Simple Ham Radio Antennas

KH6JRM's Amateur Radio Blog Post #179 Portable antennas for the unexpected I've made it a habit over the past few years to keep an emergency "go" kit in my van in case I'm needed to provide communications backup for our local civil defense agency and the Hilo office of the American Red Cross.  Other than the 11 March 2011 tsunami (the one that damaged Japan and its Fukushima nuclear reactor), I haven't used my portable equipment that much, except for weekend operations in a local park or beach area.  When I worked at Pacific Radio Group, I kept an old Kenwood TS-520 and a Kenwood HT at the station for emergency backup to the Hawaii County Civil Defense office in Hilo.  But, since I retired, my forays into portable operation have been subject to personal whim or to opportunities I get handed to me. Such is the case this weekend, where I revert to my 22nd year as the tower announcer for the Big Island Auto Club's monthly points meets.  I'm under

KH6JRM's Amateur Radio Blog Post #178 Portable antennas One of the things I like to do when the weather is nice (such as today) is to drive my van up an old sugar plantation road and set up a low-power emergency station at a clearing above Laupahoehoe town.  At an elevation of 1,200 feet on the east slope of Mauna Kea, I have a clear view of the Pacific Ocean off to the northeast and a fairly good shot at Japan over the summit of Hawaii Island's largest mountain. Once I reach the clearing, I retrieve my homebrew 40-meter helix (see last post), 50-feet of 450-ohm ladder line, a 4:1 balun, the trusty Drake MN-4 tuner, about 10-feet of RG-6 coax, and the venerable Yaesu FT-7 qrp rig, which can be used for both cw and SSB contacts from 80 meters to 10 meters.  The vertical helix is comprised of two, 5-foot schedule 40 pvc pipes, which are joined by a pvc connector.  Sixty-six feet of #22 gauge hookup wire is wound in a spiral to the top of the vertical pole.  A 48-inch &qu

KH6JRM's Amateur Radio Blog Post #177 A modified fan dipole How would you like to make a simple, stealthy, and inexpensive antenna that covers 80 to 10 meters?  All you need is a local hardware store, some connectors, some RG-8 coax, schedule 40 pvc pipe, some copper plumbing straps, a few bungie cords, and about 250-feet of stranded copper wire. The details of this fascinating skyhook can be found in the 31 July 2012 edition of eham.net ( http://www.eham.net ).  Howard Gorman, W6HDG, has writen an article entitled "The Fence Fan Dipole (FFD)--A Quick, Easy, and Inexpensive Multiband Antenna." Howard provides detailed instructions and photographs to guide you in completing this project.  Most of the materials for his antenna came from a local Home Depot store.  Howard used a 12-foot fence around an old tennis court to support a 10-foot schedule 40 pvc pipe and ran antenna elements from a special antenna connector atop the pvc pipe.  He used bungee cords to atta

KH6JRM's Amateur Radio Blog Post #176 A compact 40-meter vertical There are times when a small vertical comes in handy.  You could be in a space restricted environment such as I where neighbors are almost back to back or you could be looking for an easily portable antenna useful for mini-DXpeditions or a casual day of operating from a park or beach.  There is a solution to this often vexing problem. If you have the resources, you may want to consider screwdriver antennas, adaptations of various mobile antennas (ham stick), or event the handy Buddipole sytem.  But if you're on a restricted budget and willing to "roll your own", you can find all the materials you need at the nearest hardware store. What I wanted to build was as a top-loaded "vertical helix" that could be erected in my backyard and easily hidden by bushes and trees bordering my qth.  Based on various readings in antenna literature, I found that if you wound a half-wave length of ordi

KH6JRM's Amateur Radio Blog Post #175 A "long wire" antenna One of the joys of being an amateur radio operator is the creation of antennas.  Since I live on a restricted lot surrounded by neighbors and high power distribution lines from the local utility, I have to be creative if I want to get on the air.  Like many of you, I've had to live with compromise antennas most of my amateur "career".  Sometimes, opportunities come along that just beg for experimentation.  Such was the case today, when several of my neighbors mentioned they would be visiting relatives for several days.  Since my teaching assignments won't begin until 01 August (or later, if you are a substitute teacher such as I), I offered to keep on eye on their homes until they returned. Goody!  There are several 30 to 50-foot trees in back of my house on my neighbor's property that just call out for antenna use.  Oh, well, that must be my imagination.  Anyway, I decided to str