Why don’t we see simple ¼ wave 75 ohm lines used as a first step in matching a 140 Ohm Helix to 50 ohms? The ¼ wave line would give an easy 112 ohms and then it shouldn’t be that hard to do a little additional construction matching to get to 140? (building a 2.4 GHz pop-out helix that compresses flat for launch) Bob, WB4APR