Loop Plots

The Plots Thicken

10 meter loop at 1.5 meters above ground, mostly vertical polarization.

I find in practice however, that the nulls are not as sharp as shown here.

10 meter loop at 6 meters above ground, the pattern looks very useful.

I have tried the antenna in the horizontal position at 5 meters above ground, first thing I noticed was a substantial reduction in noise, and the useful bandwidth also increased .

The same antenna shown at right on 15 meters.

Note the stronger high angle horizontal lobes.

I also find that the SWR curve in the real world is a little broader than shown here.

For illustration purposes only, same antenna on 20 meters.

The horizontaly polarized lobes are further developed as the antenna becomes more like a proper Small Transmitting Loop.

This particular antenna is not practical at these frequencies.

VK2YOC

Contact

These are the .nec files for this antenna, they are reasonably close to the actual antenna behaviour.

Copy and paste to a text file and rename with a .nec extension. First is for the loop in the vertical plane, the second is in the horizontal plane and is omni-directional, but needs to be higher than, the other, about as high as a dipole would do.

GW 1 1 0.0799 0 1.8711 0.2254 0 1.8146 0.01

GW 2 1 0.2254 0 1.8146 0.3381 0 1.7066 0.01

GW 3 1 0.3381 0 1.7066 0.401 0 1.5638 0.01

GW 4 1 0.401 0 1.5638 0.4044 0 1.4078 0.01

GW 5 1 0.4044 0 1.4078 0.3478 0 1.2623 0.01

GW 6 1 0.3478 0 1.2623 0.2399 0 1.1496 0.01

GW 7 1 0.2399 0 1.1496 0.0761 0 1.0867 0.01

GW 8 1 0.0761 0 1.0867 -0.08 0 1.0833 0.01

GW 9 1 -0.08 0 1.0833 -0.204 0 1.1399 0.01

GW 10 1 -0.204 0 1.1399 -0.317 0 1.2478 0.01

GW 11 1 -0.317 0 1.2478 -0.38 0 1.3906 0.01

GW 12 1 -0.38 0 1.3906 -0.383 0 1.5467 0.01

GW 13 1 -0.383 0 1.5467 -0.327 0 1.6921 0.01

GW 14 1 -0.327 0 1.6921 -0.219 0 1.8049 0.01

GW 15 1 -0.219 0 1.8049 -0.076 0 1.8677 0.01

GW 16 1 -0.076 0 1.8677 0.0799 0 1.8711 0.01

GW 17 1 0.02113629 0 1.23880791 0.05510504 0 1.20657278 0.01

GW 18 1 0.05510504 0 1.20657278 0.05633089 0 1.15975959 0.01

GW 19 1 0.05633089 0 1.15975959 0.02409576 0 1.12579086 0.01

GW 20 1 0.02409576 0 1.12579086 -0.0227174 0 1.12456501 0.01

GW 21 1 -0.0227174 0 1.12456501 -0.0566862 0 1.15680013 0.01

GW 22 1 -0.0566862 0 1.15680013 -0.057912 0 1.20361332 0.01

GW 23 1 -0.057912 0 1.20361332 -0.0256769 0 1.23758206 0.01

GW 24 1 -0.0256769 0 1.23758206 0.02113629 0 1.23880791 0.01

GE 0

LD 5 0 0 0 3.77e7 0.01 1.3e-11

LD 0 16 1 1 0 0 1.323e-11

EX 0 24 1 0 1 0

GN 2 0 0 0 13 0.005

FR 0 1 0 0 28.5 0

GW 1 1 0.0799 -1.8711 6 0.2254 -1.8146 6 0.01

GW 2 1 0.2254 -1.8146 6 0.3381 -1.7066 6 0.01

GW 3 1 0.3381 -1.7066 6 0.401 -1.5638 6 0.01

GW 4 1 0.401 -1.5638 6 0.4044 -1.4078 6 0.01

GW 5 1 0.4044 -1.4078 6 0.3478 -1.2623 6 0.01

GW 6 1 0.3478 -1.2623 6 0.2399 -1.1496 6 0.01

GW 7 1 0.2399 -1.1496 6 0.0761 -1.0867 6 0.01

GW 8 1 0.0761 -1.0867 6 -0.08 -1.0833 6 0.01

GW 9 1 -0.08 -1.0833 6 -0.204 -1.1399 6 0.01

GW 10 1 -0.204 -1.1399 6 -0.317 -1.2478 6 0.01

GW 11 1 -0.317 -1.2478 6 -0.38 -1.3906 6 0.01

GW 12 1 -0.38 -1.3906 6 -0.383 -1.5467 6 0.01

GW 13 1 -0.383 -1.5467 6 -0.327 -1.6921 6 0.01

GW 14 1 -0.327 -1.6921 6 -0.219 -1.8049 6 0.01

GW 15 1 -0.219 -1.8049 6 -0.076 -1.8677 6 0.01

GW 16 1 -0.076 -1.8677 6 0.0799 -1.8711 6 0.01

GW 17 1 0.02113629 -1.2388079 6 0.05510504 -1.2065728 6 0.01

GW 18 1 0.05510504 -1.2065728 6 0.05633089 -1.1597596 6 0.01

GW 19 1 0.05633089 -1.1597596 6 0.02409576 -1.1257909 6 0.01

GW 20 1 0.02409576 -1.1257909 6 -0.0227174 -1.124565 6 0.01

GW 21 1 -0.0227174 -1.124565 6 -0.0566862 -1.1568001 6 0.01

GW 22 1 -0.0566862 -1.1568001 6 -0.057912 -1.2036133 6 0.01

GW 23 1 -0.057912 -1.2036133 6 -0.0256769 -1.2375821 6 0.01

GW 24 1 -0.0256769 -1.2375821 6 0.02113629 -1.2388079 6 0.01

GE 0

LD 0 16 1 1 0 0 1.3e-11

EX 0 24 1 0 1 0

GN 2 0 0 0 13 0.005

FR 0 1 0 0 28.5 0