K3KY's Short Beverage|
Originally planned as an 80/160 Beverage, this antenna
is a terrific performer on 40 and 30 meters, plus...
I live on a medium size, rectangular lot (0.8 acres) and am
fortunate to have many large, old trees, some over 100 feet tall.
They have supported many successful wire antennas over the years. I had
written off the possibility of having Beverage antennas for the low bands,
however, because the longest side of the yard is only 216 feet long.
This seemed too short even for good 80 meter performance. On 80 and 160 I made do
with various smaller low noise receiving antennas, such as Ewes, the K6STI
horizontal loop (QST, Sep 95, p.33), and various wires and yagis for the
higher bands. Each helped to tease the DX out of the noise at times, but it
was frustrating to see packet spots for stations other hams were working that
I simply could not hear.|
I read some emails on the lowband reflector about using long wires laid on the ground as unterminated (bidirectional) Beverages, and remembered reading an interview in which Harold Beverage said that his first antenna was just a very long wire on the ground. I decided it could not hurt to at least try one. I drew up plans for my 'trespass Beverage', which involved sneaking around after dark with 300+ foot lengths of wire to be laid across neighbor's yards. There were two antenna possibilities, both 550 feet long- one at about 170° and the other about 20°. The 20° design won out because Europe is a more useful antenna heading from the US east coast. It also looked a lot easier to deploy the wire. It would cross our street and run parallel to another street that 'tees' with ours right in front of our house, just nicking the edges of two properties fronting on that street. After much surveying, I worked out a straight line course that could also be extended to about 700 feet with one additional street crossing.
I put up 225 feet of wire in our yard, starting from a back corner and ending near the center of the front yard. It angles up from ground level for about 40 feet, averages 6-8 feet high, and slopes back down to the ground. Fortunately, this is a low traffic area, and the wire runs through trees, bushes and the like, so there is little danger of people getting snagged on it. I also cut a 330 foot length of wire for the on-ground portion. I was worried about the possibility of attracting unwanted attention from the neighbors, or even worse, snagging a passing car with the wire. I worked out methods for quickly deploying and retrieving the wire, and for staking it at the road crossing to pull it snug to the ground. I planned to try various lengths and configurations including non-terminated and resistively terminated to resonant wires.
Then I remembered an article about a successful, short, 175 foot Beverage for 40 meters used by a ham in KH0 to knock down the loud JA's so he could work the USA (Ham Radio, Jul 79, p.40.) I decided to test the 225 foot elevated wire first, before adding the on-ground wire. I set up a 4 foot ground rod, some short, random length radials, and a 470 ohm resistive termination. It was amazing how well it worked on 30 and 40, producing solid copy on QRP Eu stations that were marginal on my high transmitting antennas in noisy conditions. I was surprised to learn it could often pull weak signals out of the noise on 80 and 160 too, though the output signal levels are not as great as those from a longer wire, and it is not as directive as on 40 and 30 meters. This has been one of my best low noise receiving antennas, and I find it useful for a variety of bands and circumstances. I may get around to trying the additional on-ground wire eventually. :-)
What I learned from my low band DXing is that it pays to experiment- trying many different antennas will show what works best at your station. I learned that propagation varies so much on 80 and especially 160 that antennas which work well one day may not the next day. Having a number of different receiving antennas to choose from is a good idea. Finally, I learned that it is a myth that it takes a big Beverage antenna farm to work lots of DX on the low bands- but it certainly does not hurt to have them! :-)
Update: 18 Mar 2009
For 80 and especially 160 meters, this 225 foot 'shorty Beverage' would work much better as a 'BOG' (Beverage on ground). A height of about 1 inch (2.54 cm) above ground would be good, using insulated wire. Output from a BOG antenna is lower, so using a receive preamp with it is necessary. I intend to play with some BOG antennas this year.
My original shorty Beverage is still up and continues to work great, especially on 40 and 30m.
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