This shows the 2004/5 probe case open. We used a simple superglue seal on the precision milled join surface.

The 2004/5 verion used a stack of three PCBs, from left to right: radio, digital and analogue.

The 2006-7 design used a single PCB to save space and a Radiometrix radio module to reduce radio frequency to 173MHz and increase their range. The antenna is tuned to ice.

This is the 2008 probe pcb as deployed in Iceland - the new 3d accelerometer is lower left. It also had an improved low noise power supply and 0.6 microamp sleep current.