[Elecraft] coaxial dipole (was: What do you have in your portable/travel kit?)

[Dale Putnam]

And if you accomplish the very accurate building instructions from Brian, twice, and feed it as a dipole, but with a half wave wire fed in the middle, and add a quarter wave wire on each end, but make the joining very sturdy, you now have a very good, but low profile gain antenna on ?? what band were we building this for? I have mine on 20. It is fed with open wire and works just fine on 80 thru 20. 
  More details or if you want I will build one for you for cost. --... ...--Dale - WC7S in Wy> From: brian-wb6rqn at lloyd.com> To: gm4esd at btinternet.com> Date: Fri, 9 May 2008 14:53:55 -0700> CC: elecraft at mailman.qth.net> Subject: [Elecraft] coaxial dipole (was: What do you have in your portable/travel kit?)> > To make a coaxial dipole strip the external insulation from the end of > your coax to a length about 10% longer than 1/4 wave. This leaves just > shield (braid), center dielectric, and center conductor.> > push back a bit of the braid so it increases in diameter. Fold it back > over itself and carefully stretch it backward until it covers the > remaining external insulation leaving just the center conductor and > center dielectric exposed. The folded-back braid should now form a > cylinder over the coax. Trim this braid until it is 1/4 wave long. > Trim the center conductor until it is also 1/4 wave long.> > You now have a dipole that is end-fed. The folded-back braid functions > as both radiator and 1/4-wave stub to cancel the currents on the > shield of the coax. For 2M I put this whole thing in a piece of PVC > pipe and shoot in some foam insulation to keep things in place. It > works just peachy.> > Caveat: you may find that turning the braid inside-out to make the > outer element to be a real challenge. You can cheat by cutting the > braid off, compressing it so it slips over the outside of the coax, > and then reattaching it to the shield of the coax with solder. To be > honest, that is what I usually do. ;-)> > Brian Lloyd> Granite Bay Montessori School 9330 Sierra College Bl> brian AT gbmontessori DOT com Roseville, CA 95661> +1.916.367.2131 (voice) +1.791.912.8170 (fax)> > PGP key ID: 12095C52A32A1B6C> PGP key fingerprint: 3B1D BA11 4913 3254 B6E0 CC09 1209 5C52 A32A 1B6C> > > > > _______________________________________________> Elecraft mailing list> Post to: Elecraft at 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
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