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NOFARS 2007 FIELD DAY
TEN NOFARS MEMBERS SCORE IN FIELD DAY Field Day results have been released by ARRL. NOFARS members accounted for 24% of all Field Day entries received from operators in the Northern Florida section. The ten NOFARS entries also was the highest total since we started our decentralized system in 2004. Call Class Contacts Points N4UF 1B1 518 2,186 Fifth place 1B1 overall in US and Canada KF4AAF 2A 416 1,890 WA4B 1E 212 524 KA5PNE 1C 38 415 17th place 1C overall in US and Canada KD4FBI 1E 170 390 N4MUH 1E 104 314 N4CDB 1E 18 186 WB4DHI 1D 84 147 W4EJY 1C 13 76 K4GOP 1D 19 38 .-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-. The ARRL Field Day rules recognize six categories. A single-transmitter operation using three or more operators on backup power with a temporary antenna is an example of class A. A one or two-person operation using backup power with temporary antennas is class B. A mobile operator participates as class C. Those operating their home stations using permanent antennas and regular power belong in class D. A home station using backup power and permanent antennas operates in the class E category. Field Day participation from an official emergency operations center is class F. In 2007, NOFARS members participated in all categories except F. .-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-. PORTABLE HF ANTENNAS SLOPING DIPOLE The sloping dipole (sloper) is a cheap and simple antenna for both base and portable use. It stores very easily and consists of a center insulator and two wire segments. It can be hung from a tree branch or most any support. Only one support is needed, the other end is attached close to the ground. Use RG-8, RG58 type of 50-52 ohm coax. Even RG-59 cable TV coax (72-75 ohms) can be used with little degradation, especially if a tuner is used. Nylon twine can be used to secure the two ends of the sloper. Be sure and mark any low wires or ropes well to provide a warning. A 40 meter sloper usually will also cover 15 meters, so this is the first one to consider. Each wire segment should be around 33 feet long. Total length is around 66 feet. It is good to include an extra three inches or so on each wire segment to facilitate end and center connection loops. Wire can be copperweld type stranded bare wire or scrap electrical cable. Even unshielded speaker wire is satisfactory. Aluminum wire can be used but may cause complications when making connections. Unless you are running high power (over 200 watts), the wire diameter is not of much importance. The main consideration about wire thickness is keeping the wire from stretching or breaking easily from stress. Both wire segments should be exactly the same length. Cut one segment with a ruler/tape measure. Then cut the second segment using the first as a guide. A drilled segment of PVC pipe can be used as a center insulator. A 3 inch segment of 3/4 or 1 inch diameter PVC works well. Pig tail the two coax conductors to the two center leg connections. The wire segment to be hoisted the highest should be electrically connected to the coaxial cable center conductor. See the diagram below. You can dog leg the wire segments to fit in a small lot, although this should not be done unless unavoidable. Field Day is a good time to construct your own sloper. And then try it out on the air. If you live in a restricted area, portable antennas may be legal for a short duration. After FD is over, roll up your sloper and store in a plastic box. Or set up in a park or operate from your car parked near the beach. You'll be ready to go even if your normal antenna is damaged during a storm. If you also have a source of backup power, then you may be of valuable service to your neighbors when serious utility disruptions occur. Other sloper lengths include: 80 meters (3.9 MHz)------60 ft. for each wire segment (120 ft. total wire length) 20 Meters (14.2 MHz)-----16 ft. 6 inches for each wire segment (33 ft. total wire length) 10 Meters (28.4 MHz)-----8 ft. 3 inches for each wire segment (16 ft. 6 inches total length) 6 Meters (50.2 MHz)------4 ft. 7 inches for each wire segment (9 ft. 2 inches total length)
Formula for total wire length (X to Z): 468 divided by the frequency in Megahertz
X------------------------Y-------------------------Z
Above: XY and YZ are wire segments. Attach nylon rope or twine to points X and Z.. Y is the feedpoint. Attach 50 or 75 ohm coaxial cable. The X ended wire segment should attach to the center conductor of the coaxial cable at the Y feedpoint. The Z ended wire segment should attach to the outer shield of the coaxial cable at the Y feedpoint. The X end nylon twine should be placed as high as possible such using a tree branch, mast or other support. 20 to 30 feet of elevation is ideal. The Z end nylon twine should be attached to a point near the ground. Or if a second support structure is available, both ends can be raised to form a basic dipole configuration. Some hams have used wire dipole antennas in their attic with reasonable results when band conditions are above average. There are sloper configurations that provide directionality and gain. Consult a search engine for sources of information.
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