To: qrp-l@mailman.qth.net Subject: Re: [QRP-L] Walking Stick Antenna From: Michael Babineau Date: Wed, 1 May 2013 19:44:23 -0400 List-post: mailto:qrp-l@mailman.qth.net> Mike et al : With the 20 foot "crappie" pole I use a 20 foot length of TV twin-lead, with both leads stripped and soldered together at the top to make a 20ft long vertical wire. I put banana plugs on both of the leads at the bottom. For 20m and 30m, I use it as a "fat" vertical by connecting both of the banana plugs together and working that against some 16 ft radials on the ground. A tuner will easily matcha 20 ft wire on 20m and 30m. On 40m the trick I use is to leave one of banana plugs disconnected so that what I have is a 40 foot long wire vertical that is folded back on itself, with the far end unterminated. The linear loading effect allows the 20 feet of twin-lead to be easily matched on 40m with a tuner and with quite good results. (Normally you would need a vertical wire about 24 to 28 feet long to easily match on 40m. ) I have been using one of these made out of Radio Shack Indoor twinlead and have made hundreds of QSOs with it from the field. I tried many different ideas to get a 20 foot wire to match easily on 40m and this is by far the most simple and effective (20 feet of indoor twin-lead only weighs ounces). The Pomona BNC to Banana/binding post adaptors facilitate this, as you can connect two banana plugs each, to both the black (shield) and red (center conductor) of the BNC. The radials get connected to the black plug on the pomona and moving between 20m/30m and 40m only involves connecting (or disconnecting) one of the two banana plugs from the red terminal on the pomona adaptor and retuning the tuner. No feed line is used between the twinlead and the tuner... the twinlead and radials are connected directly to the tuner (this works great with Elecraft rigs such as the K1/KX1/KX3/K2 with internal tuners BTW). Cheers Michael VE3WMB P.S. I had had many people ask "doesn't having the wire folded back on itself cause signal cancellation"? The answer is no. It does introduce a slight asymmetry to the radiation pattern but it is still essentially omni-directional. Besides everyone has heard of the idea of building a folded dipole out of twin-lead and that works just fine. This idea is not much difference, essentially it is half of a folded dipole that is non-resonant (i.e. only 20 feet long for the half length) and oriented vertically and worked against some ground radials, with a tuner at the base to match it. P.P.S. I have even used a 14 foot version of this antenna on a 13 foot crappie pole for pedestrian mobile operation. It will match ok on 40m with a trailing 28 foot drag wire and makes for a pretty simple and lightweight setup.