Simple Ham Radio Antennas

KH6JRM's Amateur Radio Antenna Topics: A 20, 15, and 10 meter segmented inverted vee dipole. In my last post, I described a 40/15 meter inverted vee dipole using aligator clip leads and short pieces of wire to improve the SWR on 15 meters.  The short additional length of wire on each end of the inverted vee lowered the SWR for 15 meters and provided a slightly better match for the RG-8X coax used as the feed line.  When I wanted to use 40 meters, I just unclipped the short lead.  By selecting the correct length of wire for each band and using the clip leads to add or subtract a small amount of wire length, I was able to use this antenna without an antenna match or tuner. This past weekend, I was able to modify this idea to get an inverted vee that would cover 20, 15, and 10 meters without a tuner.  As in the case with the 40/15 meter inverted vee, I incorporated some ideas from Edward M. Noll (W3FQJ) and Larry Barry (NV5I) to make a homebrew tri-bander inverted vee that has

KH6JRM's Amateur Radio Antenna Topics A simple multiband inverted V dipole for 40 and 15 meters. If you have a small backyard and only have room for a few antennas, a segmented inverted V dipole covering two to three bands of your choice is an option worth considering. It is quite easy to build an inverted V dipole antenna for two-band operation, with each leg of the dipole separated by a ceramic or plastic insulator.  A jumper clip associated with  each of the two insulators is closed for 15 meter operation and left open for 40 meter operation.  While 15 meter operation is possible with just a 40 meter inverted V (using the third harmonic of your 40 meter frequency), you could risk high SWR on 15 meters, depending on what 40 meter frequency you use. For example, a few years ago, I used my coax fed 40 meter inverted V on 15 meters with few problems since my prime 40 meter frequency was 7.088 Mhz ( the frequency of the Hawaii Afternoon Net).  With the antenna cut for 7.088

KH6JRM's Amateur Radio Antenna Topics: A Simple 15 meter vertical dipole. Like many of my fellow amateur radio operators I'm "horizontally challenged" by a small lot without many trees or tall structures to support a half-wavelength, flat top dipole.  So, I've usually resorted to inverted vees, small loops, and random length wires.  All of these antennas have performed well, considering the lack of space available.  I've also tried verticals, with uneven results.  With a good radial or counterpoise system, vertical antennas can do a good job.  Perhaps, I'm getting old, but I don't get excited putting radial wire in my backyard.  Although I've used elevated counterpoise wires with some success, I just don't enjoy running wire all around my back yard, especially with neighbor children and pets running around.  Besides, the ground conductivity in my area is very poor.  The thought of "planting" a large number of radials in my small

KH6JRM's Amateur Radio Antenna Topics A limited space 40 meter dipole. The half-wave length dipole fed with 450-ohm feedline (the classic "doublet") is a basic antenna that will give you hours of enjoyment and plenty of DX if the flat top is at least 30 to 50 feet (9.14 to 15.24 meters) above ground.  Even at lower elevations, this simple, inexpensive antenna will provide strong local and regional coverage with a minimum of effort. But, for those of us who face space restrictions (not enough back yard or oddly shaped house lots), getting a    horizontal flat top working can be a problem.  Like many amateur radio operators, my backyard is small and erecting two masts approximately 66 feet apart (20.12 meters) is not feasible.  Is it possible to shorten the horizontal length a bit and drop off the remaining portion of the dipole perpendicular to the flat top and still get decent performance? According to Joel R. Hallas, W1ZR, you can modify the horizontal length an

A SLIGHTLY NEW BEGINNING: Welcome back to my original Amateur Radio Blog, which has been retitled:  KH6JRM's Amateur Radio Antenna Topics. This blog has been idle since late 2012 because of my changing job situation and the expansion of my original blog topic to include the latest Amateur Radio News. The news blog began early this year using my original title: KH6JRM's Amateur Radio Blog (http://kh6jrm.com). When I started reporting Amateur Radio News, I found the task complicated by an oversupply of information and a lack of time to follow my experimental antenna ideas.  The reaction to my news blog has been gratifying and I refer those interested in the latest Amateur Radio developments to access that site. I've also received some notes about my neglect of simple antenna ideas--a subject that was the original focus of this antenna blog.  So, I've split my interests into two blogs that will hopefully answer both inquiries.  My revised antenna blog will be fou