 tube!! do you know information about the M4011 tube?? I found on google it is quite good
I heard someone also fitted a small solar panel at the back of the case. Neat but, given the weak current it gives, it'll take...quite a while...given my experiences with a panel that...small...
It's pronounced fuh-NEAR-SEE, but FixCo sounds better.
Thank you, very helpful!
Glad it was helpful!
Mine came with the j321 but still had the loading resister on it how did you remove the loading resister.
my advice is to not change it, it has been set to the correct value for the tube.
Hi... i go to.order j321, its the only thing to upgrad ?
What is a good cheap Geiger counter?
btw Does anyone know what battery pack connector that is? I want to replace it with an even larger one. Rad Pro firmware kinda cut down the battery life.
That was my first Geiger counter. Mine seems to work better than the unit you tested. …although not as sensitive to [Bs] as my Radiacode 103.
the changes that have been made to this product have occurred in the last couple of months, so you probably have the good version! It a shame that this product has now been hobbled in such an awful way.
oh for fuck sake, the 103 is out since 3 days and everybody seems to already have it, how the fuck is that even possible?
> t. Radiacode 102 owner
@@andreafavero4250 I know that horrid feeling. I only bought my RC102 a couple of months ago, and just before they reduced the price by $100. I seem to be particularly unlucky, a similar thing happened with the KC761 too. Fuckty-fuck.
@@andreafavero4250 The Radiacode 103 has just a bit better resolution. 8.2% ±0.4% FWHM (Full Width at Half Maximum) versus the 102 with 9.5% ±0.4% FWHM. You’ll need to be doing some serious Gamma spectrometry to notice the difference.
@@project-326it's alright my man, I actually bought two for the black friday event and I have literally zero regrets. It's not like the 103 makes mine less godd at what they do and yes, it's annoying that we didnt know earlier it was going to come out but I have no hard feelings agains the company, also because a product so well designed that can perform gamma spectroscopy shouldnt cost this little. And also I want to thank you thorough review that made me go for it. I absolutely love mine and I will give the second one to a friend of mine because he travels a lot and it will be interesting to see the radiation maps :)
I've just opened the device I bought from Amazon UK, and it's even worse with an even smaller tube inside. The tube inside is unlabelled and has double sided tape and foam holding it in place. Doesn't even have the mounting for a real GM Tube. I can show you the photos.
Yes, I have seen from the comments, the company has found an even cheaper GM tube, it looks like a Christmas tree light...
The pad for the J321 should still be present on the PCB and if you get a replacement J321 tube, it is supplied with the clips that solder into the board.
@@project-326 Yes that's it. You can guess my disapointment, I will attempt to fix this.
@@CrazyPeteUK Good luck with that, just reach out if you get stuck...
Thank you ever so much@@project-326
nice video!
Thanks for watching!
well now i feel so lucky taht my 2 fnirsi gc-01 order six mounth apart from each other have both the j321!!! thnak you for that review ! do you have a video about what thrshold value i should put in there?
I assume that you mean the alarm threshold， right？ I normally have mine set to 1uSv/h. If I'm in an area that has dose rates higher than that, I probably want to find out why...
@@project-326 thanks a lot that is very helpful!
@@project-326 also i must say that your english is excelent for a shenzen resident (coming from a french canadian)
@@offroadbaddude1 Actually, I'm British, my family is from a typical English south coast seaside town. Not sure if I will ever go back there though.
I have lived here in SZ for nearly 2 decades and during that time the UK has had more than a few collective 'brain farts' that has set the nation back by about 2 decades. So when I visit, it's like the land that time forgot...
@@project-326 well this explain that!! brain fart are common in canada too ... people's brain freeze in the winter so every spring they repeat the same mistake ... i rather stay close to my wood stove !!! maybe global warming is not a bad thing after all 😂
Thank you for save me wasting money but wich one should get??? 🤔
There are a bunch of reviews on the channel page, please take a look. Perhaps start with the FS-5000 review...
there must be 2 versions randomly sold. one with the original tube and one with the smaller tube. i bought it a week ago from fixco and it has the big tube.
