Roll Up J Pole Antenna Plans

91 no 3 pp.

Roll up j pole antenna plans.

36 dbj 2 commercial dual band roll up antenna kit 152 157 mhz and 460 470 mhz. The antenna can be set up quickly and easily by hanging out a window attach to a ceiling or toss a lead sinker over a tree branch with kite string and hoist it up. Harris a vhf uhf 3 and mobile antenna qst feb. Coax center conductor attaches to the long section feed point.

Enter the operating frequency. Unlike the popular ground plane antenna it doesn t need ground the dbj 2. I built the dual band j pole antenna from the article in the september 1994 new ham companion an easy dual band vhf uhf antenna page 61 but i just can t get it to work. Also includes a 6 ft extension cable.

A portable vhf uhf roll up j pole antenna for public service edison fong wb6iqn. 3 ounces compact and effective. To a portable roll up antenna. Ed fong wb6iqn also makes good roll up dual band j poles available here the dual band open stub j pole antenna built out of heavy duty 3 16 angle aluminum uhf so 239 connector with 3 8 aluminum elements and all stainless steel hardware.

J pole antenna design. The slim jim designed by the late fred judd g2bcx can be a great portable roll up antenna if made out of 300ω or 450ω ladder line twin feeder. Save time by using the calculator below. A portable vhf uhf roll up j pole qst march 2007 vol.

Principles of the dbj 1 the earlier dbj 1 is based on the j pole 2 shown in figure 1. Shield attaches to the short section feed point. A balun is necessary because a j pole antenna uses a balanced feed the. What can i do.

Maximum power input 50 watts. There are several features which make the ubiquitous twinlead j pole antenna a good addition to your emergency grab n go kit. When rolled up it is an extremely compact pocket sized antenna. Dbj 2 ham dual band roll up antenna kit 144 148 mhz and 440 450 mhz includes adapters for bnc sma and sma female.

Figure 3 ladderline j pole with and without feed line choke for the purists and since it matters in this discussion the view above is from the other side of figure 2 antenna and feed line are to the right of the mast. Fong us patent 8 947 313 radial free ollinear. Try adding a balun to the coax. The 2 meter roll up j pole is lightweight approx.

Design your j pole for hf 2 meters 220 440 and up. This simple antenna lends itself well to emergency use or as a portable antenna for hotel room operations while traveling. Since it is the second version of this antenna i call it the dbj 2. Add a loop of string to the top and hang it on a tree branch use it with your handheld transceiver then roll it up.

Includes adapters for bnc sma and sma female.