Bruce N7CEE wrote: I'm currently using a 58-foot end fed wire with 50-foot counterpoise. The SWR came out at 1.4 on 80m, 1.8 on 40m, and 1.0 on 30 and 20m. That's the best I've been able to do with an end-fed wire so far.
-------------------------- Nothing wrong with that. Any SWR less than, say, 2:1, is probably FB. An SWR of 1.5:1 or better is "perfect" for all practical purposes. The point to remember is that the SWR says nothing about how well the antenna radiates. It only indicates that the rig is able to deliver RF into the antenna and ground circuits efficiently. A 60-foot radiator is a pretty good compromise for the KX1. It'll show a good radiation resistance on 40/30/20 meters and it'll be a lot better than most temporary radiators on 80. When working with electrically short radiators (less than 1/4 wave), a *poor* "counterpoise" or other RF ground will usually *improve* the SWR obtained. That's because the radiation resistance of such antennas is quite low. A 1/4 wave is about 35 ohms, but the value drops very quickly as the antenna is made shorter. It's not unusual for the resistance to be below 10 ohms or even less than 1 ohm in many cases. Since the ground resistance is in series with the antenna, having a poor, high-resistance ground brings the value up to help the ATU find a match with a low SWR. That's the good news. The bad news is that with a fairly high ground resistance, most of the RF is consumed in making heat in the ground circuit instead of being turned into electromagnetic waves by the radiator. What you've accomplished is to have a decent radiator length that improves the efficiency AND you've accomplished a low SWR for efficient power transfer from the rig to the antenna. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
