This is achieved by making the measurements at the receiver/transmitter end of the transmission line using the SWR analyzer and then entering the measured values into the TransTenna program. TransTenna will perform the calculations to determine the series resistance and reactance ( R and X ) at the antenna/load end of the transmission line. The calculations made by the program take into account the transmission line characteristics including length, velocity factor, characteristic impedance and cable loss. The resulting calculations are presented as series resistance and reactance ( R and X ) and include the SWR at the antenna/load end of the transmission line.
This technique of making the measurements at the equipment end of the transmission line allows antenna analysis to be made with the antenna in its operating location and not affected by the operators presence in close proximity to the antenna or by surrounding structures which may be required in order to allow the operator direct access to the antenna feed point for a measurement. Even lowering the antenna to a height where the feed point can be reached from the ground will yield different results once the antenna is raised to its final height due to the effects of the proximity of the ground and other objects.
Measurements can be made at any time there is a need to analyze the antenna without regard for weather or time of day.
TransTenna is not limited in use with any specific instruments and may be used with any type of equipment capable of providing the series equivalent resistance and reactance ( R and X ) at the receiver/transmitter end of a transmission line. A calculator is also provided for use with instruments which give only Impedance and SWR measurement data. This calculator will determine the equivalent series resistance and reactance ( R and X ) for use by the TransTenna program.
TransTenna uses the general transmission line equations and its accuracy is limited only by the accuracy of the data entered by the operator. In effect, TransTenna provides an easy to use alternative to the Smith Chart for transmission line analysis.
Download the TransTenna Installation and Operation Manual. This manual is 21 pages long and is a .pdf file. You must have Acrobat Reader 4.0 or higher to view the manual. The file is approximately 1 MB and may take several minutes to download. Please be patient.
TransTenna Manual
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