> > Nothing bad happens if you leave the balun out, Peter! > > Sometimes we over-complicate things. A balun is a good example. All that's > needed to produce a balanced "feed" is a length of transmission line (1/4 > wave or so) and a balanced load. If you have those things, it doesn't > matter > whether the output from the rig is "single ended" or "balanced", the > currents at the balanced load, such as the center of a dipole, will be > balanced. >
I played around with this idea this past summer and fall (at Ron and Don's suggestion) of using an open feeder fed directly to my KAT2. I put up a 66' doublet about 30' high in some trees in my front yard. I fed it with 33' of open line I put together with wooden dowels as spacers. As you might imagine, it tuned up just fine on 40m. In fact, I could tune up fine 80m - 10m with some problems on 20m and 17m. I then made some open feeder stubs for those bands that would bring me to some 1/4 wavelength interval and then I could get them to work FB. As Ron said, it is hard to measure the efficiencies on air. All I can say is that I would wait to get my sig report and reciprocate and then tell the other station I was running 5 watts. Many times I would get a "wow - you have a great sig out here for only 5 watts". Most of the time I operated in the mid - late afternoon - mostly on 40 and 20m. Many who answered my CQ were running 75 - 100 watt stations and commented how well my K2 sounded at their QTH. I know this is all subjective - but is indicative that feeding the balanced feedline, with a little care, with the unbalanced output of a KAT2 or KAT100 can be accomplished and can be highly efficient. I did operate with the BL2 also, but running 5 watts, never noticed if I was heating up the balun or not. Not sure if I could or not. With Ron's suggestion to remove the balun (with the mindset of - why put something in the antenna system inefficient if you don't have to) it seemed to me to not only work, but work well. YMMV. So thanks, Ron, Don and others on this list. It was a fun (although not very scientific) experiment which I plan to do again when the weather warms back up in the spring. I'm also playing around with the idea of bringing an open wire feeder into my shack as well. I may play around with a balanced tuner design as well. 73, Dave W8FGU _______________________________________________ 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
