Excellent point Joe. The current QST magazine that features a short article about running open wire or window line to coax outside the house and then using a short length of coax to reach the rig. The author noted that with a short run of 10 feet of the coax he uses, the losses with a 10:1 SWR would be about 1 dB at 28 MHz.
That sounds good assuming the coax losses and SWR are really that low in worst case. But what he missed was that he used a "choke balun" between the coax and feed line that consists of an additional 22 feet of coax wound up in a coil to keep RF off of the outside of the coax shield and so out of the shack. So he really has 32 feet of coax between the rig and the open wire feed line. If he original assumptions about maximum SWR and losses were correct, he's really losing about half of his transmitter power (3 dB) in that coax link and balun. Ron -----Original Message----- > Alternately, feeding through one or more half-waves of > coax will give you good accuracy while letting you get far > enough away from the antenna to not affect the measurement. Only if the feedline has zero loss. Force 12 are known for making their antennas "look better" by specifying the SWR through 100 feet of feedline. _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
