I tested out the GMC-300E from Amazon and was pleasantly surprised. This unit is about 1/2 the price of my Soecks and it seems to work pretty well.
https://youtu.be/Th8id-5aS4I
Where is gets cool is a commenter linked me to this site https://radmon.org/
The have a bunch of open source software and have a networked of linked dosimeters around the world. Neat collaborative project and a great use of everyone's Geiger counters when not in active use. Check it out.
Measuring radiation
Measuring radiation
I make videos and content on all things electronics, 3D printing and DIY
http://www.mkme.org
https://www.youtube.com/mkmeorg
http://www.mkme.org
https://www.youtube.com/mkmeorg