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40m Antenna Comparison

John Corby
 

Gadzooks! Snow almost gone and southern Ontario daytime temperatures above freezing! So I hauled wire, poles and radio into the backyard for a comparison test. These are the antennas I tested:
1. Vertically polarized Delta loop
2. Half Rhombic (full wave, end fed wire, center supported at 23ft with ends up about 6 feet)
3. End Fed Full Wave wire up 8ft
4. Quarter wave sloping vertical

All four antennas produced multiple RBN spots but the Delta loop was the clear winner both in distance and signal strength of reception reports (up to 24dB S/N). The half Rhombic was a good second and the End Fed Full Wave wire came a close third. All three used the same 137ft wire. In last place was the quarter wave sloping vertical which produced disappointing results but used only 33ft of wire worked against ground through a GTU (Ground Tuning Unit - a series connected LC tuner). All tests were done at 5 watts.

Tomorrow I plan to hold my first outdoor operating session of the season in a place where the ground is solid 3 billion-years-old Canadian Shield rock. That will be a new challenge that will really put the Delta loop to the test. If you're around during the early afternoon (Eastern Time zone) listen up for me around 7.030MHz CW.

John, VA3KOT