2015 ARRL 160 Meter Contest Results

I use either a 160 Offcenter fed dipole at 38 ft. Or an Inverted-L (35 up and 85 over) with two radials. It works better when I can elevate the radials about ten ft. Above ground. For receive, I use either of the antennas, or a home brew tuned shielded magnetic loop about five ft. Above ground. The loop is made of 20 ft. Of RG8 with the shield split at the top, with tuning/matching network tuned with varactor diodes. The system works OK, but I have lots of hvac motor and other noise sources on 160 at the qth.

From what I have read, using as few as two or four elevated radials (about 8-10 ft. above the ground) increases efficiency over buried radials. until you get to about 32 in-ground radials.  

I have proven this on my 40 meter vertical with only 4 radials at 8-10 ft.
On the 160 inverted 'L', I can manage 2-3 temporary radials, even though they are bent to a 90 degree angle after about 65 ft.  I quickly angle them up to 8-10 ft for the first 10 ft. and then support them with 1/2 inch electrical conduit shoved about a foot into the ground every 20 ft or so to keep them from clothes-lining people in my backyard.  After 160 season, I roll the inverted 'L' and radials up on an electrical cord reel and store them until the next season....

When I just lay them on the ground, I don't get as good performance.  I haven't been able to fully understand the radiation efficiency difference, but it seems it has to do with ground capacitance, etc.... I still need to do some more study.  But I am contemplating doing the same thing with an 80 meter inverted 'L.'  I think I may be able to squeeze 4 elevated radials into the yard, somewhat bent, perhaps using two of the 160 radials as part of the system this winter.

Perhaps some of the other 80/160 experts will chime in with some suggestions?