On Mon, 2007-04-16 at 10:37 +0100, Alan B. Pearce wrote: > >As for connecting the coax to the antenna, this page has a helpful diagram: > > > > http://www.hamuniverse.com/slimjim.html > > > >No, it's not a short circuit due to the magic of RF weirdness. > > not just at RF either. Telephone engineers will tell you of notches in > frequency response, put into telephone lines by wiring left connected to a > trunk, but unterminated at the other end. > > A tutor I had during my apprenticeship courses used to tell how he would > really confuse the electrical students with an open wire transmission line > down the length of the lab. Light bulb on one end, signal generator feeding > around 400MHz into the line at the other, and part way down a stub coming > down onto the bench where there was a standard type knife switch. Open > switch, bulb goes out, short switch bulb comes on. Used to confuse the > electrical students who didn't know anything about higher than 50/60Hz, or > maybe 400Hz, how shorting the stub made the light turn on. > I've seen a demo of a open wire feeder made from small "festoon" bulbs... Some of them light up, others don't. Nice demo ! Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist