This utility program shows the impedance and SWR at both ends of a transmission line and the details of power loss in the line. It includes characteristics for over 40 built-in line types. You can modify these values to see how small changes affect the results or to specify custom lines. All program inputs may be changed directly or you can use spin buttons to make the changes. If you are using a moderately fast computer you can hold down a spinner and "watch the movie" on the charts as the results are recomputed.
The stand-alone version of the Transmission Line Details program includes a plot function that allows you to see the matched line loss over a wide frequency range. You can experiment with changes to the K1 and K2 coefficients to see the effect on loss at various frequencies. You can also compare one line with another. The screen capture above shows LMR-400 compared with Belden 8267.
For more information concerning the K1 and K2 coefficients see the explanation given with the BestFit workbook.
Version 1.1, uploaded 20 Jan 2007, contains a more precise algorithm for calculating the characteristic impedance Zo of the transmission line at any given frequency. Zo is now computed using the "iterative RLGC" technique as opposed to the simpler "alpha/beta" method. This technique is explained in detail in articles by Frank Witt (ARRL Antenna Compendium Volume 6) and Jacques Audet (QEX Sept/Oct 2006), among others.
Download a zip file containing TLDetails (79 KB). Runs as a stand-alone program, does not require Excel. Free.
Important: This version of Transmission Line Details runs as a stand-alone program, not as part of a larger Excel workbook. However, it makes use of certain components that are found in all Microsoft Office applications such as Word, Excel, Access, etc. If you have not installed any MS Office programs (97 or later) you will see an error message concerning "FM20.DLL" when attempting to run TLDetails. The solution is to install any Office product, such as Word, on your computer. Alternatively, you can install a free Microsoft program called ActiveX Control Pad which will also install FM20.DLL.
If you see an error message about "MSVBVM60.DLL" you will have to download the complete Visual Basic runtime library. This is a large file so I don't keep a copy on this site. You can get it directly from the Microsoft site.