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• SI-22G testing

  nrrdzilla • 03/09/2017 at 21:26 • 0 comments

  Incoming testing of the SI-22G tube was done, at work, using a Co-60 source in addition to background measurements. An off-the-shelf GM-tube supply was used, in order to get the bias low enough for this (giant) tube. Please see the files section for the incoming test data. There's also a photo up, now, that shows the slightly-dodgy wiring setup that was needed to bench test this tube.

  Bottom line is that it seems to work happily, and I now have a bit more of a push to get testing with the CCFL-transformer-based HV supply.

  Note: I'm starting to think that a different transformer might be a bit more sane with such a low bias voltage. I'm much more used to the 750~800V devices, like those made by the usual suspects like LND, Philips, Saint-Gobain, etc. which are much closer to the typical output voltages of these CCFL transformers.

  PS I'd completely forgotten, until yesterday, that I'd recently intercepted a coax cable heading for the recycling depot, with MHV connectors already on it. Photo of that critter is also posted.

  -Does it count as dumpster diving if it hasn't actually been tipped into the dumpster? Splitting hairs... ;)

• fun with 3D prints

  nrrdzilla • 03/05/2017 at 21:57 • 0 comments

  So... the latest picture attests to the fact that I had a 3D print test run. A few issues were high-lit, and there's an updated file on OnShape (see link above). I'm still working with Slic3r to try and improve the print, given that there's a bit of support needed around the perimeter, when printing upside down, and the screw holes need a good deal of extra plastic around them. But the batteries fit nicely... hehehe.

  This is great reading for anyone looking at this project:

  http://hackaday.com/2017/02/19/an-electronic-90v-anode-battery/
  

  http://www.dos4ever.com/battery/battery.html

  I was looking at driving my CCFL transformer using a TTL counter chip, because it's a state machine, and so I have control over valid states. That said; his ring oscillator stuff is so elegant :)
  

  So there :)

• base piece model underway

  nrrdzilla • 02/18/2017 at 08:59 • 0 comments

  Here's the base piece... this part is still a work in progress:

  https://cad.onshape.com/documents/16f7d96e75fbf5ac5831daa7/w/67b7b3a8fe5e4762c436ad20/e/7f3751909f21b9045d0211f7
  

  The intention is to have it 3D printed, so I can include slots to hold battery terminals for the 18650 battery (or stack of 2)

  This is the negative terminal I'm probably going to use:
  https://cad.onshape.com/documents/c25da064e829ff49b4182c16/w/1f7ff295f5cdafe13c14b472/e/854bc82a685523a38a3620c1
  

  More as time permits...

• Starting to throw stuff together...

  nrrdzilla • 02/18/2017 at 08:13 • 0 comments

  Ordered Russian SI-22G / SI22G Geiger Tube. Expected delivery around the beginning of March...

  Also pulled Solidworks model files, since most users prob won't have access to that. Will likely transition this project onto OnShape, here's the diffuser as a start:

  https://cad.onshape.com/documents/cc162031441e680698595b2a/w/eaa2b5ab492bdde8eaa25799/e/3cf96559478af369a68cae4b

  If someone could please check to make sure this opens OK, that would be great :)

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