I have a section of air core Beldin coax, with the center feed separated by a
single wind of plastic insulator. The section is about 65 meters long. I added
enough RG58 to the feed end to get a full wave length. I then measured the
impedance using aa Autek analyzer. It read 30 Ohms.

The coaxpair program predicts for coax with a loss of about 10 db per km an
impedance of about 11.5 Ohms. The cable should be better then this.

Is this difference leaky or bad coax? Is it reasonable to assume water in the
cable? If it is water is there a practical way to get it out?

Thanks - Dan