Re: Oleheur 35
the tube is basic electric conduit on the one my pops and I have. Call them up and they can help you get another tube going or read ahead.
You can alter your tube length on these for more accurate readings. Simply dimple the conduit at the proper spots so the screens can index when you tighten them down, but remember that if you don't measure accurately the readings will be forever off. If it is set for a foot between screens, then dimple at exactly zero, 1 foot and 2 feet on the conduit with a bit of overhang before the end marks (both zero and 2 foot). To dimple simply use a center punch, same as for drilling metal. I'm not 100% sure what we have ours set to for spacing, but I think it's a foot between screens.