4yanx, I don't think this animal exists because you see. the idea behind twinlead has to do with the (elimination of) the capacitance between the two wires by spacing them apart a certain mimimum distance. If you were to throw a shield around it, you would literally short-circuit that (300 ohm) design.
What you need to do is attach (right at the antenna) a 300 ohm to 75 ohm inline transformer. Very common and no more than $1-4 at Radio Shack etc. You attach the twinlead pigtail coming out of the transformer to the two antenna terminals and then attach regular (shielded) coax cable to the other end and you're in business.
What you need to do is attach (right at the antenna) a 300 ohm to 75 ohm inline transformer. Very common and no more than $1-4 at Radio Shack etc. You attach the twinlead pigtail coming out of the transformer to the two antenna terminals and then attach regular (shielded) coax cable to the other end and you're in business.