As Vic pointed out, a center fed half wave (i.e. center fed "dipole") is probably the most efficient and easiest to erect, especially on 20 meters where it's only 32 feet end-to-end. Such an antenna provides a low impedance, letting you use coaxial feeder if you use a feed line.
Keep in mind that it does *not* need to be in a straight line. It can be erected in various ways. For example, if you throw one end over a tree so it drops vertically to the rig, the other half can run horizontally near the ground, making a very efficient "vertical". Such an arrangement will be somewhat directive in the direction you run the horizontal segment near the ground. Optionally you can use feed line and make an inverted "V" Skip the coax and use a reasonable length of 300 or 450 ohm window line for a feeder (just hook one side of the twin lead to the center pin on the antenna jack and the other side to the chassis ground) and you can use the antenna on any band from 40 through 10. On 40, where it's only 1/4 wavelength overall, it'll be 1 or 2 dB "weaker" than a full half wave, but that's pretty darn good. On higher frequencies you'll actually see a little "gain". . Ron AC7AC -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, July 06, 2008 5:38 PM To: [email protected] Subject: [Elecraft] K2 --- Park Portable Antenna Hi Vic; Your advice of launching a long wire into tree punched my "lets do something" button. I think I'll take my K2 out to the park next week and try getting on the air with a tree vertical as you suggested. Twenty meters should have some life in it and with this in mind, what form would this simple antenna system take? I have a KAT100 which I could take along to match it. Regards, Bob K7hbg _______________________________________________ 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 _______________________________________________ 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
