Hi!
I bought an SBM-20 tube via ebay and something is rattling inside. Here's a video:
http://www.bksys.at/bernhard/geiger-cou ... ure-18.mkv
It's actually a more faint rattling, just the microphone of the webcam picks it up so well.
Is that normal for an SBM-20? The tube works fine otherwise - at least I think so. I had circuits where it would produce a bursts of noise/squeaks instead of sharp clicks, but with my current schematic it's much better.
Sorry that this is not about your kit, but you seem to have experience with SBM-20 tubes.
Thanks, Bernhard
PS: Here's a video of the clicking counter:
http://www.bksys.at/bernhard/geiger-cou ... ure-25.mkv
rattling SBM-20
Re: rattling SBM-20
Bernhard,
It's not normal, but I have a few tubes that rattle. A couple of them will register false impulses (clicks) when I shake them. I'm not sure if what is loose inside the tube, as I have not cut one of them apart, but I suspect it might be broken pieces of the glass end seals.
If you don't disturb the tube you should be fine, but I don't know how the debris inside will affect the sensitivity of the tube.
For this reason, I don't ship any kits with tubes that rattle, and after noticing the sensitivity to shaking I no longer use them in demo units either. Instead, they are in a box of bad tubes that I occasionally steal end-caps from.
It's not normal, but I have a few tubes that rattle. A couple of them will register false impulses (clicks) when I shake them. I'm not sure if what is loose inside the tube, as I have not cut one of them apart, but I suspect it might be broken pieces of the glass end seals.
If you don't disturb the tube you should be fine, but I don't know how the debris inside will affect the sensitivity of the tube.
For this reason, I don't ship any kits with tubes that rattle, and after noticing the sensitivity to shaking I no longer use them in demo units either. Instead, they are in a box of bad tubes that I occasionally steal end-caps from.
Jeff Keyzer
http://mightyohm.com
http://mightyohm.com