On Tue,4/18/2017 10:10 AM, Guy Olinger K2AV wrote:
Then there is the loss based on number of spacers and loss tangent of the spacer material modifying the lesser air loss.
Below UHF, loss in transmission line is virtually all due to copper losses unless the dielectric material is wet or is otherwise made conductive.
Quite a few years ago, N6WS did some excellent work showing that losses in window line are greatly increased when it is wet. His work was published in QST and later included in Antenna Compendium #6. It should be required reading for anyone considering window line. He measured four types of window line and some open wire line he built himself. Putting some numbers to it, Wes's measurements showed loss at 50 MHz increased from about 0.4 dB/100 ft to more almost 6 dB/100 ft when it was wet. The open wire line showed no increased loss when wet.
73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
