I have a 30ft coaxial cable. Shielding and main conductor are isolated from each other at both ends. Cable is not connected to anything at either of the ends. One of the ends is on the roof and the other is in my room. The reason for being disconnected at both ends is preventive against lightning strike. It has happened three times, as far as I can remember, that when I touched the cable in the morning I got a slight shock like the one you get in winters by touching metallic items. Moreover, when the conductor of this cable is brought in contact with something metallic item, a visible discharge is clearly seen. The end on the roof, though not connected to anything, has the man conductor peeled off for about 27 cm and serves as an antenna for a radio receiver. I have a few questions:
1. Why is it happening?
2. Are the two conductors and the insulation between them are acting as a capacitor and storing electrical charge from atmosphere?
3. What can be done to prevent it as I need the peeled off end to serve as antenna, which otherwise is doing well as an antenna?
I will be grateful for all the help I could get. Thanks.