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Near Vertical Incident Skywave (NVIS) HF transmissions are very difficult (likely impossible) to track from the ground. They go almost straight up. Hams call th
by w8rbt 10y ago
Near Vertical Incident Skywave (NVIS) HF transmissions are very difficult (likely impossible) to track from the ground. They go almost straight up. Hams call them cloud burners. However, they are limited to 200 - 400 mile radius.
https://en.wikipedia.org/wiki/Near_vertical_incidence_skywave https://en.wikipedia.org/wiki/Near_vertical_incidence_skywav...
You'd need a dipole (14 AWG wire) about 5 meters above the ground or an 80 meter loop about 10 meters up. If setup right, the antenna would be difficult to detect as well.
Edit: I'm a Ham. I build wire antennas as a hobby. It's fun.
- jdietrich 10y agoEarth-Moon-Earth or exotic digital modes are also a possibility. EME is impossible to triangulate if you're using a suitably directional antenna. A creative interpretation of the Shannon-Hartley theorem allows for communication below the noise floor using low symbol rates and wide bandwidth. LF and below is difficult to triangulate because of the huge wavelengths, but a workable antenna would be rather conspicuous. You might also get lucky with meteor scatter or sporadic E.