- Posted on
- • Geiger Muller Tubes
J306, J307 & J308 Geiger Muller Tube Background Comparison
- Author
-
-
- User
- Mr Blinky
- Posts by this author
- Posts by this author
-
I got these tubes just to see what they were like. I was a little surprised to learn that they are black due to a sleeve of heat shrink over the tube. I had previously thought they were black due to them being an opaque glass, but after peeling a little of the sleeve off it revealed tin oxide coated clear glass, much like the J305. I accidentally rubbed the markings from the J306 when cleaning it, as I have done on a J305. The markings come off very easy with these tubes.
Going from top to bottom - J306, J307 then J308.
Specs from Alibaba:
Below is the background comparison result. Each tube was left to run for around 30 days, although the first (J306) was short by a few days.
I think the graph says it all. This was a simple background test for each tube. I simply threw it on a counter and left if for days and let radmon.org log the results. The J308 seems a little underwhelming at around double that of a J305. The J307, despite it's length (it's the longest) was kind of miserable too. I initially expected something around 90-100 CPM. It seems circumference matters with these tubes. That makes sense, larger circumference, larger capture area. The J306 came out on top and gave similar results to a similar sized metal wall SI-22G. Prices were (all including tax and shipping): J306 - £24.59, J307 - £24.59 and J308 - £25.88. The J308 was bought separately, so the cost was slightly higher with shipping. The J306, J307 & J308 are all the same price from the seller, and I have to wonder why. AliExpress I guess! 😄 Bought from here: https://vi.aliexpress.com/item/1005005407840365.html
Archived from radmon.org - originally posted 06/04/2025
Add Comment
This policy contains information about your privacy. By posting, you are declaring that you understand this policy:
- Your name, rating, website address, town, country, state and comment will be publicly displayed if entered.
- Aside from the data entered into these form fields, other stored data about your comment will include:
- Your IP address (not displayed)
- The time/date of your submission (displayed)
- Your email address will not be shared. It is collected for only two reasons:
- Administrative purposes, should a need to contact you arise.
- To inform you of new comments, should you subscribe to receive notifications.
- A cookie may be set on your computer. This is used to remember your inputs. It will expire by itself.
This policy is subject to change at any time and without notice.
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
- Although the administrator will attempt to moderate comments, it is impossible for every comment to have been moderated at any given time.
- You acknowledge that all comments express the views and opinions of the original author and not those of the administrator.
- You agree not to post any material which is knowingly false, obscene, hateful, threatening, harassing or invasive of a person's privacy.
- The administrator has the right to edit, move or remove any comment for any reason and without notice.
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
Comments