Tiny Elephant's Contest Corner

The Latest Contest News -
A NARC Bulletin Exclusive

A monthly column by Ed Deichler, K2TE

I have been reading some of my off-hand comments in my last two columns regarding the weather and it seems I’m a bit of a prophet when it comes to snow. We are approaching mid-February and, thankfully, there is not as much snow piled up as a month ago. What there is, however, is hard as stone. Its too bad all that snow had to leave so quickly and spoil some of the best antenna weather we have had in years. No, the tiny elephant hasn’t been standing out in it too long; the stuff would make a great cushion if I miss a rung on the tower.

In between running the snowthrower and looking for some low-band DX, I have been playing with an antenna modeling program that I bought several months ago. The program is called ELNEC, developed and sold by Roy Lewallen, W7EL. I became interested in ELNEC from some articles in QST about modeling antenna systems and working with the MININEC program. ELNEC is one of a family of modeling programs that Roy has worked on over the years. It is a more sophisticated version than the earlier MININEC program that is available as shareware. Both programs are relatives of a more powerful (and expensive) program called NEC. These programs uses numerical estimation techniques to calculate far-field patterns for antenna systems ranging from a simple dipole to yagi arrays. Variants of NEC, such as NEC2 and NEC3, allow a user to model elevated and buried ground radial systems for vertical antenna designs. At first thought, such models sound straightforward; however, the earth is anything but homogeneous, so that characterizing the dielectric constant and characteristic impedance of the ground over several hundred feet around a tower involves some ugly math. ELNEC and MININEC can’t handle radials whereas the NEC versions can.

I have found the ELNEC program to be useful for providing a feel for how an antenna should perform. The program is easy to use ; Roy’s “test drive” tutorial takes about 15 minutes and is enough to be off and modeling. The program features different ground conductivity characteristics (e.g., loam, marsh, mountain soil, etc.), selection of conductor materials and sizes, current source placement options, rotatable 3-D views of an antenna, and polar plots of the far-field pattern (azimuth or elevation cuts available). The program builds an antenna using straight segments, both for a wire antenna and for beams. Each piece is further broken down into more segments that the program uses to compute the contributions of the antenna currents. The more segments selected, the better the pattern and impedance calculations at the cost of longer computation time. However, it is not necessary to use, say, 50 segments to really fine-tune things if there is little difference over a 10-segment iteration.

I have been playing around with ELNEC to model an inverted L antenna for 160 meters that I want to put up in the Spring. The program allows me to adjust the length of the horizontal and vertical parts as well as the angle of the horizontal part with respect to the ground. I found some design examples in ON4UN’s book Low Band DXing that helped me determine if I was doing things the right way. One drawback I have found is that the model is most accurate for calculations that assume a perfect ground and lossless conductors. Therefore, what I actually end up with may differ significantly in performance over what the model says. Nonetheless, I should be able to find out what adjustments are most sensitive when it comes to impedance and SWR calculations. The idea is to come pretty close the first time in the hope of avoiding 1600 meters worth of tower climbing to tweak the antenna.

While I dream of the “ultimate” antenna for 160, I continue to exercise the rest of the antenna farm. As we March forward toward Spring, here are several contests that should give me plenty of fun:

ARRL International SSB DX Contest, 2-3 March.

The fourth DX megacontest of the season is another full weekend, this time for the “code-a-phobiacs”: the ARRL SSB DX contest. The objectives and features of the contest are the same as the CW DX contest two weeks ago. Categories include single operator, single operator assisted (using packet), and several classes of multioperator (one transmitter, two transmitter, and unlimited). Multioperator classes are restricted to a 10-minute band change rule. Single operator stations are not restricted to the 10-minute rule and may operate QRP (<5W), low power (<150W), or high power. The exchange is RST and state for us, RST and a 3-digit number representing output power for the DX stations. Contest results should be to the ARRL contest branch via paper, disk, or Internet at contest@arrl.org.

BARTG Worldwide RTTY Contest, 16-18 March.

The British Amateur Radio Teledata Group sponsors a 48-hour event that is very similar to the CQ Worldwide contest series. The contest starts 0200Z on Saturday (no need to rush dinner) and ends 0200Z on Monday, the 18th. The “usual” classes of station entries - single operator/all band, single operator/single band, multioperator, single transmitter, and multi-multi - are allowed. Only the multi-multi stations can operate the entire 48 hours while everyone else is limited to 30 hours. Operation is permitted on 10 through 80 meters. Contest exchange is signal report, QSO #, and time in UTC. Multipliers, applied to each band, are the number of DXCC countries plus call districts/provinces plus the number of continents worked (6 maximum). G4SKA is the contest manager who will be looking for contest logs.

CQ Worldwide SSB Prefix Contest, 30-31 March.

CQ Magazine’s 48-hour “alphabet soup” contest to work as many different call prefixes as possible rounds the end of the month. The contest is limited to a maximum of 36 hours for all categories except multi- multi stations. The exchange is simply a signal report and 3-digit serial number. Stations are permitted to operate on 10 through 160 meters, with scoring counting twice as much on 40, 80, and 160 meters versus 10, 15, and 20 meters. Multipliers are the total number of prefixes worked and they count once regardless of how many bands. Scoring:

Multiply the total number prefixes times the following point totals: 1 point/QSO, and 2 points/QSO for 40 - 160 meters, on the same continent; 2 points/QSO and 4 points/QSO, respectively, for contacts with other stations on the North American continent; and 3 points/QSO and 6 points/QSO for DX contacts on the appropriate bands. Contest logs go to

CQ Magazine, 76 N.
Broadway, Hicksville, NY 11801

This looks like enough to satisfy my contest appetite. Hopefully I will be ready to start antenna work when the wind and rain of April roll in.

73 and happy contesting !!

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