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Antenna Topics: A simple inverted vee dipole that doesn't require a tuner, post #189

KH6JRM's Amateur Radio Antenna Topics: A simple inverted vee dipole that doesn't require a tuner. Hawaii Island has been enjoying some excellent, if somewhat voggy, weather the past few days--a perfect time to design and build a simple antenna for my favorite amateur radio bands.  Although I enjoy working 10 and 20 meters, I've found plenty of contacts and even some decent DX on the 40 and 15 meter bands.  During the day, there are plenty of Hawaii hams to chat with on a variety of nets.  Early afternoon chats on 15 meters range from locals to the exotic realms of the southwest Pacific and Japan.  If I decide to work 10 or 20 meters on a whim, I can always switch to my 40 meter vertical with tuned counterpoise to capture a few elusive contacts on 10 meters.  This antenna uses tuned feeders (450-ohm ladder line) and can work amateurs from 40 through 10 meters with the help of a 4:1 balun and a good transmatch, such as my Drake MN-4. However, this week, I've had th

Antenna Topics: A tuned counterpoise antenna for 40-10 meters.

KH6JRM's Amateur Radio Antenna Topics: A tuned counterpoise antenna for 40-10 meters In my last post, I related the experience of making a segmented inverted v dipole antenna covering the 20, 15, and 10 meter bands.  The antenna required some adjustment, particularly in the 20 meter segment, which was cut a bit short.  With all the segments connected together with alligator clip leads, I found the 20 meter section approximately 5 inches (12.7 cm) short on each side.  With the addition of some extra wire, the 20 meter section tuned up nicely on 14.200 Mhz.  It pays to cut your antenna elements a few inches (several centimeters) longer than expected. After using the segmented v for a few hours, I lowered the mast and stored the antenna segments in some plastic storage bins near the radio room.  I can reassemble this antenna again if the need arises. A NEW ANTENNA Since my backyard is rather small, I prefer verticals, inverted vees, and loops for most of my HF work.  The on

Antenna Topics: A 20, 15, and 10 meter segmented inverted vee dipole. Post #187

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

Antenna Topics: A simple multi-band inverted V dipole for 40 and 15 meters, post # 186

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

Antenna Topics: A simple 15 meter vertical dipole, post #185

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