I think it has a lot to do with which vendors are holding stock of the older devices. Typically, the guys with the older stock will be motivated to sell quickly by lowering their prices. Money tied up in stock for these small 'nobody brands' is pretty tough to deal with, and frankly if they are just drop-shippers, they won't know which model is which, which model has a good tube and which has a $hitty one (they probably didn't even see, or test, a single sample of the product before buying several thousand of them, they typically just look at Amazon sales numbers for other brands selling the same OEM product).
If so, one element that was unclear from your upgrade video was what to do after removing the extra loading resistor. Leave the space empty? Solder a different resistor? Connect the terminals with a plain piece of wire? Sorry, I have only a basic theoretical understanding of these things, but certainly not a practical one!
Also, are there any precautions to take when taking the meter apart, so as not to break anything? (Edit - no, there are just 4 screws, which are retained in the housing, so you don't lose them. The battery is on the back panel and connected with a couple of wires, but there is lots of room.)
Update, I opened mine up, and it was an easy process. I discovered I have an even smaller J613 tube (the new board is designed for it , as there is an outline for it). There are connection holes for a larger tube, I think, but will they be connected on the under side of the board? And will the 321 come with a pair of holders that fit? Also, it appears the loading resistor you removed in your previous video is no longer present. I wish I could post a photo.
I have seen an updated PCB design that used the even more crappy J613 tube, the race to zero, on this product design continues unabated. In the end, I used a 20M loading resistor on my device.
isnt .2 to .3 microsieverts on the high side for background radiation?
i am thinking of upgrading my own tubes because mine was also originally reading an average of .1 and i thought it might also be underreading levels but everything ive read says .1 should be around the average for bg radiation
Indeed it is, after making this video, I discovered that the loading resistor should not be removed but adjusted to match the PSU (the voltage is very erratic between devices). With a 10M loading resistor, the readings became a lot more reasonable. Here in Shenzhen, I normally see about 0.18 nSv/h when averaged over a reasonable period of time.
When I made this video, it was summer in this tropical region and the humidity was over 85%, but when the winter came, and with it the lower humidity, I noticed that the tube voltage was getting too high...
Would you be able to modify the firmware to add those features?
someone already did!
Please take a look on the channel for the GC-01 firmware upgrade...
If you make a firmware upgrade for this geiger counter or a plug in to computer, can you make it available to other owners? Thank you for information.
Actually, somebody else already did it. I am making a video about this firmware upgrade and the video should be finished in a day or so. Make sure you are subscribed to be notified when that is released.
12:17 where did you solder the other end to?
The LED output signal, sorry I didn't show that bit, with hindsight that was a little tardy of me. If you pause at 9:55, the other end is connected to R33, at the side that is shown downward in this photo. I will add this to the description, thanks for letting me know!
Because the capacitor results in a positive pulse at the beginning of the LED pulse signal, it will energies the peizo sounder via the transistor. If the alarm is active, the negative pulse at the end of the LED pulse, will cause the alarm signal to be briefly interrupted and this allows the particle sounds to still be heard, albeit, as interruptions to the alarm sound.
@@project-326 Ahh..thank you!
@@Tschubritza I have been asked to make a tutorial video about adding the particle sounds so keep a look out for that!
Thanks!
Hi, I just released a deeper dive video that explains the upgrade to add the clicks.
so I have to open my GC-01 to see which tube is there... if I find J613 I should replace it with the J321...
sorry for the late reply. That does depend upon if you feel that you can do the mod, I'm the ham-fisted type so I have to go really carefully with the soldering iron...
@@project-326 I had studied electronics in high school, I know how to assemble electronic circuits and how to do soldering...
@@lucasolari3756 - enjoy the process, it feels really good when you first test it after the hack, and the sensitivity is significantly improved.
ok, thanks! I would need clear instructions on how to do it... I have read that it is also necessary to recalibrate the high voltage that supply the tube and bring it to the manufacturer's recommended rating...
