Hi From Norfolk UK

Hi I am new to this just got my kit a tube not yet setup. The kit is from RH electronics RH-K-GK-1-A the tube is a sbm-20 (CTC-5)
andy

Thanks for everyone's help now all up and working. I now just need to put it all in a nice box and tidy all the bits. Two bits of info I do need is what can I put the tube in to keep the water out but not make it insensitive. How long can I make the leads to the tube, I wont the tube outdoors but the electronics indoors. tnx andy.

If an SBM20 tube, just seal it inside a thin plastic or ABS tube, even a pill bottle. Weatherproof with tape. My GK+ cathode sensing has an LND712 probe on a metre long cable. Even two metres probably won't give to great a voltage drop. Just check the anode voltage before you seal the GM tube. With a gigohm resistor on a 10 megohm multimeter probe, you should be looking at around 4.XX voltswhich multiplies up to around 400. I'm assuming the electronics allows you to adjust the HV.
Depending on the GM tube, any weatherproofing is going to leave you reading cosmic rays and gamma radiation, unless some dust with an isotope with high-energy beta particles falls on the protective sleeve. I imagine that with a glass tube like the SBM20, you could improvise a plastic holder with the connections insulated and sealed, a portion of the middle exposed to air, rain and wind.