Sources for SBM-20
  * [[http://sovtube.com/en/x-ray-geiger.html?page=shop.product_details&flypage=flypage.tpl&product_id=651&category_id=52|Sovtube]] - Denis has 500 pcs @ $19 ea. (Denis Moisyeyev <sovtubes@gmail.com>)
  * [[http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290555336425&ssPageName=ADME:X:RTQ:US:1123#ht_4100wt_1141|rus-market]] - 5 tubes for $130, $26 ea. Has 50 tubes as of 4/16.  Will take offers (ebay).
  * [[http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190522648783&ssPageName=ADME:X:RTQ:US:1123#ht_2384wt_964|SOVCOM]] - alexer1 will sell 100 tubes for $21 ea, e-mail rozen@te.net.ua.
  * [[http://gstube.com/catalog/9/|gstube.com]] - Anton has a very limited supply of tubes, does not expect more (4/16).  $43 ea.

Geiger Counter Plans / Schematics:
  * http://lcamtuf.coredump.cx/geiger/
  * http://brohogan.blogspot.com/2011/03/geiger-counter-kit.html
  * http://www.galacticelectronics.com/GeigerCounter.HTML
  * http://www.imagesco.com/articles/geiger/04.html
  * http://garden.seeedstudio.com/index.php?title=Geiger_Counter
  * http://www.seeedstudio.com/blog/2011/03/28/new-samples-of-gm-tube/
    * "Here we just got the samples of GM tube from Chinese military factory. They are J306β and J408γ, which are much cheaper than LND-712. Next we will try to make some prototypes and do some tests based on it."
    * http://dtzyc.b2b.hc360.com/supply/79902476.html
    * 200mm length is really long!
    * {{:people:jeff:geiger-tube1-300x294.jpg|}}
  * http://www.cooking-hacks.com/index.php/documentation/tutorials/geiger-counter-arduino-radiation-sensor-board
  * http://www.cooking-hacks.com/index.php/documentation/tutorials/geiger-counter-arduino-radiation-sensor-board
    * 95 euros with si-3bg (yuck)
  * https://sites.google.com/site/diygeigercounter/home
  * http://dtzyc.b2b.hc360.com/supply/79902572.html

Cosmic Ray Detectors:
  * http://www.flickr.com/photos/hardhack/sets/72157622062591940/

High Voltage Power Supplies:
  * http://www.edn.com/article/472194-High_voltage_low_noise_dc_dc_converters.php
  * http://www.youtube.com/watch?v=e9RX_UPownc
  * http://forum.pololu.com/viewtopic.php?f=6&t=1453

HV Probe Designs
  * [[http://ea4eoz.ure.es/hvprobe.html|One Gigaohm high voltage probe]] - Using a 1GOhm resistor and a ball point pen case!
  * [[http://repairfaq.ece.drexel.edu/sam/hvprobe.htm|Basics of High Voltage Probe Design]] - From sci.electronics.repair FAQ