June 2014 edition of
(pp38-40) has an article by
Joel Hallas (W1ZR) reporting on an updated version of the venerable Transmission
Line Program for Windows (TLW), by Mr. R. Dean Straw (N6BV).
The previous version was last released in 2006. Owners of the
ARRL Antenna Handbook receive the program on the included CD/DVD, and are eligible for a free upgrade
if you have a previous version. The Zip file can be
downloaded from the
ARRL website. If you are not eligible but would like to read the user's manual, download the Zip file and extract
just the PDF file since the one available elsewhere on the Web is for the 2006 version.
According to Joel's review, the main changes in TLW are refinements in the manufacturer's data used for curve
fitting and in the electrical parameter calculations. Results obtained from extreme source and load impedance
scenarios could cause some strange values of loss, voltage and current distribution along the transmission line,
I have managed to lose my CD so I cannot produce any examples of my own. However, the following couple images
are screen shots from the user's manual that might whet your appetite for the program. As far as I know, it is available
only with the purchase of the
ARRL Antenna Handbook, which is currently selling for under $50. The software itself is worth that
much if you require such calculations. According to Joel: "I can state that among all the programs and data on
The Antenna Handbook CD, I find Transmission Line for Windows (TLW)
to be the program that I use the most."
Posted on July 5, 2015