The source I use to test my Geiger counters (actually just one, and I switch the GM tubes) is a plastic bag with 3 NOS gas lamp mantles. They are quite hot. I haven't had any luck (or perhaps that was actual luck) trying to detect natural radioactivity at the places I have access to, so every time I take my Geiger counter somewhere, I have to take the mantles too just to show that the counter works.
> What kind of GM tube is in it? My entry-level scintillator gives me a background of ~1150CPM at 900V. A scintillator? Wow! That's serious stuff! :) On Tuesday, October 27, 2020 at 11:24:11 AM UTC-3 Robert G. Schaffrath wrote: > Back in the late 1970's, I purchased an old ARC-44 radio that came with a > warning about Cobalt-60. Seems the 5829/WA and 5787/WA tubes contained > Cobalt-60. However, with a half life of 5.3 years, the tubes showed no > activity on a Geiger counter. By the time I got the radio as surplus, three > half-lives had already passed. > > On Monday, October 26, 2020 at 6:53:14 PM UTC-4 Pramanicin wrote: > >> I received a box of dekatrons a couple years ago where some of them had >> radioactive labels on the boxes. Just standard GC10B's, so not sure what >> the label was warning me of, alas I don't have a geiger counter, but maybe >> I should get hold of one! >> >> On Mon, Oct 26, 2020 at 3:35 PM Paul Andrews <[email protected]> wrote: >> >>> Mine is a GK Mini with a SBM20 tube. Background with it is about 20 CPM. >>> >>> On Oct 26, 2020, at 6:12 PM, Mac Doktor <[email protected]> wrote: >>> >>> >>> >>> On Oct 26, 2020, at 5:35 PM, Nick Andrews <[email protected]> wrote: >>> >>> Haha, the radium is the one that makes me nervous. Tritium, Kr, etc not >>> so much! Just watched Radioactive on Amazon (I think) about Marie Curie. >>> A little slow but not bad. >>> >>> >>> I read somewhere that the Curies would go out to their workshop after >>> dark and just stand there watching the entire room glow. There were glowing >>> rings on the shelves where bottles had been sitting at some time in the >>> past, who knows how long ago. >>> >>> >>> On Oct 26, 2020, at 6:00 PM, Paul Andrews <[email protected]> wrote: >>> >>> I have a couple of old alarm clocks with radium dials. My Geiger counter >>> goes crazy when it’s next to them. >>> >>> I also have some Uranium glass glasses and was surprised to get about >>> 20-30 times background off of them. >>> >>> >>> What kind of GM tube is in it? My entry-level scintillator gives me a >>> background of ~1150CPM at 900V. >>> >>> >>> My dad had prostate cancer a while back. They implanted something with a >>> half-life of two or three weeks. I checked him every half-life to confirm >>> that the count had in fact decreased exactly 50%. 8D >>> >>> >>> Terry Bowman, KA4HJH >>> "The Mac Doctor" >>> >>> Q: Should car stereo speakers be pointed to the rear for more thrust or >>> up for more traction? >>> >>> A. On long trips, the 20- to 30% improvement in gas mileage you might >>> get with speakers pointing to the rear is certainly worthwhile. On the >>> other hand, if you drive on snow or ice, the extra traction of >>> speakers pointing upward gives you added control. >>> >>> Don Lancaster >>> >>> -- >>> You received this message because you are subscribed to a topic in the >>> Google Groups "neonixie-l" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/neonixie-l/BL83MEnFSbA/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/A1A1E624-DE2B-4946-942D-58D48D37EA53%40gmail.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/A1A1E624-DE2B-4946-942D-58D48D37EA53%40gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >>> >> You received this message because you are subscribed to the Google Groups >>> "neonixie-l" group. >>> >> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/9269EE17-C181-47C9-BAED-EFEAE9ACAA5F%40gmail.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/9269EE17-C181-47C9-BAED-EFEAE9ACAA5F%40gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/42cfeedf-c14a-404c-8280-d137259b0072n%40googlegroups.com.
