2004 ARRL 160 Meter Contest etc
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I made some improvements to the station for this contest including a new BOG and improved Beverage matching transformers plus a better match on the shunt fed Rohn 25 tower (108 feet with a 10 foot T mast). Also, I permanently wired in a new 160 meter preamplifier .
Before the contest I read a propagation forecast that predicted geomagnetic condx could be undisturbed for the period of the contest. When I got on the noise seemed low and remained so during the whole contest. I got a lot more motivated after the first two hours at rates of 138 and 120. Signals to Europe were pretty weak and peaked up and down for the whole contest. It seemed like conditions to the NW were better than usual and some W6 stations were quite loud. Only one DX station DF2PY called me during the whole contest. I missed about 3 or 4 DX countries that I called and did not come back.
This was the first time I seriously tried out a BOG - Beverage on the ground antenna. I just laid out the longest wire I could at around 45 degrees (about 300 feet ?) - it was considerably shorter than my 1000 foot EW and 650 foot 60 degree Beverages. I measured the input impedance of the BOG at around 225 ohms (a good average for 160 to 40 meters) and terminated it in a 220 ohm 2 watt carbon resistor to a 5 foot ground rod. I was able to better copy two DX stations ( they turned out to be two new multipliers ) on it than on the other Beverages - the external preamplifier and the FT1000 preamp were both needed. I am considering phasing two BOGs as an experiment for the Stew Perry TopBand DX Challenge This antenna seems to provide around 15 dB less signal (to EU) than the 1000 ft EW Bev and really needs a lot of preamplification. It probably deserves more experimentation although it was only best for two contacts during the whole contest.
I had previously extended my short NW/SE Beverage (about 250 feet) with an boglike extension. This consists of about another 250 feet on the ground (on my neighbors land) in the SE direction (unterminated) and fed from the NW end. This extension seems to help quite a bit. The EW beverage has two feedlines - one at each end and no terminations. Both feedlines are always attached to the antenna and provide very good directivity by simply selecting the east or west feedline. The W feedline is about 1300 feet of RG6 and the E feedline is about 250 feet.. Both directions work well without any preamplifier but sometimes I feel the external preamplifier helps - when copying a VK for example.
Future improvements include better ergonomics of my receiving antenna selection ( I currently use two manual switches - quite unsatisfactory), increasing power to 1500 from 1000W, more radials on the vertical and increasing the amount of operating time.
I hope to refine this page and add more useful and interesting stuff to my web pages with emphasis on 160 Meters, contesting and historic ham items from my collection.
73, N8EA
73 joe n8ea n8ea@arrl.net
Updated 16 June 2009