@@lucasolari3756 Don't worry about the voltage at first.
interesting… I bought mine labeled as Fnirsi a year ago and it came with the J321 tube. However have the resistor that you removed soldered to the PCB but it doesn‘t look reworked. Does anyone else have the J321 with the resistor in place?
Mine also has that resistor but looks reworked with Flux on the board still I'm considering removing it?
@@PlagueDoctorX312 Guess I need to get a radioactive source to test the measurements. Also wonder whether to remove it or not 🤔
My has some weird even cheaper version of that J613 shit tube. Weird because it is much shorter. It should be 85mm instead it is 51mm barely. Less surface area i guess even less sensitive... However it doesnt have thar rezistor soldered. Its empty. Maybe it is alredy modified power supply? Do not know if i can even use aftermarket J321 tube anymore. I can try to measure voltage however my multimeter impedance would load power supply therefore i will got wrong measurement. It would take oscilloscope with much higher imput impedance wich i do not have.
Same case, I have the J321 and that resistor is on the board. It does not look added on afterwards, though.
@@reflectivejellyfish They probably updated the manufacturing proces now. No need to modify anything. Units are coming cheaper straight from the line.
hello thank you for review i got for christmas its begin date is 01-01-2022 is that the j321 tube or crap???
thank you
Hi dude, no the J321 is the good version.
@@project-326 do you think i have j321 its almost a yr old i havent opened ty
For what it's worth, I just got one of these (box dated 2024-11-7) from the FNIRSI brand, and it looks like they reverted to the J321 tube, and have made a firmware upgrade to version 1.8 . . . (I have a pic, but Screwed Toobe won't let me post it . . . )
Gee, I thought it was a PoS just because the clock resets to Default every time I turn it on!
Some of them (mine for example) comes with a separate back-up battery which keeps the RTCC going. But the clock is really the minor concern...
Hi thanks for doing this video. I had ordered one of these on Amazon before seeing your review. On recieving the item i opened it up and it appears to have a J321 tube so at least thats something. Im not sure if its a goid idea for me to go at it with a sokdering iron as ive never really used one. Something i would like to know is more about the setting in the device. I bought it more out of curiosity than actually needing one but i have no idea about the readings. Also is there a more in depth video of fitting the upgrade to gain the audio clicks?
Im looking at is as a bit of a project and a learning tool.
Can you recommend a type of sample to test it with too please?
Hi David,
Thank you for the comments and questions. The first thing to say is "if it ain't broke, don't fix it".
As for other videos, there are a couple more on my channel, but look around on the channel page (I don't have many videos), there is one for a firmware upgrade, that might be of use to you.
You remind me of myself "I bought one out of curiosity" and now "where can I find test samples?". I think that many of the folk who are regular viewers found themselves with a new hobby through exactly this process! :-)
E-bay is a good source of test samples. Be careful buying uranium glass, much of it is fake but things like ionization chambers from smoke detectors and alike are useful sources.
What is cheapest reliable geiger counter?
That's a really difficult one to answer, it really depends upon what the application is. With low-cost devices, there is always something missing from the spec...
I got mine and i can confirm it uses even more cheap and shit tube that already discounted version J613. It doesn't even has a name. I found it on Ebay as simply "HG Geiger Counter Tube". Looks simillar to J613 but is is much shorter instead 85mm inlength its around 51mm. Even less surface area = even less sensitivity. However it doesnt have that loading resistor on PCB. Maybe it is alredy modified power supply? Do not know if i can even use aftermarket J321 tube anymore.
Did you figure it out? I bought one too and it has a tube 47 mm in length, again with no markings. Mine doesn't have a loading resistor either.
It seems that they changed the board design: the tube is properly mounted with it's leads going through the board, around the halfway point. The PCB markings for the J321 tube are still there though.
@@oskarantola2616 I since bought another radiometer. Pripyat RKS 20.03 Polaron Dosimeter with two tubes SBM-20 side by side. Much older and higher price but also much more sensitive and quite respected among the community of users. Still planning the upgrade the FNIRSI one even might be able to measure the voltage with hi impedance oscilloscope in work. Will see how it goes. Will report here if successful. PS by the description you have the same tube as me. Was your in some way secured to PCB other than just by wires? Mine was on wires on one end and flipping in the breeze on the other end of the tube. I put some double side tape under it to stop it from vibrating the wires. They would eventually break I suspect.
