I just posted a model for an adjustable feedline impedance based upon my previous thread of why a wire feedline is better than a coax feedline for direct attachment of wire antennas, especially in the High Frequency (HF) band and lower frequencies.
Here is the link and I will add additional information over the course of the day :
Please be sure to see my other post titled "Why the use of ladder lines (twin-lead) is the better way to feed an HF dipole antenna than coax" for many good links on wire feed lines for dipole antennas !
If you don't receive the email within an hour (and you've checked your Spam folder), email us as confirmation@grabcad.com.