As you know I use (d) the Imax 2000 with radials for 10-17 meters on the roof.
Since 10/12/15 worked good but 17 already saw a decrease in efficiency I decided to make something nw.
It became the 31 foot vertical made partly of titanex alu tubing very strong and almost indestructible as used in my 77 foot inverted L.
Tested several 1:4 unun's piccie is of the test T200-2 core, with Teflon wire on it.
Last and chosen unun is the FT240 -43 core with 11 bifilar windings on it as 1:4 unun.
Bagged me testing on 15 meters Bear island with 5 watts...... not intended, but just happened.
Since this summer will see a complete redo and maintenance on the roof it will replace the Imax antenna for 40 - 10 it even has a good SWR on 6 and 4 meters, though the radiation pattern there might be a bit iffy....;)
Why 31 foot? I wanted to stay below the full 10 meter length, so it still gets a decent 10 meter pattern.
31 feet so the swr on 40 is now 1:2.5 measured with the MFJ 269 analyser at the balun can easily be tuned flat.
Made a 1:1 choke with a FT 240 - 43 core and RG 58 with 10 windings on that to keep the coax from getting RF on the outside.
Testing it here on the ground between the houses looking quite good, swr never higher as 1: 1.3 except 40 meters.
Could tune it even on 160, but will work as a leaky dummy load there with the 9.5 meters radiator.
So, why is everyone not building/making/testing homebrew antenna's here?
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