@@josifvissarionovich5320 Looking forward to it, hope you're successful!
Mine already has some double-sided tape in between the tube and the PCB from the factory. Does your PCB have markings for the smaller tube, too?
Also, I measured that the high voltage does still come to the J321 fitting contacts so perhaps this isn't a lost cause.
The little tube seems to fit the description of a HH614 GM tube, though no markings. The recommended operating voltage for the HH614 is 420 V, which gives me hope that the power supply might have enough voltage for the J321.
@@oskarantola2616 So is mine, bought 2024, Feb. 1st on amazon: About 50mm short tube without any markings. No fuse type holders, directly soldered to the PCB. No loading resistor. I measured about 320 volts at the tube with a DVM. Today I installed a J321 tube without any changes at the HV stage. The GC-01 has about 5 to 8 times better sensitivity. With the short tube readings were about 2-3 times less than a BR-6, no it is about 5 times more than BR-6. But on normal radiation a reading of ~0.50uSv/h is much too high (BR-6: 0.10 uSV/h).
@studio326- thank you for that very good video!!!
@wolf1403
@@wolfganglehmann2717 Does this mean that the meter isn't calibrated correctly for the J321 anymore?
Could the problem be fixed by installing an older firmware?
If I open it and it comes with the one it was originally designed to have, does that mean Its alright? Or do u think stock from them is still gonna be horrid
if it is already a J321, then its fine. It ain't broke, no need to fix!
My FNIRSI GC-01 has the J321, made in 2023. Lucky.
How can I find date of mfg? Nothing on box or packaging or unit. Start time says 2022. If I open it can I return it? Hesitant about opening! Thanks!
That is catch 22, the date code is usually recorded on the PCB. That said, this company has chopped and changed between tubes, so the only way to he sure is to open it up and look at the tube.
I guess the logic could be as follows: If it is a J321 tube, then there is no need to send it back. If it isn't, you could always update it?
;-)
@@project-326 Thanks for the reply! I did decided to open it up, and it has the J321 tube, just like the pic in your clip above. Also, there was no center screw, just the four corners. Maybe this is a newer update?! I don't have any standard sources to check, but it did agree with the readings taken via a radiation safety Geiger Mueller counter.
Hello, in your video, you're saying that you replaced the loading resistor to the just level, how exactly did you do that? What was the right level?
For the J321 tube, I needed 480 volts to be in the 'sweet spot'.
I bought my product named GC-01, on 03.08.2024, it even has FNIRSI GC-01 printed near LCD, however it uses vastly different board. it doesn't have supporting pins fot the tube at voltage outputs, it uses some nameless tube (maybe J613). Is there any possibility of perhaps mailing You the photos, so You can judge, if it's possible to mount the J321 tube on this board ?
project326@qq.com
can you do a tutorial on how to add the sound?
Oh, that could be a body of work. Perhaps I can do a short, would that work for you?
Thanks - saved me wasting my money on buying one.
Just got mine few days ago, i do have the J321 tube but the resistor you mentioned is also there, should i attempt to remove this? The only other rework i see on my pbc is they added a nice battery holder for the cr1220
if it has the correct tube, then don't change anything, the resistor has been matched to the tube.
I have seen several different values for the load resistor in the comments, the one on mine was originally very low and thus pulling the tube voltage too low for J321 to correctly operate.
Do you get normal readings for background, etc?
@studio326- 18cpm which is probly normal, I'm just getting into radioactive materials just starting to learn.
@@PlagueDoctorX312 its a hobby that rewards with knowledge, but can also snowball into a seriously time consuming activity. Enjoy.
@studio326- just making a assumption on that resistor, that it must be for calibrating the tube?
@@PlagueDoctorX312 It will be for matching to the tube type. This is just to make sure that the tube is operating correctly (Geiger mode).
The calibration, ie counts/min to uSv/h will be in the firmware.